INSERT INTO `course_notes_content` (`id`, `topic_id`, `content`, `markdown_format`, `created_at`, `updated_at`) VALUES
(73, 11208, '# लक्ष्मीप्रसाद देवकोटा - कक्षा १० (पूर्ण विस्तृत गाइड)\n\nनेपाली साहित्यका महाकवि लक्ष्मीप्रसाद देवकोटाको यो जीवनीले विद्यार्थीहरूलाई उहाँको असाधारण साहित्यिक योगदान र नेपाली आधुनिक साहित्यमा उहाँको अग्रणी भूमिकाबारे परिचय गराउँछ। यो विस्तृत गाइडले जीवनीका हरेक पक्ष, मुख्य विषयवस्तु, विश्लेषण र अभ्यासका सबै प्रश्नहरूको गहन र पूर्ण उत्तरहरू समावेश गर्दछ, जसले विद्यार्थीहरूलाई देवकोटाको विरासतको कदर गर्न र अध्ययनमा उत्कृष्टता हासिल गर्न मद्दत गर्नेछ।\n\n---\n\n## शब्दभण्डार (Vocabulary)\n\n### १. दिइएका शब्द र तिनका अर्थबिच जोडा मिलाउनुहोस् :\n\n| **शब्द** | **अर्थ** |\n| :--- | :--- |\n| युगपुरुष | कुनै निश्चित समयसीमाभित्र महान् व्यक्तित्व स्थापित गर्न सफल व्यक्ति |\n| नक्षत्र | ज्योतिष शास्त्रअनुसार मानिसको असल खराब अवस्थाका सूचक |\n| जीवन | शरीरमा प्राण रहेसम्मको अवस्था |\n| धडाधड | चाँडो चाँडो काम सिध्याउने गरी, धमाधम |\n| म्याट्रिकुलेसन | हालको एस.ई.ई. सरहको परीक्षा |\n| प्रज्वलित | एकदम बलेको, दन्केको |\n| परिवेष्टित | चारैतिरबाट घेरिएको |\n\n### २. रेखाङ्कन गरिएका सङ्क्षिप्त शब्दका पूरा रूप लेखी पुनर्लेखन गर्नुहोस् :\n**उत्तर:** **राष्ट्रिय समाचार समिति**का पत्रकार मोहन **प्रधानमन्त्री**को अन्तर्वार्ता लिएर घर गए। उनकी श्रीमती रमा जनता **माध्यमिक विद्यालय**मा **प्रधानाध्यापक** थिइन्। **विद्यालय व्यवस्थापन समिति**को बैठक सकेर निस्कँदा उनलाई ढिलो भएछ। बाटामा **त्रिभुवन विश्वविद्यालय**का **उपप्राध्यापक** दावासँग र **प्रमुख जिल्ला अधिकारी** रमेशसँग रमाको भेट भएछ। उनीहरू एकछिन कुराकानी गरेर आआफ्ना घरतिर लागेछन्। रमा घर पुग्दा पत्रकार मोहन **गोरखापत्र**मा प्रकाशित समाचार पढेर बसेका रहेछन्।\n\n### ३. दिइएका पद पदावलीलाई आशय खुल्ने गरी वाक्यमा प्रयोग गर्नुहोस् :\n* **पठनपाठन:** कोरोना महामारीका कारण लामो समयदेखि विद्यालयमा **पठनपाठन** अवरुद्ध भएको थियो।\n* **देहावसान हुनु:** राष्ट्रकवि माधवप्रसाद घिमिरेको १०१ वर्षको उमेरमा **देहावसान भएको थियो**।\n* **मन्त्रमुग्ध पार्नु:** उस्तादको शास्त्रीय सङ्गीतले सबै स्रोतालाई **मन्त्रमुग्ध पार्‍यो**।\n* **स्वर्णकाल:** धेरै मानिसहरू आफ्नो बाल्यकाललाई नै जीवनको **स्वर्णकाल** मान्छन्।\n* **भुलभुलैया:** भौतिक सुखसुविधाको यो संसार एक **भुलभुलैया** जस्तै हो, जहाँ मानिस हराउन सक्छ।\n* **नवजात शिशु:** **नवजात शिशु**लाई न्यानो र हेरचाहको अत्यधिक आवश्यकता पर्दछ।\n\n---\n\n## बोध र अभिव्यक्ति (Comprehension and Expression)\n\n### १. दिइएका घटना कुन-कुन सालमा भएका हुन्, जीवनीका आधारमा लेख्नुहोस् :\n\n* **लक्ष्मीप्रसाद देवकोटाको जन्म:** वि.सं. १९६६\n* **अङ्ग्रेजी पढ्न दरबार हाइस्कुलमा भर्ना:** वि.सं. १९७७\n* **मनदेवी चालिसेसँग विवाह:** वि.सं. १९८१\n* **म्याट्रिकुलेसन परीक्षा उत्तीर्ण:** वि.सं. १९८२\n* **आई.एस्सी. परीक्षा उत्तीर्ण:** वि.सं. १९८५\n* **डा. के.आई. सिंहको मन्त्रिमण्डलमा शिक्षामन्त्रीमा नियुक्त:** वि.सं. २०१३\n* **अफ्र्रो-एसियाली लेखक सम्मेलनमा सहभागी:** वि.सं. २०१५\n\n### २. दिइएका प्रश्नको विस्तृत उत्तर लेख्नुहोस् :\n\n**(क) लक्ष्मीप्रसाद देवकोटाको व्यक्तिगत जीवनमा कस्ता-कस्ता उतारचढाव आए?**\n**उत्तर:** महाकवि लक्ष्मीप्रसाद देवकोटाको साहित्यिक जीवन जति चम्किलो थियो, व्यक्तिगत जीवन त्यति नै सङ्घर्षपूर्ण र उतारचढावले भरिएको थियो। उनले जीवनमा पारिवारिक, स्वास्थ्य र आर्थिक क्षेत्रमा ठुला समस्याहरू भोगे। २५-२६ वर्षको कलिलो उमेरमा नै उनले आफ्ना बुबा, आमा र छोरीलाई गुमाउनु पर्‍यो, जसले उनलाई गहिरो मानसिक चोट दियो। पारिवारिक वियोगको पीडा सहन नसकेर उनले केही समय मानसिक सन्तुलन समेत गुमाए, जसका कारण उनले समाजबाट \'पागल\' को संज्ञा पनि खेप्नुपर्‍यो।\n\nआर्थिक रूपमा उनी सधैँ अभावग्रस्त रहे। लक्ष्मीपूजाका दिन जन्मे पनि जीवनभर उनलाई लक्ष्मी (धन) ले उपेक्षा गरिन्। जीवनको उत्तरार्धमा उनलाई क्यान्सर जस्तो घातक रोगले सतायो। एकातिर क्यान्सरको असह्य पीडा र अर्कोतिर उपचारका लागि आर्थिक सङ्कटले देवकोटालाई शारीरिक र मानसिक रूपमा प्रताड़ित गर्‍यो। यस्ता अनेकौँ पारिवारिक, आर्थिक र स्वास्थ्यसम्बन्धी उतारचढावका बाबजुद पनि उनले साहित्य सिर्जनालाई कहिल्यै रोकेनन्, जुन उनको महानताको प्रतीक हो।\n\n**(ख) देवकोटामा रहेको देशप्रेम र क्रान्ति चेतनाको वर्णन गर्नुहोस्।**\n**उत्तर:** महाकवि देवकोटा एक महान् साहित्यकार मात्र नभई एक सच्चा देशभक्त र क्रान्तिचेत भएका युगपुरुष पनि थिए। उनको देशप्रेम उनका हरेक कार्य र सिर्जनामा झल्किन्छ। नेपालको प्रकृति, संस्कृति र भाषा-साहित्यलाई उनले मुटुदेखि नै माया गरे। बिरामी भएर भारतमा उपचार गराउँदा समेत \"विदेशमा मर्नुभन्दा आफ्नै देशमा बसेर सेवा गर्छु\" भन्ने अठोट लिएर उनी काठमाडौँ फर्किएका थिए, जसले उनको गहिरो राष्ट्रप्रेम दर्शाउँछ।\n\nदेवकोटाको प्रतिभा तत्कालीन निरङ्कुश राणा शासनमा पनि कहिल्यै मुर्झाएन। जब देशमा प्रजातन्त्रका लागि क्रान्तिको आगो सल्किँदै थियो, उनले विद्रोहको बाटो समाते। उनी प्रजातान्त्रिक आन्दोलनमा सक्रिय रूपमा संलग्न भए र बनारसबाट प्रकाशित हुने \'युगवाणी\' पत्रिकामार्फत निरङ्कुशताविरुद्ध विद्रोहको आवाज बुलन्द गरे। उनले शिक्षामन्त्री हुँदा नेपाली भाषालाई पठनपाठनमा अनिवार्य गराउने जस्ता महत्त्वपूर्ण काम गरेर आफ्नो देशप्रेम प्रमाणित गरे। यसरी देवकोटाले आफ्नो कलम र कर्म दुवैबाट राष्ट्रको हित र परिवर्तनका लागि अविस्मरणीय योगदान दिए।\n\n**(ग) देवकोटालाई आशुकविका रूपमा चिनाउनुहोस्।**\n**उत्तर:** \'आशुकवि\' को अर्थ हो, तत्काल वा तुरुन्तै कविता रच्न सक्ने विलक्षण प्रतिभा भएको कवि। लक्ष्मीप्रसाद देवकोटा यो उपमाका लागि सबैभन्दा योग्य व्यक्तित्व हुन्। उनमा छाँगो छङछङाए झैँ वा बिजुलीको वेगमा जस्तै कविता सिर्जना गर्ने अद्भुत क्षमता थियो। उनी सामान्य कुराकानी गर्दागर्दै वा हिँड्दाहिँड्दै पनि धाराप्रवाह कविता लेख्न सक्थे। अझ भनौँ, उनी कवितै-कवितामा कुराकानी गर्न सक्थे।\n\nउनको यो क्षमताका केही विश्वप्रसिद्ध उदाहरणहरू छन्। उनले केवल **तीन महिनामा \'शाकुन्तल\' जस्तो विशाल महाकाव्य**, **१० दिनभित्रका ६० घण्टामा \'सुलोचना\' महाकाव्य** र **एकै रातमा \'कुञ्जिनी\' खण्डकाव्य** लेखेर सिध्याएका थिए। यति छोटो समयमा यति गहन र स्तरीय कृतिहरू रचना गर्नु सामान्य मानिसका लागि असम्भवप्रायः हो। उनको यही तत्काल सिर्जना गर्न सक्ने अद्वितीय र चमत्कारिक प्रतिभाका कारण उनलाई \'आशुकवि\' का रूपमा चिनिन्छ।\n\n**(घ) \'लक्ष्मीप्रसाद देवकोटा\' को जीवनीबाट कस्तो सन्देश पाइन्छ?**\n**उत्तर:** महाकवि लक्ष्मीप्रसाद देवकोटाको जीवनीले हामीलाई अनेकौँ प्रेरणादायी सन्देशहरू प्रदान गर्दछ। यसबाट पाइने सबैभन्दा ठुलो सन्देश हो - **प्रतिकूलतामा पनि निरन्तर साधना र सिर्जनामा लागिरहनुपर्छ।** देवकोटाले आफ्नो जीवनमा पारिवारिक वियोग, चरम आर्थिक अभाव र निरङ्कुश राजनीतिक अवस्था जस्ता ठुला सङ्घर्षहरू भोगे, तर पनि उनले उच्च स्तरका साहित्य रचना गर्न कहिल्यै छोडेनन्।\n\nयस जीवनीले हामीलाई आफ्नो देश, भाषा र संस्कृतिलाई माया गर्न र राष्ट्रको सेवामा सधैँ तल्लीन रहन प्रेरित गर्दछ। आफ्नो क्षमतालाई चिनेर अगाडि बढ्ने मानिसले जस्तोसुकै कठिन परिस्थितिमा पनि सफलता हासिल गर्न सक्छ भन्ने कुरा देवकोटाको जीवनले सिकाउँछ। मानवताको भाव बोकेर समाजका लागि निस्वार्थ योगदान पुऱ्याउन सक्नु नै मानव जीवनको सार्थकता हो भन्ने महान् सन्देश उनको जीवनीबाट पाउन सकिन्छ।\n\n### ७. व्याख्या गर्नुहोस् :\n\n**(क) देवकोटाको महासागर जस्तो प्रतिभा राणाहरूको निरङ्कुशताको साँघुरो सुरुङभित्र कसरी बग्न सक्थ्यो र ?**\n\n**प्रस्तुत सन्दर्भ:**\nयो वाक्यांश महाकवि लक्ष्मीप्रसाद देवकोटाको जीवनीबाट उद्धृत गरिएको हो। यसले देवकोटाको विशाल, अदम्य र सिर्जनशील साहित्यिक प्रतिभालाई तत्कालीन राणा शासनको दमनकारी र साँघुरो परिवेशले रोक्न नसकेको यथार्थलाई सङ्केत गर्दछ। जतिबेला देवकोटाको कलमको जादु सुरु भयो, त्यतिबेला नेपालमा राणाहरूको निरङ्कुश शासन चलिरहेको थियो।\n\n**विस्तृत व्याख्या:**\nयस वाक्यांशमा देवकोटाको प्रतिभालाई \'महासागर\' र राणा शासनको परिवेशलाई \'साँघुरो सुरुङ\' सँग तुलना गरेर एक शक्तिशाली बिम्ब खडा गरिएको छ। \'महासागर\' विशालता, गहिराइ र असीमित ऊर्जाको प्रतीक हो, जसले देवकोटाको बहुआयामिक र प्रचुर साहित्यिक क्षमतालाई जनाउँछ। उनी कविता, महाकाव्य, खण्डकाव्य, निबन्ध, नाटक, उपन्यास जस्ता अनेक विधामा उत्तिकै सशक्त थिए। उनको सिर्जनाको गति बिजुली वेगमा थियो र त्यसलाई कुनै साँघुरो सीमाले बाँध्न सक्ने थिएन।\n\nअर्कोतर्फ, \'साँघुरो सुरुङ\' तत्कालीन राणा शासनको प्रतीक हो, जुन अभिव्यक्ति स्वतन्त्रता विरोधी, दमनकारी र निरङ्कुश थियो। यस्तो प्रतिकूल समयमा खुलेर साहित्य सिर्जना गर्न पाइँदैनथ्यो। तर, देवकोटाको विद्रोही र क्रान्तिकारी चेतना त्यो सुरुङभित्र कैद भएन। मुलुकमा प्रजातन्त्र प्राप्तिका लागि क्रान्तिको आगो सल्किँदा, उनले पनि विद्रोहको बाटो समाते। उनी वि.सं. २००४ मा प्रजातान्त्रिक आन्दोलनमा संलग्न भए र बनारसबाट प्रकाशित हुने \'युगवाणी\' पत्रिकामार्फत निरङ्कुशता विरुद्ध विद्रोहको वाणी फुके। उनको संलग्नतामा काठमाडौँमा पुस्तकालय खोलेर राणाविरोधी चेतना फैलाउन खोज्दा \'लाइब्रेरी पर्व\' समेत घटाइएको थियो।\n\nजसरी महासागरको उर्लंदो छाललाई एउटा साँघुरो सुरुङले रोक्न सक्दैन, त्यसरी नै देवकोटाको विराट प्रतिभा राणा शासनको सीमाभित्र कैद हुन सकेन। बरु, त्यो सीमा तोडेर विश्वभर फैलियो र उनको जादुमयी स्पर्शले नेपाली साहित्यले विश्व साहित्यकै हाराहारीको प्रौढताको शिखर छुन पुग्यो।\n\n**(ख) हिउँको माझमा जन्मेको हाम्रो साहित्य कहिल्यै पनि एउटै पर्वत शृङ्खलाको भुलभुलैयामा बिलाउने छैन ।**\n\n**प्रस्तुत सन्दर्भ:**\nयो दूरदर्शी र महत्त्वाकाङ्क्षी भनाइ महाकवि लक्ष्मीप्रसाद देवकोटाले वि.सं. २०१५ मा तत्कालीन सोभियत सङ्घमा भएको \'अफ्र्रो-एसियाली लेखक सम्मेलन\' मा प्रस्तुत गरेका थिए। यो भनाइले नेपाली साहित्यप्रतिको उनको गहिरो विश्वास र यसलाई विश्वव्यापी मञ्चमा पुऱ्याउने उनको उत्कट चाहनालाई प्रस्तुत गर्दछ।\n\n**विस्तृत व्याख्या:**\nयस भनाइमा देवकोटाले नेपाली साहित्यको भविष्यबारे एक शक्तिशाली दृष्टिकोण प्रस्तुत गरेका छन्। \"हिउँको माझमा जन्मेको हाम्रो साहित्य\" भन्नुको अर्थ हो, नेपालको विशिष्ट भौगोलिक र सांस्कृतिक परिवेशमा सिर्जित साहित्य। तर, उनको विचारमा नेपाली साहित्य केवल हिमाल र पर्वत शृङ्खलाको साँघुरो घेरामा मात्र सीमित रहने छैन। \"एउटै पर्वत शृङ्खलाको भुलभुलैयामा बिलाउने छैन\" भन्नुको तात्पर्य हो, नेपाली साहित्य भौगोलिक र मानसिक रूपमा एक्लिएर वा विश्वबाट ओझेल परेर बस्ने छैन। बरु, यसले आफ्नो सिमाना तोडेर एसिया तथा अफ्रिकालाई समेट्ने साहित्यको \'असीम महासागर\' अर्थात् विश्व साहित्यको मूल प्रवाहमा सम्मिलित हुनेछ।\n\nयो उनको आत्मविश्वास र नेपाली साहित्यको मौलिक शक्तिमाथिको अटुट विश्वास हो। उनले नेपाली साहित्यको अन्तर्राष्ट्रियकरणको सपना देखेका थिए, जहाँ हाम्रो साहित्यले विश्वका अन्य साहित्यसँग हातेमालो गरेर अघि बढ्नेछ। उनको यो आँकलन थियो कि जब हाम्रो साहित्य विश्व-साहित्यको महासागरमा मिसिन्छ, तब त्यस महासागरद्वारा सिञ्चित भएर त्यो अझ बढी सुन्दर र सम्पन्न बनेर फेरि हाम्रै पहाडमा बर्सनेछ। यसले नेपाली साहित्यको विश्वव्यापी पहिचान र त्यसबाट प्राप्त हुने नयाँ ऊर्जालाई सङ्केत गर्दछ। यो भनाइ उनको साहित्यिक दूरदर्शिता र नेपाली साहित्यप्रतिको अगाध प्रेमको प्रतीक हो।\n\n### ८. लक्ष्मीप्रसाद देवकोटाको साहित्यिक योगदानको समीक्षा गर्नुहोस् ।\n**उत्तर:**\nमहाकवि लक्ष्मीप्रसाद देवकोटा (वि.सं. १९६६-२०१६) नेपाली साहित्यका एक विराट् प्रतिभाशाली र अतुलनीय योगदान दिने चिरस्मरणीय स्रष्टा हुन्। उनको योगदानलाई सङ्ख्यात्मक र गुणात्मक दुवै दृष्टिले समीक्षा गर्न सकिन्छ।\n\n**सङ्ख्यात्मक योगदान:** देवकोटा नेपाली साहित्यमा सबैभन्दा prolix अर्थात् प्रचुर मात्रामा लेख्ने स्रष्टा मानिन्छन्। उनले आफ्नो ५० वर्षे छोटो जीवनकालमा कविता, खण्डकाव्य, महाकाव्य, निबन्ध, कथा, उपन्यास, नाटक गरी साहित्यका लगभग सबै विधामा कलम चलाए। उनले ७०० जति फुटकर कविता, दर्जनौँ खण्डकाव्य र आधा दर्जन महाकाव्य रचना गरे। केवल तीन महिनामा \'शाकुन्तल\' र एकै रातमा \'कुञ्जिनी\' जस्ता कृति लेख्नुले उनको सिर्जनात्मक क्षमताको प्रचुरतालाई दर्शाउँछ।\n\n**गुणात्मक योगदान:** देवकोटाको योगदान केवल सङ्ख्यामा मात्र सीमित छैन। उनले नेपाली साहित्यमा नयाँ युगको सुरुवात गरे। उनी नेपाली साहित्यमा स्वच्छन्दतावादका प्रवर्तक हुन्। उनका \'मुनामदन\' खण्डकाव्यले त्यसबेलासम्म उपेक्षित रहेको झ्याउरे छन्द अर्थात् लोकभाकालाई साहित्यिक मूलधारमा स्थापित गर्‍यो र यो आजसम्मकै सर्वाधिक लोकप्रिय कृति बनेको छ। उनका \'यात्री\' र \'पागल\' जस्ता कविताले नेपाली कवितामा नयाँ दार्शनिक उचाइ प्रदान गरे। \'लक्ष्मी निबन्ध सङ्ग्रह\' ले नेपाली निबन्ध साहित्यमा नयाँ शैली र गहिराइ थप्यो। उनले आफ्नो कलमको जादुमयी स्पर्शले किशोर अवस्थामा रहेको नेपाली साहित्यलाई विश्व साहित्यकै हाराहारीको प्रौढताको शिखरमा पुऱ्याए।\n\n**अन्य योगदान:** साहित्य सिर्जनाका अतिरिक्त उनी त्रिचन्द्र कलेजका प्राध्यापक, शिक्षामन्त्री तथा नेपाल राजकीय प्रज्ञा प्रतिष्ठानका संस्थापक सदस्य पनि भए। यी हरेक भूमिकामा उनले राष्ट्र र नेपाली भाषा-साहित्यको हितमा काम गरे।\n\n**निष्कर्ष:** देवकोटाको कवित्व प्रतिभा, रचनाको परिमाण र गुणस्तर आज पनि अद्वितीय छ। उनले नेपाली साहित्यलाई जुन उचाइ र समृद्धि प्रदान गरे, त्यसका कारण उनी \'महाकवि\' का रूपमा सम्मानित छन् र नेपाली साहित्यमा उनको स्थान सर्वोच्च छ।\n\n---\n\n## भाषिक संरचना र वर्णविन्यास (Linguistic Structure and Spelling)\n\n### १. दिइएका रेखाङ्कित शब्दको कारक चिनाउनुहोस् :\n**अनुच्छेद:** **हरिले** **सिन्काले** **कान** कोट्यायो। ऊ **घरबाट** **अस्तपालमा** पुग्यो। **डाक्टरले** **उसलाई** **औषधी** दिए। **डाक्टरले** **उसलाई** भने, \"**आजदेखि** सिन्काले कान नकोट्याउनू नि।\"\n\n| **रेखाङ्कित शब्द** | **कारक** |\n| :--- | :--- |\n| हरिले | कर्ता कारक |\n| सिन्काले | करण कारक |\n| कान | कर्म कारक |\n| घरबाट | अपादान कारक |\n| अस्पतालमा | अधिकरण कारक |\n| डाक्टरले | कर्ता कारक |\n| उसलाई | सम्प्रदान कारक |\n| औषधी | कर्म कारक |\n| आजदेखि | अपादान कारक |\n\n### २. दिइएको अनुच्छेदलाई शुद्ध गरी पुनर्लेखन गर्नुहोस् :\n**अशुद्ध:** ग्यवाली षरले कछ्यामा आएर नेपाली भासा र शाहित्य पढाउनुभयो। उहाँको षिकाउने तरिका गजबकै छ। उहाँले पढाएको त क्षाङ्गै बुझिन्क्ष। दिनेस, उमेष र रिसिलाई पनि उहाँले पढाएको षारै मन पर्क्ष रे।\n\n**शुद्ध:** **ज्ञवाली** **सरले** **कक्षामा** आएर नेपाली **भाषा** र **साहित्य** पढाउनुभयो। उहाँको **सिकाउने** तरिका गजबकै छ। उहाँले पढाएको त **छ्याङ्गै** **बुझिन्छ**। **दिनेश**, **उमेश** र **ऋषि**लाई पनि उहाँले पढाएको **साह्रै** मन **पर्छ** रे।\n\n---\n\n## सिर्जना र परियोजना कार्य (Creative and Project Work)\n\n### १. दिइएका बुँदाका आधारमा इन्दिरा प्रसाईको जीवनी तयार पार्नुहोस् :\n* **नाम:** इन्दिरा प्रसाई\n* **जन्म:** वि.सं. २०१४ फागुन ३, दार्जिलिङ\n* **मातापिता:** दुर्गादेवी नेपाल र गणेशप्रसाद शर्मा\n* **शिक्षा:** एम.बी.ए. (त्रिवि)\n* **साहित्यिक विधा:** कथा, कविता, निबन्ध, उपन्यास, आदि\n* **विशेषता:** नारीवादी, सामाजिक र मनोवैज्ञानिक साहित्यकार\n* **सम्मान/पुरस्कार:** युवावर्ष मोती पुरस्कार, मैनाली कथा पुरस्कार, राष्ट्रिय प्रतिभा पुरस्कार आदि।\n\n**जीवनी: साहित्यकार इन्दिरा प्रसाई**\nआफ्नो प्रतिभा र सिर्जनाबाट साहित्यको क्षेत्रमा प्रसिद्ध नाम हो, इन्दिरा प्रसाई। उनको जन्म वि.सं. २०१४ फागुन ३ गते भारतको दार्जिलिङमा पिता गणेशप्रसाद शर्मा र माता दुर्गादेवी नेपालको कोखबाट भएको थियो। जन्मथलो भारत भए पनि उनले कर्मथलो नेपाललाई बनाइन् र हाल काठमाडौँको अनामनगरमा बसोबास गर्दै आएकी छिन्। उनले त्रिभुवन विश्वविद्यालयबाट व्यवस्थापनमा स्नातकोत्तर (एम.बी.ए.) सम्मको उच्च शिक्षा हासिल गरेकी छिन्।\n\nसाहित्यकार प्रसाई बहुमुखी प्रतिभाकी धनी हुन्। उनले कथा, कविता, निबन्ध, उपन्यास, खण्डकाव्य र समीक्षा जस्ता साहित्यका विभिन्न विधामा सफलतापूर्वक कलम चलाएकी छिन्। तथापि, उनी विशेषगरी एक कथाकारका रूपमा परिचित छिन्। उनका सिर्जनाहरूमा नारीवादी चेतना, सामाजिक यथार्थ र मनोवैज्ञानिक विश्लेषण पाइन्छ। जीवन र विज्ञानलाई समन्वय गरेर साहित्य लेख्नु उनको प्रमुख विशेषता हो।\n\nनेपाली साहित्यमा पुऱ्याएको अविस्मरणीय योगदानको कदरस्वरूप उनी **युवावर्ष मोती पुरस्कार**, **मैनाली कथा पुरस्कार**, **राष्ट्रिय प्रतिभा पुरस्कार**, **राष्ट्रिय गौरव युवासम्मान** लगायत थुप्रै पुरस्कार र सम्मानबाट विभूषित भएकी छिन्। भूगोलको सीमाभन्दा माथि उठेर नेपाली साहित्यको विकासमा निरन्तर लागिरहेकी प्रसाई हामी सबैका लागि प्रेरणाको स्रोत हुन्।', 1, '2025-07-25 01:11:38', '2025-09-16 03:05:11'),
(74, 11204, '# यस्तो कहिल्यै नहोस् - कक्षा १० (पूर्ण र विस्तृत गाइड)\r\n\r\n[cite_start]\"यस्तो कहिल्यै नहोस्\" एक मार्मिक र विचारोत्तेजक मनोवाद हो जसले आधुनिक युगको साइबर अपराध र सामाजिक सञ्जालको दुरुपयोगका चुनौती र परिणामहरूलाई गहिरो रूपमा केलाउँछ [cite: 1361, 1362]। [cite_start]यस पाठमा, मुख्य पात्र शुकमानले डिजिटल संसारको जालमा फस्दा आफूले गरेका गल्तीहरू र त्यसबाट उत्पन्न पश्चात्तापलाई आफैँसँग संवाद गर्दै व्यक्त गर्छन् [cite: 1362]। [cite_start]यो विस्तृत गाइडले पाठका मुख्य सन्देश, पाठ, र सबै अभ्यासहरूको गहन र पूर्ण उत्तरहरू समावेश गर्दछ, जसले विद्यार्थीहरूलाई यसको मूल विषयवस्तु बुझ्न र परीक्षाको लागि प्रभावकारी रूपमा तयारी गर्न मद्दत गर्नेछ [cite: 1363]।\r\n\r\n---\r\n\r\n## शब्दभण्डार (Vocabulary)\r\n\r\n### १. दिइएका शब्दको अर्थ लेख्नुहोस् :\r\n\r\n| **शब्द** | **अर्थ** |\r\n| :--- | :--- |\r\n| सङ्कट | [cite_start]आपत्विपत् [cite: 1374] |\r\n| विलाप | [cite_start]बिलौना [cite: 1375] |\r\n| लोहोरो | [cite_start]सिलौटामा मसला आदि पिँध्न प्रयोग गरिने फलाम वा ढुङ्गाको लाम्चो वा गोलो उपकरण [cite: 1377] |\r\n| शङ्का | [cite_start]सन्देह [cite: 1378] |\r\n| अपरिचित | [cite_start]चिनजान नभएको [cite: 1379] |\r\n| सातो | [cite_start]होस [cite: 1380] |\r\n\r\n### २. दिइएको अनुच्छेदबाट तीन-तीनओटा लघुतावाची र समूहवाची शब्द पहिचान गर्नुहोस् :\r\n[cite_start]**अनुच्छेद:** कमिलाको ताँती मौरीको घारमा पसेको देखेर कागको बथान कराउँदै आयो [cite: 1382]। [cite_start]काग कराउँदा कागका मुखमा रहेको भातको सितो खस्यो [cite: 1382]। [cite_start]बाँदर केराको कोसो मुखमा च्यापेर रुखमा चढ्यो [cite: 1383]। [cite_start]बाँदर चढेको देखेर कागको बथान उड्यो [cite: 1383]। [cite_start]बाँदर त्यहाँबाट कुदेर बाँसघारीतिर गयो [cite: 1384]। [cite_start]रुखबाट उडेको तिर्खाएको कागले पानीको थोपो पनि खान पाएन कमिलाले भने चिनीका दानाभन्दा महका थोपा मिठो मानी खाए [cite: 1384]।\r\n\r\n**उत्तर :**\r\n* [cite_start]**लघुतावाची शब्द:** सितो, कोसो, थोपो, दाना [cite: 1386]।\r\n* [cite_start]**समूहवाची शब्द:** ताँती, घार, बथान, घारी [cite: 1386]।\r\n\r\n### ३. पाँच-पाँचओटा लघुतावाची र समूहवाची शब्द पर्ने गरी अनुच्छेद लेख्नुहोस्ः\r\n**वनभोज**\r\n[cite_start]बिहानै एक टुक्रा स्याउ खाएर म वनभोज गएँ [cite: 1389]। [cite_start]बाटोमा गाडीहरू ताँती लगाएर हिँडेका थिए [cite: 1389]। [cite_start]वनभोज स्थलमा मान्छेहरूको भिड थियो [cite: 1389]। [cite_start]एक हुल मान्छेहरू नाचिरहेका थिए [cite: 1390]। [cite_start]त्यहाँ बाँदरको बथान पनि थियो [cite: 1390]। [cite_start]मैले बाँदरलाई एक कोसो केरा दिएँ [cite: 1390]। [cite_start]साथीले कुकुरलाई एक चोक्टो मासु दियो [cite: 1391]। [cite_start]त्यहाँ एउटा रुखमा अरिङ्गालको गोलो पनि देख्यौँ [cite: 1392]। [cite_start]मैले त्यहाँ एक त्यान्द्रो साग र एक पित्को अचार पनि खाएँ [cite: 1392]।\r\n\r\n### ४. दिइएका पद, पदावलीलाई अर्थ खुल्ने गरी वाक्यमा प्रयोग गर्नुहोस् :\r\n* **हरे !:** हरे ! [cite_start]पहिरोले गाउँ नै बगायो [cite: 1394]।\r\n* [cite_start]**सञ्जाल:** नेपालमा धेरै मानिसले सामाजिक सञ्जाल चलाउँछन् [cite: 1395]।\r\n* [cite_start]**विवरण:** मैले मेरो दसैंको खर्च विवरण बाबालाई सुनाएँ [cite: 1396]।\r\n* [cite_start]**सुइँकुच्चा ठोक्नु:** चोरले सामान चोरेर राति नै सुइँकुच्चा ठोकेछ [cite: 1397]।\r\n* [cite_start]**हुने हार दैव नटार:** हुने हार दैव नटार भनेझै सबैले एक दिन यो संसार छोडेर जानैपर्छ [cite: 1398]।\r\n* [cite_start]**लोभले लाभ लाभले विलाप:** चिट्ठा भरेर धेरै कमाउँछु भन्दा साथमा भएको पैसा पनि चैट भयो [cite: 1400]। [cite_start]लोभले लाभ लाभले विलाप भनेको यही हो [cite: 1401]।\r\n\r\n---\r\n\r\n## बोध र अभिव्यक्ति (Comprehension and Expression)\r\n\r\n### १. दिइएका शब्दको शुद्ध उच्चारण गर्नुहोस् :\r\n[cite_start]झल्यास्स, गज्जब, शत्रु, खुरुखुरु, बुद्धि, अत्तोपत्तो, पन्जा, दूरसञ्चार, आश्वस्त [cite: 1407]।\r\n\r\n### २. [cite_start]\'यस्तो कहिल्यै नहोस्\' मनोवाद हाउभाउसहित सस्वरवाचन गर्नुहोस् [cite: 1408]।\r\n\r\n### ३. दिइएका प्रश्नको उत्तर भन्नुहोस् :\r\n* **(क) \'यस्तो कहिल्यै नहोस्\' मनोवाद कुन पात्रको घटनासँग सम्बन्धित छ ?**\r\n    [cite_start]**उत्तर :** \'यस्तो कहिल्यै नहोस्\' मनोवाद शुकमान पात्रको घटनासँग सम्बन्धित छ [cite: 1411]।\r\n* **(ख) मनोवादमा \'नगद पुरस्कारसहित बधाई दिएको सन्देश\' भन्दा अगाडि र पछाडि कुन-कुन प्रसङ्ग आएका छन् ?**\r\n    [cite_start]**उत्तर :** मनोवादमा \'नगद पुरस्कारसहित बधाई दिएको सन्देश\' भन्दा अगाडि र पछाडि सामाजिक सञ्जाल र साइबर अपराधका प्रसङ्ग आएका छन् [cite: 1413]।\r\n* **(ग) पत्रिका मनमनै पढेको वर्णन मनोवादको कुन अनुच्छेदमा छ ?**\r\n    [cite_start]**उत्तर :** पत्रिका मनमनै पढेको वर्णन मनोवादको पाँचौं अनुच्छेदमा छ [cite: 1415]।\r\n* **(घ) मनोवादमा कुन पुरुषीय कथनशैली उपयोग गरिएको छ ?**\r\n    [cite_start]**उत्तर :** मनोवादमा प्रथम पुरुषीय कथनशैली उपयोग गरिएको छ [cite: 1416]।\r\n\r\n### ४. दिइएको मनोवादको अंश पढी सोधिएका प्रश्नको उत्तर दिनुहोस् :\r\n**मनोवादको अंश:** लौ हेर त, १२ पो बजिसकेछ ! (घडी हेर्दै) [cite_start]अब त निदाउनुपर्यो [cite: 1418]। [cite_start]\'हुने हार दैव नटार\' भन्छन् [cite: 1418]। [cite_start]पाँच लाख डुब्यो भनेर अब मैले त्यसैमा चिन्ता लिएर मेरो ज्यान सुकाउनुभन्दा आत्मविश्वासका ऊर्जाले ज्यान बचाउनतिर लाग्नुपर्छ [cite: 1419]। दुई वर्ष अरबको खाडीमा बसेर कमाएको धन गोलखाडीमा गयो त के गर्ने ? [cite_start]आफ्नै बुद्धिले गयो [cite: 1420]। [cite_start]मरुभूमिमा पसिना बगाएर कमाएको त्यो मेरो धन झुक्याएर लाने त्यस्ता दुष्टलाई भगवान्ले पनि सजाय त देलान नि ! [cite: 1421] हे भगवान् ! (अलि ढुक्क हुँदै निदाउनका लागि आँखा चिम्म गर्छन्) [cite_start]खै भगवान्ले पनि के गर्नु र आफ्नै बुद्धि बिग्रेपछि [cite: 1422]। [cite_start]... अँ, अस्ति एउटा समाचार पढेको थिएँ [cite: 1423]। [cite_start]साइबर अपराधका बारेमा लेखेको थियो [cite: 1424]। [cite_start]\'कोही जानी नजानी यस्तो संसारमा पसेका छन्, फसेका छन्, त्यसबाट उम्किने उपाय खोज्छन् र त्यस्तामा अरू पनि कोही नफसोस् भन्ने चाहन्छन् भने नेपाल प्रहरीको साइबर अपराध शाखामा तुरुन्त सम्पर्क गर्नू\' भनी त्यसमा पनि लेखेको थियो [cite: 1424]। (अलि आश्वस्त हुँदै) [cite_start]म त फसें फसें, मेरो पैसा त डुब्यो डुब्यो ! [cite: 1425] [cite_start]अब अरू कोही पनि नफसुन् र नडुबुन् भन्नका लागि अब साइबर अपराध शाखामा जान्छु [cite: 1426]।\r\n\r\n* **(क) मनोवादको अंशमा पात्र निदाउन नसक्नुको कारण के हो ?**\r\n    [cite_start]**उत्तर :** दुई वर्ष अरबको खाडीमा बसेर कमाएको पाँच लाख डुबेको चिन्ताले पात्र निदाउन नसकेका होलान् [cite: 1428]।\r\n* **(ख) पात्रले कहाँ गएर धन कमाएको थियो ?**\r\n    [cite_start]**उत्तर :** पात्रले अरबको खाडीमा गएर धन कमाएको थियो [cite: 1431]।\r\n* **(ग) पात्रले समाचारमा के कुरा पढेको थियो ?**\r\n    [cite_start]**उत्तर :** पात्रले समाचारमा साइबर अपराधका बारेमा पढेको थियो [cite: 1433]।\r\n* **(घ) पात्रले समाचारमा पढेको कुरा व्यवहारमा उतार्न नसक्दा कस्ता समस्या भोग्नुपर्यो, लेख्नुहोस् ।**\r\n    [cite_start]**उत्तर :** पात्रले समाचारमा पढेका कुरा व्यवहारमा उतार्न नसक्दा आफूसँग भएको पैसा गुमाउनुपर्यो [cite: 1442]।\r\n\r\n### ५. \'यस्तो कहिल्यै नहोस्\' मनोवादका पात्रले मनमा खेलाएका मुख्य मुख्य घटना टिपोट गर्नुहोस् ।\r\n**उत्तर :** \'यस्तो कहिल्यै नहोस्\' मनोवादका पात्रले मनमा खेलाएका मुख्य मुख्य घटनाहरुः\r\n* [cite_start]सामाजिक सञ्जालले गर्दा जीवन जटिल बन्नु र समस्यामा फस्नु[cite: 1445],\r\n* [cite_start]मोबाइलभित्रको साइबर संसारमा पस्दा विचार नपुऱ्याएकामा चिन्ता लाग्नु[cite: 1446],\r\n* [cite_start]सामाजिक सञ्जाल प्रयोग र साइबर सचेतनासम्बन्धी कक्षामा सहभागी भएर पनि व्यवहारमा लागू गर्न नसक्दा पछुतो मान्नु[cite: 1447],\r\n* [cite_start]सामाजिक सञ्जालको दुरुपयोगले निम्त्याएका समस्या सम्झनु[cite: 1448],\r\n* [cite_start]मोबाइलका राम्रा र नराम्रा पक्ष सम्झनु[cite: 1449],\r\n* [cite_start]२५ लाख पाउने लोभमा फसेकोमा पछुतो हुनु[cite: 1450],\r\n* [cite_start]काकाकी छोरी पानमती झुटो जालमा परेको सम्झनु[cite: 1451],\r\n* [cite_start]दुई वर्ष अरबको खाडीमा बसेर कमाएको धन गोलखाडीमा जाँदा राति निदाउन नसक्नु[cite: 1452],\r\n* [cite_start]साइबर अपराधको सिकारबाट जोगिने उपाय सम्झनु[cite: 1453],\r\n* [cite_start]कसैलाई साइबर अपराधको सिकार बन्नु नपरोस् भन्ने इच्छा मनमा आउनु [cite: 1454]।\r\n\r\n### ६. \'यस्तो कहिल्यै नहोस्\' मनोवादबाट कस्तो सन्देश पाइन्छ, लेख्नुहोस् ।\r\n[cite_start]**उत्तर :** \'यस्तो कहिल्यै नहोस्\' मनोवादले सामाजिक सञ्जालको प्रयोगमा सचेत बनाउन र साइबर अपराधबारे सिकाउन खोजेको छ [cite: 1458]। [cite_start]यसले मोबाइल र इन्टरनेट जस्ता प्रविधिको सही प्रयोगले जीवन सहज हुने तर दुरुपयोगले ठुला समस्यामा पार्न सक्ने कुरालाई जोड दिएको छ [cite: 1459]। यसबाट पाइने मुख्य सन्देशहरू हुन्:\r\n* [cite_start]आफ्नो कम्प्युटर, ल्यापटप र मोबाइलमा चलाइने सामाजिक सञ्जालका पासवर्ड कसैलाई दिनुहुँदैन [cite: 1460]।\r\n* [cite_start]समय-समयमा पासवर्ड परिवर्तन गरिरहनुपर्छ [cite: 1461]।\r\n* [cite_start]अपरिचित व्यक्ति वा संस्थाबाट आएका इमेल खोल्नुहुँदैन [cite: 1461]।\r\n* [cite_start]इमेलमा काम गरिसकेपछि साइन आउट वा लग आउट गर्नुपर्छ [cite: 1462]।\r\n* [cite_start]इमेल तथा सामाजिक सञ्जालमा आउन सक्ने आकर्षक उपहार वा चिट्ठाको भ्रममा पर्नुहुँदैन [cite: 1463]।\r\n* [cite_start]यस्ता इमेल तथा म्यासेजमाथि शङ्का लागेमा नजिकको प्रहरी कार्यालयमा सम्पर्क गर्नुपर्छ [cite: 1464]।\r\n\r\n### ७. मनोवादमा उल्लेख भएको साइबर अपराधको प्रसङ्ग पढेपछि तपाईंले कस्तो महसुस गर्नुभयो, उल्लेख गर्नुहोस् ।\r\n[cite_start]**उत्तर :** \'यस्तो कहिल्यै नहोस्\' मनोवादमा उल्लेख भएको साइबर अपराधको प्रसङ्ग पढेपछि मलाई सामाजिक सञ्जालको प्रयोगमा सचेत बन्नुपर्ने चेतना अझ बढ्यो [cite: 1466]। [cite_start]पात्र शुकमान र यस्तै ठगीका घटनाहरु मेरो स्मरणमा आए [cite: 1467]। [cite_start]शुकमानले जस्तै यस विषयमा ज्ञान भएर पनि बेवास्ता गर्ने बानी थियो तर यस पाठले सम्भावित घटनाप्रति अझ सचेत बनायो [cite: 1469]। [cite_start]सामाजिक सञ्जालका माध्यमबाट हुन सक्ने साइबर अपराधबाट बच्ने थप उपायहरुको ज्ञान पनि भयो [cite: 1470]।\r\n\r\n---\r\n\r\n## सिर्जना र परियोजना कार्य (Creative and Project Work)\r\n\r\n### १. एसईई परीक्षाको नतिजा प्रकाशन हुनुभन्दा अघिल्लो दिनको मनोदशा समेटेर छोटो मनोवाद लेख्नुहोस्।\r\n[cite_start]**पात्र:** सुमित [cite: 1475]\r\n[cite_start]**स्थान:** सुत्ने कोठा [cite: 1476]\r\n[cite_start]**समय:** राति १०:०० बजे [cite: 1477]\r\n\r\n[cite_start](भोलि एसईई परीक्षाको नतिजा प्रकाशन हुँदै छ [cite: 1479]। [cite_start]ऊ आफ्‌नो बिछ्यौनामा पल्टिइरहेको छ [cite: 1479]। [cite_start]सुमित परीक्षाको नतिजा आउने खबरले बेचैन छ [cite: 1479]। [cite_start]नतिजा र अब के पढ्ने भन्ने भविष्यको चिन्ताले छटपटाएको पनि छ [cite: 1479]। [cite_start]उसको मनमा विभिन्न कुराहरु खेलिरहेका छन् [cite: 1479]।)\r\n\r\nला ! [cite_start]नतिजा आउने दिन पनि आइहाल्यो [cite: 1480]। [cite_start]नतिजा राम्रो आए त केही चिन्ता थिएन, नतिजा राम्रो आएन भने त ढुक्कै हो, मेरो बाबाले मलाई खाडी पठाउनुहुन्छ [cite: 1480]। [cite_start]परीक्षाको तयारीका लागि भनेर ट्युसन, कोचिङ सबै पढियो [cite: 1481]। [cite_start]बिहान ५ बजेदेखि बेलुका १० बजेसम्म [cite: 1481]। [cite_start]हैट, यति पढेर परीक्षा दिँदा पनि पास नभए त कहिल्यै नपढे पनि भो [cite: 1482]। [cite_start](पानी पिउँछ [cite: 1482]।) ह्या! [cite_start]कति चिन्ता लिएको मैले पनि यतिको लेख्दा ए+ नआए पनि बि सम्म त कसो नआउला र ! [cite: 1483] [cite_start]बाबाले छोरोले ए+ ल्याउँछ भन्ने आशा गर्नुभएको छ होला, ए+ आएन भने बाबा त पक्कै दुःखी हुनुहुने छ [cite: 1484]। [cite_start]छोराछोरीको राम्रो नतिजाका लागि आशा गर्नु नराम्रो पनि त होइन [cite: 1485]। [cite_start](पर्दा खोलेर बाहिर हेर्छ [cite: 1486][cite_start]।) भोलि यतिबेला त नतिजा आइसक्छ [cite: 1486]। [cite_start]अबको बाटो के हुने भन्ने पनि यही ग्रेडले निर्धारण गर्ने होला [cite: 1487]। [cite_start]ए+ आए विज्ञान विषय नै पढ्नुपर्ने होला नत्र व्यवस्थापन पढ्ने त होला [cite: 1488]। [cite_start]हुनत यो नतिजा मात्र पनि त सबथोक होइन भो [cite: 1489]। [cite_start]फलामे ढोका भन्दै धेरै हाउगुजी ठानेर पनि यस्तो भएको हो [cite: 1489]। [cite_start](मनलाई सम्हाल्न खोज्छ [cite: 1490][cite_start]।) एसईईमा राम्रो ग्रेड आएर पछि गुल्टिन र सोचेजस्तो नआएर पछि राम्रो हुन पनि त सक्छ नि [cite: 1490]। [cite_start]एउटा कक्षाको परीक्षा त हो, यसलाई यत्रो हाउगुजी किन ठानेको हुँला ! [cite: 1490] [cite_start]सोचे जस्तो नआए मिहिनेत कम भएछ, अर्को कक्षामा अझ मिहिनेत गर्नुपर्छ भनेर बुझुँला [cite: 1490]। [cite_start]जिन्दगीले झन् कस्ता कठिन परीक्षा लिने हो [cite: 1490]। [cite_start]निराश भएर हरेस खानु नपरोस् अरु त्यस्तै हो [cite: 1490]। [cite_start](घडी हेर्छ [cite: 1490][cite_start]) ए ढिला भइसकेछ, सुत्नुपर्यो [cite: 1490]। [cite_start](बत्ती निभाएर सुत्छ [cite: 1490]।)\r\n\r\n### २. पुरस्कृत हुँदाको क्षण समेटेर छोटो मनोवाद लेख्नुहोस्।\r\n[cite_start]**पात्र:** सुशान्त [cite: 1492] (Source uses \'सुमित\' for the previous, \'सुशान्त\' for this monologue)\r\n[cite_start]**स्थान:** सुत्ने कोठा [cite: 1492]\r\n[cite_start]**समय:** राति १०:०० बजे [cite: 1493]\r\n\r\n[cite_start](सुशान्त आज खुसी छ [cite: 1494]। [cite_start]उसको अनुहारमा बेग्लै चमक देखिन्छ [cite: 1494]। [cite_start]कोठाको भित्तामा झुन्डिएको प्रमाणपत्र हेरेर आनन्दले रमाउँदै छ किनकि जिल्लास्तरीय वादविवाद प्रतियोगितामा प्रथम भएको छ र उसको मनमा विभिन्न कुराहरु खेलिरहेका छन् [cite: 1494]।)\r\n\r\n(मनमनै) धन्य भगवान् ! (हात जोडी प्रतियोगिताका क्षण सम्झदै) [cite_start]मिहिनेत गरे त्यसको फल एक दिन अवश्य पाइने नै रहेछ [cite: 1496]। [cite_start]सानो भए (पनि मेरो एउटा सपना पूरा भएको छ [cite: 1497]। [cite_start]यत्रो एकसे एक जान्ने विद्यार्थीहरु हुँदाहुँदै जिल्लास्तरीय प्रतियोगितामा प्रथम हुनु चानचुने कुरा पनि त होइन नि [cite: 1497]। [cite_start]उद्घोषकले तेस्रो र दोस्रो हुनेको नाम भनिसक्दा म प्रथम हुने आशा मरिसकेको थियो [cite: 1497]। प्रथम हुनेमा मेरो नाम भन्दा म त झण्डै उफ्रिएको ! (खुसी हुँदै) [cite_start]त्यो तालीको गडगडाहट र त्यतिबेला मेरो नेपाली विषय शिक्षकको मुहार पनि हेर्न लायक थियो [cite: 1497]। [cite_start]त्यहाँ उपस्थित ठूला ठूला मान्छेहरुले बधाई दिँदा त मलाई कस्तो लाज लागेको थियो [cite: 1497]। [cite_start]आमालाई यो कुरा सुनाउँदा आमाले हर्षका आँसु झार्नु भो [cite: 1504]। [cite_start]मलाई बल्ल थाहा भयो छोराछोरीको खुसीमा आमाबाबा कति खुसी बन्दा रहेछन् भनेर [cite: 1504]। [cite_start]एकपल्ट त त्यति धेरै मान्छेको सामुन्ने गएर कसरी बोल्ने होला भन्ने चिन्ता पनि बढ्यो [cite: 1506]। [cite_start]डरले मुटु ढुक्क पनि भयो [cite: 1506]। [cite_start]...मैले मिहिनेत कम गरेको पनि त होइन नि [cite: 1510]। [cite_start]गुगलमा खोजेर र युटुबमा हेरेर तयारी गरेको फाइदै भयो [cite: 1510]। (मुस्कुराउँदै) [cite_start]अब त सबैको सामुन्ने छाती फुलाएर हिँड्न पाइन्छ [cite: 1512]। (कोल्टे फेर्दै) [cite_start]यसमा मेरा गुरु, आमाबाबा र साथीहरुको पनि ठूलो योगदान छ [cite: 1513]। [cite_start]मैले अझ मेरो प्रतिभालाई तिखार्नुपर्छ [cite: 1513]। (सुत्न खोज्दै) [cite_start]अब भोलि स्कुल जाँदा मिठाई लगेर गुरु र साथीहरुलाई दिनुपर्छ [cite: 1515]।\r\n\r\n### ३. दिइएको विज्ञापनको नमुना पढी आफ्नो विद्यालयको बालसाहित्य पत्रिकाका लागि विज्ञापन तयार गर्नुहोस्ः\r\n**बाल पत्रिका \'आँकुरा\' प्रकाशनसम्बन्धी सूचना**\r\n[cite_start]विद्यार्थीहरुमा लुकेर रहेको प्रतिभालाई उजागर गर्ने उद्देश्यले हाम्रो यस रत्न राज्य माध्यमिक विद्यालयमा बालपत्रिका \'आँकुरा\' प्रकाशन हुन लागेको सहर्ष जानकारी गराउँछौँ [cite: 1542]। [cite_start]बालसाहित्यको क्षेत्रमा प्रकाशन हुन गइरहेको यस पत्रिकामा आगामी अङ्कका लागि आफ्‌ना रचनाहरु पठाउनका लागि लेखन, कला र साहित्यप्रति रुचि राख्ने कक्षा १२ सम्म अध्ययन गर्ने सम्पूर्ण विद्यार्थीहरुलाई आह्वान गरिन्छ [cite: 1543]।\r\n[cite_start]**पुनश्चः** उत्कृष्ट रचनाहरुलाई पुरस्कारको व्यवस्था पनि गरिएको छ [cite: 1544]।\r\n[cite_start]**रचना पठाउने ठेगानाः** रत्न राज्य माध्यमिक विद्यालय, विकासनगर-४, कैलाली [cite: 1544]\r\n[cite_start]**मितिः** २०८० जेठ १० गतेसम्म [cite: 1544]\r\n\r\n### ४. अनुच्छेद पढी सोधिएका प्रश्नको उत्तर दिनुहोस् :\r\n* **(अ) प्रविधिको प्रयोगले सिकाइमा कस्तो सुविधा पुऱ्याएको छ ?**\r\n    [cite_start]**उत्तर :** प्रविधिको प्रयोगले सिकाइ प्रणालीलाई सरल, प्रायोगिक, मनोरञ्जक र चिरस्थायी बनाउन सहयोग पुऱ्याएको छ [cite: 1545, 1558]।\r\n* **(आ) तपाईंले सिकाइका लागि कुन कुन एप्स प्रयोग गर्नुभएको छ, नाम लेख्नुहोस् ।**\r\n    [cite_start]**उत्तर :** मैले सिकाइका लागि गुगल, युटुब जस्ता एप्स प्रयोग गरेको छु [cite: 1560]।\r\n* **(इ) विद्यार्थीमा प्रविधिप्रति मोह बढ्नुको कारण के हो ?**\r\n    [cite_start]**उत्तर :** सिकाइ रुचिपूर्ण र चाखलाग्दो हुनुका साथै विद्यार्थीले इमेल, इन्टरनेट आदिको प्रयोगबाट नयाँ नयाँ विषयवस्तु खोजेर आफै सिक्न सक्ने भएकाले विद्यार्थीमा प्रविधिप्रति मोह बढेको हो [cite: 1562]।\r\n* **(ई) विद्यार्थीलाई परियोजना कार्य गर्न प्रविधिले कसरी सहयोग गर्छ ?**\r\n    [cite_start]**उत्तर :** प्रविधि प्रयोगबाट विद्यार्थीले इन्टरनेट तथा अन्य क्षेत्रबाट नयाँ नयाँ विषयवस्तु खोजेर अनुसन्धान र खोजका साथ परियोजना कार्य गर्न सक्छन् [cite: 1548, 1564]।\r\n\r\n### ५. भाषिक संरचना र वर्णविन्यास पहिचान गर्नुहोस्ः\r\n* **(अ) अनुच्छेदबाट दुईओटा समस्त शब्द खोजी तिनको विग्रह गर्नुहोस् ।**\r\n    [cite_start]**उत्तर :** कक्षाकोठा (कक्षाका लागि कोठा), चौघेरा (चार घेराको समूह) [cite: 1572]।\r\n* **(आ) \'ठुलो\' र \'पढाइ\' शब्दलाई द्वित्व प्रक्रियाबाट नयाँ शब्द बनाउनुहोस् ।**\r\n    [cite_start]**उत्तर :** ठुल्ठुलो, पढाइसढाइ [cite: 1573]।\r\n* **(इ) अनुच्छेदबाट सुरु र बिचमा दीर्घ ऊकार प्रयोग भएका एक-एक ओटा शब्द टिप्नुहोस् ।**\r\n    **उत्तर :** सुरुमा: (पाठ्यक्रममा \'पूर्ण\' शब्द छैन, तर उदाहरणका लागि) पूर्ण; [cite_start]बिचमा: खोजमूलक [cite: 1575, 1576]।\r\n\r\n---\r\n\r\n## भाषिक संरचना र वर्णविन्यास (Linguistic Structure and Spelling)\r\n\r\n### १. दिइएको अनुच्छेदबाट तीनओटा समस्त शब्द र तीनओटा विग्रह पदावली पहिचान गरी लेख्नुहोस्ः\r\n**उत्तर :**\r\n* [cite_start]**समस्त शब्द:** दिनरात (दिन र रात), रुनु न हाँस्नु (न रुनु न हाँस्नु), जेठोबाठो (जेठो पनि बाठो पनि) [cite: 1583]।\r\n* [cite_start]**विग्रह पदावली:** आपत् र विपत् (आपत्विपत्), गृहकी लक्ष्मी (गृहलक्ष्मी), इन्तु न चिन्तु (इन्तुचिन्तु) [cite: 1581, 1583]।\r\n\r\n### २. \'यस्तो कहिल्यै नहोस्\' मनोवादबाट पाँचओटा समस्त शब्द पहिचान गरी तिनको विग्रह गर्नुहोस् ।\r\n[cite_start]**उत्तर :** समस्याग्रस्त (समस्याले ग्रस्त), साइबर अपराध (साइबरसम्बन्धी अपराध), लोककथा (लोकको कथा), दिदीबहिनी (दिदी र बहिनी), देशविदेश (देश र विदेश) [cite: 1585]।\r\n\r\n### ३. दिइएका समस्त शब्दको विग्रह गर्नुहोस् :\r\n* [cite_start]**प्रतिदिन:** प्रत्येक दिन [cite: 1587]\r\n* [cite_start]**भरपेट:** पेट भर [cite: 1588]\r\n* [cite_start]**पकेटमार:** पकेट मार्ने [cite: 1589]\r\n* [cite_start]**कलाप्रवीण:** कलामा प्रवीण छ जो [cite: 1590]\r\n* [cite_start]**चरणकमल:** चरणरुपी कमल [cite: 1590]\r\n* [cite_start]**जेठोबाठो:** जेठो पनि बाठो पनि [cite: 1590]\r\n* [cite_start]**नवरत्न:** नौ रत्नको समूह [cite: 1591]\r\n* [cite_start]**राधाकृष्ण:** राधा र कृष्ण [cite: 1598]\r\n* [cite_start]**लाम्खुट्टे:** लामा खुट्टा भएको [cite: 1598]\r\n* [cite_start]**सप्तर्षि:** सात ऋषिको समूह [cite: 1598]\r\n\r\n### ४. दिइएको अनुच्छेदबाट शब्दको सुरु, बिच र अन्तिममा दीर्घ ऊकार प्रयोग भएका शब्द पहिचान गर्नुहोस् :\r\n**उत्तरः**\r\n* [cite_start]**सुरुमा दीर्घ ऊकार:** पूर्णबहादुर, ऊष्ण [cite: 1615]\r\n* [cite_start]**बिचमा दीर्घ ऊकार:** मयूर, फलफूल, विभूषण, विद्याभूषण [cite: 1616]\r\n* [cite_start]**अन्तिममा दीर्घ ऊकार:** बधू [cite: 1617]\r\n\r\n### ५. दुई जना साथीबिच पढाइका बारेमा भएको संवाद लेख्नुहोस् ।\r\n[cite_start]**(अस्मिता र श्रेया कालिका स्कुलको कक्षा १० मा पढ्ने छात्राहरु हुन् [cite: 1632]। [cite_start]विद्यालयको खाजा खाने समयमा दुई जना चौरको छेउमा बसेर खाजा खाँदै आफ्‌नो पढाइका बारेमा कुराकानी गर्दै छन् [cite: 1632]।)\r\n[cite_start]**अस्मिताः** सुन न श्रेया, मलाई त अचेल पढाइतिर ध्यानै जान छाड्यो [cite: 1633]।\r\n**श्रेयाः** होइन के भो र फेरि ? [cite_start]कसैको मायामा पर्यो कि क्या हो ? [cite: 1634]\r\n[cite_start]**अस्मिताः** ह्या, यिनलाई फेरि जतिबेला पनि मजाक मात्र गर्नुपर्ने [cite: 1635]। [cite_start]जति पढे पनि दिमागमा घुस्दै घुस्दैन क्या ! [cite: 1635]\r\n[cite_start]**श्रेयाः** पढाइ सजिलो त कहाँ छ र ? [cite: 1636] [cite_start]अध्ययनका क्रममा कहिलेकाहीँ यस्तो विचार आउनु सामान्य हो [cite: 1636]। [cite_start]केही विषयवस्तु बुझ्नलाई अलिकति कठिन हुँदैमा निराश हुनु त भएन नि [cite: 1637]।\r\n[cite_start]**अस्मिताः** यस्तो दुःख गरेर पढ्यो अनि पछि जागिर पनि पाइँदैन [cite: 1638]। [cite_start]बिहे गरेर लोग्नेको घरमा गृहिणी भएर बस्नुपर्ने होला [cite: 1638]।\r\n[cite_start]**श्रेयाः** फेरि यस्तै कुरा, तिमी जस्तो मान्छेले पनि यस्तो कुरा गर्न सुहाउँछ ? [cite: 1639] [cite_start]राम्रोसँग पढेर आत्मनिर्भर बन्नुपर्छ [cite: 1639]। [cite_start]महिलाहरु पढेर कहाँ कहाँ पुगिसके, यिनको दिमाग भने अझै पन्ध्रौं शताब्दीमै छ [cite: 1640]। [cite_start]फेरि पढ्ने जागिर खान मात्र पनि त होइन [cite: 1641]।\r\n[cite_start]**अस्मिताः** उसो भए भन न त पढेर के गर्ने ? [cite: 1642]\r\n[cite_start]**श्रेयाः** पढेपछि जीवन सहज हुन्छ [cite: 1643]। [cite_start]दैनिक समस्याहरु पनि सही किसिमले समाधान गर्न सकिन्छ [cite: 1644]। [cite_start]सही समयमा सही निर्णय लिने क्षमता विकास हुन्छ [cite: 1644]। [cite_start]सबैभन्दा ठुलो कुरा त पढाइले हामीलाई आत्मनिर्भर बनाउँछ [cite: 1645]।\r\n[cite_start]**अस्मिताः** त्यो त हो [cite: 1646]। [cite_start]अब राम्रोसँग पढ्‌नुपर्छ [cite: 1646]। [cite_start]तिमी पनि सिकाऊ है [cite: 1646]।\r\n[cite_start]**श्रेयाः** भइहाल्छ नि [cite: 1647]। [cite_start](घण्टी बज्छ [cite: 1647]। [cite_start]दुवै कक्षाकोठातिर जान्छन् [cite: 1647]।)', 1, '2025-07-25 01:11:38', '2025-09-16 03:05:11');
INSERT INTO `course_notes_content` (`id`, `topic_id`, `content`, `markdown_format`, `created_at`, `updated_at`) VALUES
(75, 11209, '# मेरो देशको शिक्षा - कक्षा १० (पूर्ण विस्तृत गाइड)\r\n\r\n\"मेरो देशको शिक्षा\" निबन्धले हाम्रो देशको शिक्षा प्रणालीको वर्तमान अवस्था, चुनौती र भविष्यको सम्भावनालाई केलाउँछ। यसले शिक्षाले राष्ट्रको भविष्यलाई कसरी आकार दिन्छ भन्ने कुरामा प्रकाश पार्दै पाठ्यक्रम, शिक्षण विधि र शैक्षिक नीतिहरूका विभिन्न पक्षहरूको अन्वेषण गर्दछ। यो विस्तृत गाइडले परीक्षाको तयारीका लागि सबै प्रश्नहरूको गहन र पूर्ण उत्तरहरू समावेश गर्दछ।\r\n\r\n---\r\n\r\n## शब्दभण्डार (Vocabulary)\r\n\r\n### १. दिइएका अर्थ बुझाउने शब्द र जोडा मिलाउनुहोस् :\r\n\r\n| **शब्द** | **अर्थ** |\r\n| :--- | :--- |\r\n| आविष्कार | नयाँ कुराको खोजी |\r\n| समालोचना | खास विषयको गुण, दोष आदिको मूल्याङ्कन |\r\n| व्यवसाय | जीवन निर्वाहका लागि गरिने काम |\r\n| ग्रन्थ | महत्त्वपूर्ण मानिएका ठूला आकारका पठनीय सामग्री |\r\n| शिष्टाचार | शिष्ट या सभ्य मानिसको आचरण |\r\n| मुहान | उद्गमस्थल |\r\n| तीर्थाटन | तीर्थयात्रा |\r\n| पसिना | परिश्रम गर्दा शरीरबाट निस्कने पानी |\r\n| मार्ग | बाटो |\r\n| त्रुटि | गल्ती |\r\n| खानी | धेरै चिज उत्पन्न भएको ठाउँ |\r\n| पुरातन | प्राचीन |\r\n\r\n### २. अनुच्छेदबाट प्राविधिक तथा पारिभाषिक शब्दहरू पहिचान गर्नुहोस् :\r\n**अनुच्छेद:** शिक्षण सिकाइको महत्त्वपूर्ण पक्ष शिक्षक हो। शिक्षकले पाठ्यक्रमअनुसार विषयवस्तुमा आधारित भएर शिक्षण गर्नु अपरिहार्य हुन्छ। शिक्षणलाई प्रभावकारी बनाउन पाठयोजना बनाउनसमेत अनिवार्य हुन्छ। पाठयोजनाभित्र विशिष्ट उद्देश्य, पाठ्यवस्तु, शैक्षणिक सामग्री, सिकाइ सहजीकरण क्रियाकलाप, मूल्याङ्कन र गृहकार्य रहन्छन्।\r\n\r\n**उत्तर:** शिक्षण, शिक्षक, पाठ्यक्रम, पाठयोजना, पाठ्यवस्तु, शैक्षणिक, सिकाइ, सहजीकरण, क्रियाकलाप, मूल्याङ्कन र गृहकार्य।\r\n\r\n### ३. पारिभाषिक शब्दहरूलाई वाक्यमा प्रयोग गर्नुहोस् :\r\n* **समालोचनात्मक:** कुनै पनि कुरालाई अन्धविश्वास गर्नुको सट्टा हामी सबैमा **समालोचनात्मक** दृष्टि हुनुपर्छ।\r\n* **विज्ञान:** यो युग **विज्ञान** र प्रविधिको युग हो, त्यसैले वैज्ञानिक शिक्षा अपरिहार्य छ।\r\n* **प्रविधि:** नयाँ **प्रविधि**को विकासले हाम्रो जीवनलाई धेरै सहज बनाएको छ।\r\n* **परिष्कृत:** हामीले समयअनुसार आफ्ना पुराना ज्ञान र सीपलाई **परिष्कृत** गर्दै लैजानुपर्छ।\r\n* **इतिहास:** नेपालको **इतिहास** गौरवपूर्ण छ र यसबाट हामीले धेरै कुरा सिक्न सक्छौँ।\r\n\r\n---\r\n\r\n## बोध र अभिव्यक्ति (Comprehension and Expression)\r\n\r\n### १. दिइएका प्रश्नको उत्तर लेख्नुहोस्ः\r\n\r\n**(क) \'मेरो देशको शिक्षा\' निबन्धमा कस्तो व्यवसायमूलक शिक्षाको अपेक्षा गरिएको छ ?**\r\n**उत्तर:** \'मेरो देशको शिक्षा\' निबन्धमा नेपालको भूगोल र पर्यावरण अनुकूल व्यवसायमूलक शिक्षाको अपेक्षा गरिएको छ। जुन ठाउँमा जे कुराको उत्पादन सम्भव छ, त्यही ठाउँमा त्यसैको उत्पादन, प्रशोधन र बजारीकरणसम्बन्धी शिक्षा दिनुपर्छ भन्ने विचार प्रस्तुत गरिएको छ। हाम्रो परम्परागत ज्ञान र सीपलाई आधुनिक प्रविधिसँग जोडेर अगाडि बढाउने शिक्षा सान्दर्भिक हुने बताइएको छ। कृषिमा अत्याधुनिक औजारको प्रयोग गर्ने, विज्ञान र प्रविधियुक्त सीप सिकाउने र समग्रमा विद्यार्थीलाई स्वरोजगार बनाएर आत्मनिर्भर बनाउन सक्ने शिक्षाको अपेक्षा यस निबन्धमा गरिएको छ।\r\n\r\n**(ख) शिक्षाले मानव जीवनका कुन-कुन कुरामा सुधार ल्याउँछ ?**\r\n**उत्तर:** शिक्षाले मानव जीवनका हरेक पक्षमा सकारात्मक सुधार ल्याउँछ। यसले हरेक काममा सहजता ल्याउँछ, जस्तै मोबाइल एप्सबाट अनलाइन टिकट काट्ने, बैङ्किङ कारोबार गर्ने र घरमै सामान मगाउने जस्ता कामहरू गर्न सकिन्छ। शिक्षाले मानिसमा समालोचनात्मक सोचको विकास गरी नयाँ-नयाँ ज्ञान निर्माण गर्न सक्ने बनाउँछ। यसले मानिसलाई कर्तव्य, दायित्व र सद्गुण जस्ता मानवीय मूल्यहरू सिकाउँछ र सही मार्गमा लाग्न प्रेरित गर्छ। शिक्षाले व्यक्तिमा सकारात्मक गुणहरू भरिदिन्छ, परिवर्तनलाई आत्मसात् गर्न सक्ने बनाउँछ र अन्ततः उसलाई आत्मनिर्भर र विवेकशील नागरिकका रूपमा स्थापित गर्छ।\r\n\r\n**(ग) विज्ञान र प्रविधिमा आधारित शिक्षाको महत्त्व लेख्नुहोस्।**\r\n**उत्तर:** आजको युग सूचना र प्रविधिकको युग भएकोले विज्ञान र प्रविधिमा आधारित शिक्षाको महत्त्व अपार छ। यस्तो शिक्षाले हरेक काममा सहजता र दक्षता ल्याएको छ। मोबाइल एप्सबाट अनलाइन कारोबार गर्नेदेखि घरमै बसेर व्यापार-व्यवसाय सञ्चालन गर्नसमेत प्रविधिले सम्भव बनाएको छ। कृषिजन्य वस्तुको अनलाइन बजारीकरण गरी आयआर्जन बढाउन सकिन्छ। इन्टरनेट सूचना र जानकारीको विशाल स्रोत हो, जसको प्रयोगले विद्यार्थीहरूलाई विश्वव्यापी ज्ञानसँग जोड्न सकिन्छ। विज्ञान र प्रविधियुक्त शिक्षाले विद्यार्थीलाई युगीन आवश्यकता र आविष्कारसँग जोड्दै उनीहरूलाई सम्मान, खुसी र सुखपूर्वक बाँच्न आवश्यक ज्ञान र सीप प्रदान गर्दछ।\r\n\r\n**(घ) निबन्धको मुख्य सन्देश के हो ?**\r\n**उत्तर:** \'मेरो देशको शिक्षा\' निबन्धको मुख्य सन्देश नेपालमा युग सुहाउँदो, वैज्ञानिक, व्यावहारिक एवम् व्यावसायिक शिक्षाको आवश्यकता छ भन्ने हो। निबन्धले हाम्रो शिक्षा प्रणालीलाई देशको भूगोल र पर्यावरण अनुकूल बनाउनुपर्नेमा जोड दिएको छ। सीपयुक्त र व्यवसायमूलक शिक्षाले मात्र विद्यार्थीलाई आत्मनिर्भर बनाउन सक्छ र देशमा रोजगारीका अवसरहरू सिर्जना गर्न सक्छ। हाम्रो शिक्षाले प्राचीन ज्ञान र मान्यतालाई आत्मसात् गर्दै तिनलाई समयानुकूल परिष्कृत गर्दै लैजानुपर्छ। समग्रमा, शिक्षाको माध्यमबाट देशलाई समृद्धितर्फ लैजान सकिन्छ र यसका लागि व्यावसायिक, प्राविधिक र मूल्यमा आधारित शिक्षा प्रणाली लागू गर्नुपर्छ भन्नु नै यस निबन्धको मुख्य सन्देश हो।\r\n\r\n### २. व्याख्या गर्नुहोस्ः\r\n\r\n**(क) आत्मनिर्भरताको लक्ष्य स्वरोजगार बन्नु हो।**\r\n**प्रस्तुत सन्दर्भ:** प्रस्तुत निबन्धांश \'मेरो देशको शिक्षा\' नामक निबन्धबाट साभार गरिएको हो। यस निबन्धमा व्यावसायिक र प्राविधिक शिक्षाको महत्त्वमाथि प्रकाश पार्दै शिक्षाले मानिसलाई आत्मनिर्भर बनाउनुपर्छ भन्ने सन्दर्भमा यो अंश आएको हो।\r\n\r\n**विस्तृत व्याख्या:** शिक्षालाई मानव जातिको तेस्रो आँखा मानिन्छ, जसले ज्ञान र सीप प्रदान गर्दछ। तर, त्यो ज्ञान र सीप तब मात्र सार्थक हुन्छ जब त्यसले व्यक्तिलाई कसैमाथि निर्भर नरही आफ्नै खुट्टामा उभिन सक्षम बनाउँछ। \'आत्मनिर्भरता\' को वास्तविक अर्थ यही हो। र, आत्मनिर्भर बन्ने सबैभन्दा उत्तम मार्ग भनेको \'स्वरोजगार\' हो, अर्थात् आफ्नै लागि रोजगारी सिर्जना गर्नु।\r\n\r\nजब शिक्षालाई सीपसँग, सीपलाई श्रमसँग र श्रमलाई आधुनिक प्रविधिसँग जोडिन्छ, तब व्यक्तिले अरूको जागिर खोज्दै हिँड्नुको सट्टा आफ्नै व्यवसाय सञ्चालन गर्न सक्छ। यस्तो सीपयुक्त शिक्षाले मानिसलाई उद्यमी बन्न उत्प्रेरित गर्छ र आफ्नै देशमा पसिना बगाउने अवसर प्रदान गर्छ। यसरी, शिक्षाको अन्तिम लक्ष्य प्रमाणपत्रको थुप्रो लगाउनु मात्र होइन, बरु व्यक्तिलाई यति सक्षम बनाउनु हो कि उसले आफ्नो र अरूको लागि समेत रोजगारी सिर्जना गर्न सकोस्। त्यसैले, आत्मनिर्भरताको लक्ष्य स्वरोजगार बन्नु हो भनिएको हो।\r\n\r\n**(ख) शिक्षित व्यक्तिमा शिष्टाचार, प्रतिबद्धता, सांस्कृतिक सद्भाव, सामाजिक सद्व्यवहारका क्षमता हुनु जरुरी छ।**\r\n**प्रस्तुत सन्दर्भ:** यो निबन्धांश \'मेरो देशको शिक्षा\' पाठबाट लिइएको हो, जसमा शिक्षाको उद्देश्य केवल प्राविधिक ज्ञान दिनु मात्र नभई मानवीय र नैतिक मूल्यहरूको विकास गर्नु पनि हो भन्ने सन्दर्भमा यो भनाइ आएको हो।\r\n\r\n**विस्तृत व्याख्या:** शिक्षाको अर्थ केवल किताबी ज्ञान वा प्रमाणपत्र हासिल गर्नु मात्र होइन। वास्तविक शिक्षा त्यो हो, जसले मानिसको व्यवहारमा झल्किन्छ र उसलाई एक असल सामाजिक प्राणी बनाउँछ। एक शिक्षित व्यक्तिमा **शिष्टाचार** (अरूप्रति सम्मानजनक व्यवहार), **प्रतिबद्धता** (आफ्नो काम र वचनप्रतिको निष्ठा), **सांस्कृतिक सद्भाव** (आफ्नो र अरूको संस्कृतिप्रति सम्मान) र **सामाजिक सद्व्यवहार** (समाजमा मिल्न सक्ने क्षमता) जस्ता गुणहरू हुनु अनिवार्य छ।\r\n\r\nयदि कक्षा दसमा पढ्ने विद्यार्थीलाई आफूभन्दा ठुलालाई आदर गर्न आउँदैन भने उसको शिक्षाको कुनै अर्थ रहँदैन। शिक्षाले मानिसलाई नैतिकवान, सहिष्णु, विवेकशील र अनुशासित बनाउनुपर्छ। सकारात्मक गुणहरूले भरिपूर्ण व्यक्तिले मात्र समाजमा सकारात्मक योगदान दिन सक्छ। त्यसैले, हाम्रो शिक्षा सैद्धान्तिकभन्दा बढी व्यावहारिक हुनुपर्छ र यसले हामीमा असल बानी र व्यवहारको विकास गर्न सक्नुपर्छ भन्ने गहिरो आशय यस निबन्धांशमा व्यक्त भएको छ।\r\n\r\n### ३. \'मेरो देशको शिक्षा\' निबन्धका आधारमा नेपालको भावी शिक्षा कस्तो हुनुपर्छ, समीक्षात्मक उत्तर लेख्नुहोस्।\r\n**उत्तर:** \'मेरो देशको शिक्षा\' निबन्धले नेपालको भावी शिक्षा कस्तो हुनुपर्छ भन्नेबारे एक स्पष्ट मार्गचित्र प्रस्तुत गरेको छ। यस निबन्धका आधारमा नेपालको भावी शिक्षा प्रणाली निम्न विशेषताहरूले युक्त हुनुपर्छ:\r\n१. **युगानुकूल, विज्ञान र प्रविधियुक्त:** देशको शिक्षा बदलिँदो युगसँगै समायोजन हुन सक्ने, विज्ञान र प्रविधिसँग हातेमालो गर्ने खालको हुनुपर्छ। विद्यार्थीहरूलाई सूचना प्रविधिमा पोख्त र दक्ष बनाउनुपर्छ।\r\n२. **व्यावसायिक र सीपमूलक:** शिक्षालाई सीपसँग, सीपलाई श्रमसँग र श्रमलाई आधुनिक प्रविधिसँग जोड्नुपर्छ। यसले विद्यार्थीलाई स्वरोजगार र आत्मनिर्भर बन्न मद्दत गर्छ, जसले देशमा रोजगारी सिर्जना गर्छ।\r\n३. **भूगोल र पर्यावरण अनुकूल:** नेपालको शिक्षा यहाँको भूगोल र पर्यावरण अनुकूल हुनुपर्छ। हिमाल, पहाड र तराईको विशेषताअनुसार फरक-फरक व्यावसायिक शिक्षाको विकास गर्नुपर्छ।\r\n४. **मौलिकता र आधुनिकताको सङ्गम:** हाम्रो शिक्षाले पूर्वीय ज्ञान, दर्शन र परम्परागत सीपलाई संरक्षण गर्दै पाश्चात्य विज्ञान र प्रविधिलाई पनि आत्मसात् गर्नुपर्छ।\r\n५. **मूल्यमा आधारित:** शिक्षाले केवल दक्ष जनशक्ति मात्र होइन, असल नागरिक पनि उत्पादन गर्नुपर्छ। शिक्षित व्यक्तिमा शिष्टाचार, प्रतिबद्धता, सांस्कृतिक सद्भाव र सामाजिक सद्व्यवहार जस्ता सकारात्मक र नैतिक गुणहरू हुनुपर्छ।\r\n६. **समालोचनात्मक चिन्तनमा आधारित:** शिक्षाले विद्यार्थीमा रटेर पास हुने प्रवृत्तिलाई निरुत्साहित गर्दै हरेक कुरालाई तर्क, विवेक र विश्लेषणका आधारमा हेर्ने समालोचनात्मक सोचको विकास गर्नुपर्छ।\r\nसमग्रमा, नेपालको भावी शिक्षा आफ्नो मौलिकतासहितको युग सुहाउँदो, व्यावसायिक, प्राविधिक र आधुनिक हुनुपर्छ। यस्तो शिक्षाले मात्र देशलाई समृद्धिको मार्गमा डोऱ्याउन सक्छ।\r\n\r\n### ४. दिइएको अनुच्छेद पढी सोधिएका प्रश्नको उत्तर दिनुहोस्ः\r\n**(क) कानुन भन्नाले के बुझिन्छ ?**\r\n**उत्तर:** राज्यको शासन सञ्चालन गर्ने कार्य विधि, पद्धति एवम् नियमको समष्टिलाई कानुन भन्ने बुझिन्छ।\r\n\r\n**(ख) कानुनका स्रोत के के हुन् ?**\r\n**उत्तर:** विधायन, नजिर, प्रथा तथा परम्परा, संप्रतिज्ञा, अन्तर्राष्ट्रिय अदालतबाट भएका फैसला, अन्तर्राष्ट्रिय सन्धि, सम्झौता, कानुनविद्का राय र संहिताकरण कानुनका स्रोतहरु हुन्।\r\n\r\n**(ग) कानुनलाई किन बाध्यकारी शक्ति मानिन्छ ?**\r\n**उत्तर:** कानुनको अवज्ञा दण्डनीय हुने भएकाले यसलाई बाध्यकारी शक्ति मानिन्छ।\r\n\r\n**(घ) कानुनको महत्त्व लेख्नुहोस्।**\r\n**उत्तर:** शासन व्यवस्थालाई निरङ्कुश हुनबाट रोक्न, नागरिकलाई अधिकार दिन, असीमित अधिकारलाई नियन्त्रण गर्न, सामाजिक सदाचार र नैतिकता कायम गर्न, समतामूलक समाज निर्माण गर्न, न्याय प्रशासनलाई चुस्त र दुरुस्त बनाउन कानुनको महत्त्व रहेको हुन्छ।\r\n\r\n---\r\n\r\n## भाषिक संरचना र वर्णविन्यास (Linguistic Structure and Spelling)\r\n\r\n### १. दिइएका कर्तृवाच्यका वाक्यलाई कर्मवाच्यमा बदल्नुहोस्ः\r\n* **(क) विविषा कम्प्युटर किन्थिन्।**\r\n    * **उत्तर:** विविषाद्वारा कम्प्युटर किनिन्थ्यो।\r\n* **(ख) दर्शन लेखाशास्त्र पढ्‌दै छन्।**\r\n    * **उत्तर:** दर्शनद्वारा लेखाशास्त्र पढिँदै छ।\r\n* **(ग) समीक्षाले गीत गाइन्।**\r\n    * **उत्तर:** समीक्षाद्वारा गीत गाइयो।\r\n* **(घ) विद्यार्थीले शिक्षक भेटे।**\r\n    * **उत्तर:** विद्यार्थीद्वारा शिक्षक भेटिनुभयो।\r\n* **(ङ) भाइले फुटबल किन्यो।**\r\n    * **उत्तर:** भाइद्वारा फुटबल किनियो।\r\n* **(च) उसले थुप्रै किताब खोजेको छ।**\r\n    * **उत्तर:** ऊद्वारा थुप्रै किताब खोजिएका छन्।\r\n\r\n### २. दिइएका कर्मवाच्यका वाक्यलाई कर्तृवाच्यमा बदल्नुहोस्ः\r\n* **(क) मेनुकाद्वारा नेपाली पढाइन्छ।**\r\n    * **उत्तर:** मेनुकाले नेपाली पढाउँछिन्।\r\n* **(ख) आफू त लेख लेखिँदै छ।**\r\n    * **उत्तर:** म त लेख लेख्दै छु।\r\n* **(ग) भोलि त गीत गाइएला।**\r\n    * **उत्तर:** उसले भोलि गीत गाउला।\r\n* **(घ) मद्वारा अनुस्का पुस्तकालयमा भेटिइन्।**\r\n    * **उत्तर:** मैले अनुस्कालाई पुस्तकालयमा भेटें।\r\n* **(ङ) हामीद्वारा खेलकुदमा सहभागी भइयो।**\r\n    * **उत्तर:** हामी खेलकुदमा सहभागी भयौँ।\r\n* **(च) विश्वकप फुटबल खुब हेरियो।**\r\n    * **उत्तर:** मैले विश्वकप फुटबल खुब हेरें।\r\n\r\n### ३. दिइएका कर्तृवाच्यका वाक्यलाई भाववाच्यमा बदल्नुहोस्ः\r\n* **(क) म बिहान उठ्छु।**\r\n    * **उत्तर:** आफू बिहान उठिन्छ।\r\n* **(ख) उनीहरू घरबाट हिँडेछन्।**\r\n    * **उत्तर:** उनीहरूद्वारा घरबाट हिँडिएछ।\r\n* **(ग) हामी पोखरातिर घुम्न जान्छौँ।**\r\n    * **उत्तर:** हामीद्वारा पोखरा घुम्न गइन्छ।\r\n* **(घ) उनीहरू यहीं बसे।**\r\n    * **उत्तर:** उनीहरूद्वारा यहीँ बसियो।\r\n* **(ङ) साथीहरू मस्तसँग हाँस्थे।**\r\n    * **उत्तर:** साथीहरूद्वारा मस्तसँग हाँसिन्थ्यो।\r\n* **(च) म दिक्तेल बजार घुम्ने छु।**\r\n    * **उत्तर:** आफू त दिक्तेल बजार घुमिने छ।\r\n\r\n### ४. दिइएका भाववाच्यका वाक्यलाई कर्तृवाच्यमा बदल्नुहोस्ः\r\n* **(क) तिजमा मस्तसँग नाचिन्छ।**\r\n    * **उत्तर:** दिदी तिजमा मस्तसँग नाच्नुहुन्छ।\r\n* **(ख) कहाँबाट आइँदै छ ?**\r\n    * **उत्तर:** तिमी कहाँबाट आउँदै छौ ?\r\n* **(ग) मैदानमा कुदियो।**\r\n    * **उत्तर:** म मैदानमा कुदें।\r\n* **(घ) सानो हुँदा कुरै नबुझी रोइन्थ्यो।**\r\n    * **उत्तर:** म सानो हुँदा कुरै नबुझी रुन्थें।\r\n* **(ङ) पढ्दा पढ्दै निदाइएछ।**\r\n    * **उत्तर:** भाइ पढ्दापढ्दै निदाएछ।\r\n* **(च) पर्सि साफेबगर पुगिने छ।**\r\n    * **उत्तर:** हामी पर्सि साफेबगर पुग्ने छौँ।\r\n\r\n### ५. दिइएको अनुच्छेदका \'य\' र \'ए\' प्रयोगसम्बन्धी अशुद्धि सच्याएर लेख्नुहोस्ः\r\n**अशुद्ध:** यउटा विद्यार्थी पढ्न विद्यालए गयछ। उसलाई प्रशासनिक कार्यालए खोज्न समए लागेछ। एसरी खोज्ने क्रममा साथीले सहयोग गरेछन्। उसले साथीलाई धन्यवाद दियछ।\r\n**शुद्ध:** **एउटा** विद्यार्थी पढ्न **विद्यालय** **गएछ**। उसलाई प्रशासनिक **कार्यालय** खोज्न **समय** लागेछ। **यसरी** खोज्ने क्रममा साथीले सहयोग गरेछन्। उसले साथीलाई धन्यवाद **दिएछ**।\r\n\r\n---\r\n\r\n## सिर्जना र परियोजना कार्य (Creative and Project Work)\r\n\r\n### १. दिइएका शीर्षकमा १५० शब्दसम्मको निबन्ध लेख्नुहोस्ः\r\n\r\n#### **नेपालको आर्थिक विकासमा कृषिको भूमिका**\r\nनेपाल एक कृषि प्रधान देश हो, जहाँ आज पनि करिब ६० प्रतिशतभन्दा बढी जनसङ्ख्या कृषि पेसामा निर्भर छ। देशको कुल ग्राहस्थ्य उत्पादनमा कृषिको योगदान लगभग ३३ प्रतिशत रहेको छ, जसले यसलाई राष्ट्रिय अर्थतन्त्रको मेरुदण्डको रूपमा स्थापित गर्दछ। हाम्रो देशको भौगोलिक विविधताले कृषिमा अपार सम्भावना बोकेको छ; हिमालमा पशुपालन र जडीबुटी, पहाडमा फलफूल र तरकारी खेती, तथा तराईमा खाद्यान्न उत्पादन गर्न सकिन्छ।\r\n\r\nकृषि केवल गाँस, वास र कपासको स्रोत मात्र होइन, यो औद्योगिक विकासको मुख्य आधार पनि हो। कृषिमा आधारित उद्योगहरूलाई आवश्यक कच्चा पदार्थको आपूर्ति कृषि क्षेत्रबाटै हुन्छ। कृषि उत्पादन बढाउन सकेमा मात्र औद्योगिकरणले गति लिन सक्छ। यद्यपि, परम्परागत खेती प्रणाली, खण्डीकृत जमिन र सरकारी प्रयासहरूको सीमितताका कारण नेपालको कृषिले अपेक्षित प्रतिफल दिन सकेको छैन।\r\n\r\nअबको आवश्यकता भनेको कृषिलाई आधुनिकीकरण र व्यवसायीकरण गर्नु हो। सिँचाइ, मल, बिउ र प्रविधिको सहज पहुँच सुनिश्चित गर्दै युवाहरूलाई यस पेसामा आकर्षित गर्न सकेमा कृषिले देशको मुहार फेर्न सक्छ। व्यावसायिक कृषिले गरिबी र बेरोजगारी घटाउनुका साथै देशलाई खाद्य सुरक्षामा आत्मनिर्भर बनाउँदै आर्थिक विकासको दिशामा लम्काउन महत्त्वपूर्ण भूमिका खेल्न सक्छ।\r\n\r\n#### **अभिभावकप्रति मेरो जिम्मेवारी**\r\nमानिसको जीवनमा उसको परिवार नै सबैभन्दा पहिलो र महत्त्वपूर्ण पाठशाला हो। मलाई यो सुन्दर संसार देखाउनुहुने मेरा बुबाआमाप्रति मेरो विशेष जिम्मेवारी छ। एउटी आमाले सन्तानलाई जन्म दिन अनगिन्ती कष्ट सहन्छिन् र आफ्नो मायाले हुर्काउँछिन्। आमाबाबुको सहयोग, प्रेरणा र स्नेहबाट नै बालकको भविष्य निर्माण हुन्छ। यदि कोही डाक्टर, इन्जिनियर वा उच्च पदस्थ व्यक्ति बन्छ भने उसको पछाडि मातापिताको बलिदान र प्रेरणाको शक्ति लुकेको हुन्छ।\r\n\r\nमेरा लागि मेरा अभिभावक नै मेरा संसार हुन्। उहाँहरूले देखाउनुभएको बाटोमा हिँड्नु र उहाँहरूको सपना पूरा गर्नु मेरो मुख्य कर्तव्य हो। म सधैँ यो ख्याल राख्नेछु कि मबाट कुनै गलत कार्य नहोस्, जसले गर्दा उहाँहरूलाई लज्जित तुल्याओस्। आजको भौतिकवादी पुस्तामा अभिभावकलाई छोडेर विदेश पलायन हुने वा विवाहपछि स्वार्थी बन्ने चलन बढेको छ, तर मबाट यो भुल कहिल्यै हुने छैन। \'मातृदेवो भव, पितृदेवो भव\' अर्थात् मातापिता देवता हुन्। उहाँहरूलाई पूर्ण सम्मान दिनु र जीवनभर उहाँहरूको सहारा बनेर उहाँहरूलाई खुसी दिने प्रयास गर्नु मेरो परम जिम्मेवारी हो।\r\n\r\n#### **सिकाइमा प्रविधिको उपयोग**\r\nआजको युग विज्ञान र प्रविधिको युग हो। प्रविधिको प्रयोगले विद्यार्थीको सिकाइ, शिक्षकको क्षमता विकास र विद्यालयको व्यवस्थापन प्रक्रियालाई सहज र प्रभावकारी बनाएको छ। रेडियो, टेलिभिजन, इमेल, इन्टरनेट जस्ता साधनहरू सिकाइमा बढी प्रयोग हुने गर्दछन्। यस्ता प्रविधिलाई परम्परागत सामग्रीभन्दा बढी सान्दर्भिक, उपयुक्त एवं प्रभावकारी रूपमा प्रयोग गर्न सकिन्छ।\r\n\r\nप्रविधिको प्रयोगले विद्यार्थीहरूलाई कक्षाकोठाको चौघेराबाट बाहिर निकालेर विश्वव्यापी ज्ञानको भण्डारसँग जोड्दछ। विद्यार्थीहरूले आवश्यक पाठ्यसामग्री इन्टरनेटबाट कुनै पनि बेला डाउनलोड गर्न सक्छन्। यसले विद्यार्थीमा आत्मविश्वास र खोजी गर्ने बानीको विकास हुन्छ। कोरोनाको बन्दाबन्दीका समयमा यसको महत्त्व अझ बढेर गयो, जब प्रविधिले घरमै बसेर सिकाइलाई निरन्तरता दिन सम्भव बनायो।\r\n\r\nयद्यपि, प्रविधिको सहज पहुँच र दक्ष जनशक्तिको अभाव यसका चुनौतीहरू हुन्। तर, यस्ता चुनौतीहरूलाई सामना गर्दै प्रविधिको सदुपयोग गर्न सकेमा यसले शिक्षण सिकाइमा आमूल परिवर्तन ल्याउन सक्छ।', 1, '2025-07-25 01:11:38', '2025-09-16 03:05:11'),
(76, 11203, '# चिकित्सा विज्ञान र आयुर्वेद चिकित्सा - कक्षा १० (पूर्ण विस्तृत गाइड)\r\n\r\n\"चिकित्सा विज्ञान र आयुर्वेद चिकित्सा\" निबन्धले आधुनिक एलोप्याथिक चिकित्सा र हजारौँ वर्ष पुरानो आयुर्वेद चिकित्सा पद्धतिको परिचय, विशेषता, भिन्नता र महत्त्वलाई उजागर गर्दछ। यसले विद्यार्थीहरूलाई दुवै उपचार पद्धतिको सकारात्मक र नकारात्मक पक्षबारे जानकारी दिँदै नेपालमा उपलब्ध जडीबुटीको महत्त्वलाई पनि प्रस्ट्याउँछ। यो विस्तृत गाइडले परीक्षाको तयारीका लागि सबै प्रश्नहरूको गहन र पूर्ण उत्तरहरू समावेश गर्दछ।\r\n\r\n---\r\n\r\n## शब्दभण्डार (Vocabulary)\r\n\r\n### १. दिइएका अर्थ आउने शब्द पाठबाट खोजेर लेख्नुहोस् :\r\n* **स्नायुसम्बन्धी रोग:** पक्षाघात\r\n* **चिरफारका पद्धतिले गरिने रोगको उपचार:** शल्यक्रिया\r\n* **हानि वा घात पुऱ्याउने:** नकारात्मक प्रभाव\r\n* **प्रतिरोधका लागि तयार पारिएको:** प्रतिरोधात्मक\r\n\r\n### २. दिइएका शब्द र तिनका अर्थबिच जोडा मिलाउनुहोस् :\r\n\r\n| **शब्द** | **अर्थ** |\r\n| :--- | :--- |\r\n| प्रादुर्भाव | कुनै वस्तु वा विषयको उत्पत्ति वा उद्भव |\r\n| अत्युक्ति | बढाइचढाइ गरिने वर्णन वा कथन |\r\n| अद्यावधिक | आजसम्मको अवस्था, विगतदेखि हालसम्म |\r\n| त्रिदोष | शरीरमा हुने वात, पित्त र कफको प्रकोपबाट हुने रोग |\r\n| निषेध | प्रतिबन्ध वा रोक लगाउने काम |\r\n| अधीरता | धैर्य नभएको अवस्था, अस्थिर |\r\n\r\n### ३. चिकित्सा क्षेत्रमा प्रयोग हुने प्राविधिक पारिभाषिक शब्दको अर्थ लेख्नुहोस् :\r\n* **आयुर्वेद:** जडीबुटी तथा प्राकृतिक तत्वका माध्यमबाट गरिने संसारकै सबैभन्दा पुरानो उपचार पद्धति।\r\n* **एलोप्याथिक:** प्रयोगशालामा निर्मित रासायनिक औषधि र आधुनिक प्रविधिको प्रयोगबाट उपचार गरिने चिकित्सा पद्धति, जसलाई डाक्टरी उपचार पनि भनिन्छ।\r\n* **वैकल्पिक चिकित्सा:** मुख्य वा परम्परागत उपचार पद्धतिको सट्टा वा त्यसको सहायकको रूपमा प्रयोग गरिने अन्य उपचार पद्धतिहरू।\r\n* **होमियोप्याथिक चिकित्सा:** जुन पदार्थले स्वस्थ शरीरमा रोगको लक्षण उत्पन्न गराउँछ, त्यसै पदार्थको सूक्ष्म मात्रा प्रयोग गरी रोगको निदान गर्ने समान लक्षणमा आधारित उपचार पद्धति।\r\n* **शल्यक्रिया:** शरीरका अङ्गहरूलाई चिरफार गरी गरिने रोगको उपचार।\r\n* **पक्षाघात:** शरीरको कुनै भाग वा अङ्ग नचल्ने वा चेतनाशून्य हुने स्नायुसम्बन्धी रोग।\r\n* **आकस्मिक उपचार:** दुर्घटना, हृदयाघात जस्ता एक्कासि आइलाग्ने गम्भीर स्वास्थ्य अवस्थामा तुरुन्तै गरिने उपचार।\r\n* **निर्मूलीकरण:** कुनै पनि रोगलाई जडैदेखि हटाउने वा पूर्ण रूपमा निदान गर्ने काम।\r\n\r\n### ४. निबन्धमा प्रयोग भएका पारिभाषिक र प्राविधिक शब्द टिपी वाक्यमा प्रयोग गर्नुहोस् :\r\n* **एलोप्याथिक:** **एलोप्याथिक** लाई डाक्टरी उपचार पद्धति भनिन्छ।\r\n* **चिकित्सा:** **चिकित्सा** बाट धेरै मानिसको रोगको उपचार भएको छ।\r\n* **होमियोप्याथी:** **होमियोप्याथी** समान लक्षण उब्जाउने औषधीय पदार्थद्वारा नै कुनै रोगको निदान गर्ने पद्धति हो।\r\n* **एपेन्डिसाइटिस:** **एपेन्डिसाइटिस** शल्यक्रियाबाट उपचार गर्न सकिन्छ।\r\n* **हृदयाघात:** **हृदयाघात** का कारण बर्सेनि हजारौं मान्छेको ज्यान जाने गर्छ।\r\n\r\n---\r\n\r\n## बोध र अभिव्यक्ति (Comprehension and Expression)\r\n\r\n### १. दिइएका प्रश्नको उत्तर भन्नुहोस् :\r\n* **(क) \'चिकित्सा विज्ञान र आयुर्वेद चिकित्सा\' निबन्ध कति अनुच्छेदमा संरचित छ ?**\r\n    **उत्तर:** \'चिकित्सा विज्ञान र आयुर्वेद चिकित्सा\' निबन्ध १२ अनुच्छेदमा संरचित छ।\r\n* **(ख) वाक्य सङ्ख्याका दृष्टिले सबैभन्दा छोटो र लामो अनुच्छेद कुन हो ?**\r\n    **उत्तर:** वाक्य सङ्ख्याका दृष्टिले सबैभन्दा छोटो अन्तिम र लामो अनुच्छेद तेस्रो हो।\r\n* **(ग) निबन्धमा आयुर्वेद चिकित्साका शाखाको चर्चा गरिएको विषयवस्तु कुन अनुच्छेदमा रहेको छ ?**\r\n    **उत्तर:** निबन्धमा आयुर्वेद चिकित्साका शाखाको चर्चा गरिएको विषयवस्तु पाँचौं अनुच्छेदमा रहेको छ।\r\n* **(घ) निबन्धको अन्तिम अनुच्छेदको आशय के हो ?**\r\n    **उत्तर:** निबन्धको अन्तिम अनुच्छेदको आशय निरोगी र सुखी जीवन बाँच्नु छ भने आयुर्वेद चिकित्सा पद्धतिको प्रयोग गर्नुपर्छ भन्ने हो।\r\n\r\n### २. दिइएको निबन्धांश मौन पठन गरी सोधिएका प्रश्नको उत्तर दिनुहोस् :\r\n* **(क) निबन्धांशमा चिकित्सा विज्ञानका कुन कुन शाखाको चर्चा गरिएको छ ?**\r\n    **उत्तर:** निबन्धांशमा चिकित्साका निरोधात्मक, प्रवर्धनात्मक र उपचारात्मक शाखाको चर्चा गरिएको छ।\r\n* **(ख) प्रवर्धनात्मक उपचार पद्धति कस्तो हुन्छ ?**\r\n    **उत्तर:** पोषण कार्यक्रम, स्वास्थ्य शिक्षा, वातावरणीय सरसफाइ कार्यक्रम जस्ता सेवाबाट उपचार गरिने पद्धति प्रवर्धनात्मक उपचार पद्धति हो।\r\n* **(ग) उपचारात्मक स्वास्थ्य सेवामा कुन कुन पद्धति पर्छन् ?**\r\n    **उत्तर:** उपचारात्मक स्वास्थ्य सेवामा आधुनिक चिकित्सा, आयुर्वेद चिकित्सा, होमियोप्याथी, प्राकृतिक चिकित्सा, योग चिकित्सा, मनोचिकित्सा, अकुप्रेसर, युनानी चिकित्सा पद्धति पर्छन्।\r\n* **(घ) तपाईँलाई कुन उपचार पद्धति मन पर्छ, किन ?**\r\n    **उत्तर:** रोग नियन्त्रणका लागि रोग लाग्नुपूर्व नै स्वास्थ्य सेवा प्रदान गरिने भएकोले मलाई निरोधात्मक उपचार पद्धति मन पर्छ।\r\n\r\n### ३. दिइएका प्रश्नको उत्तर लेख्नुहोस् :\r\n**(क) वर्तमान चिकित्सा विज्ञानका बारेमा वर्णन गर्नुहोस्।**\r\n**उत्तर:** वर्तमान चिकित्सा विज्ञान, जसलाई एलोप्याथिक उपचार पद्धति वा डाक्टरी उपचार पनि भनिन्छ, हाल विश्वमा सर्वाधिक प्रयोगमा रहेको र लोकप्रिय चिकित्सा पद्धति मानिन्छ। यस पद्धतिमा रोग निको पार्नका लागि सुरुमै रोग घटाउने औषधि दिइन्छ। छिटो निको हुनु, विशेषज्ञ डाक्टर र औषधि सजिलै उपलब्ध हुनु यसका प्रमुख विशेषता हुन्। यो पद्धति आपतकालीन अवस्थामा निकै प्रभावकारी साबित भएको छ। शल्यक्रियामार्फत गम्भीर रोगहरू निको पार्नु पनि यसको महत्त्वपूर्ण विशेषता हो। साथै, यसमा प्रयोग हुने प्रविधि र उपकरणहरू समय-समयमा अद्यावधिक गरिनु, सानादेखि ठुला सबै रोगको उपचारमा प्रभावकारी हुनु र ठुलो रोग लाग्नुअघि नै खोपमार्फत रोकथाम गर्नु यसका थप विशेषताहरू हुन्।\r\n\r\n**(ख) किन आयुर्वेद चिकित्साको लोकप्रियता बढ्दै गएको छ, लेख्नुहोस्।**\r\n**उत्तर:** आयुर्वेद चिकित्साका धेरै सकारात्मक पक्ष भएकाले यसको लोकप्रियता दिनानुदिन बढ्दै गएको छ। यसले शरीरको शुद्धीकरण गर्ने र रोग प्रतिरोधात्मक क्षमता बढाउने काम गर्छ। यस पद्धतिमा बिरामीको आत्मा, मन र शारीरिक प्रकृतिलाई समेत ध्यानमा राखेर समग्र पक्षको उपचार गरिन्छ। यसका प्रमुख विशेषताहरूमा जडीबुटीको प्रयोग हुनु, चिरफार कम हुनु, रोगको लक्षणका आधारमा उपचार गरिनु, र उपचारका लागि आवश्यक जडीबुटी नेपालमै पाइनु पर्दछन्। साथै, यसले रोगको नियन्त्रण मात्र नगरी निर्मूल गर्ने लक्ष्य राख्छ। उपचारमा महँगा उपकरणको आवश्यकता नपर्नु, औषधिको नकारात्मक प्रभाव (साइड इफेक्ट) कम हुनु र कम खर्चिलो हुनुले पनि यसलाई लोकप्रिय बनाएको छ। यी कारणहरूले गर्दा आयुर्वेद चिकित्साप्रति मानिसको आकर्षण बढेको हो।\r\n\r\n**(ग) उपचारात्मक स्वास्थ्य सेवाअन्तर्गत कस्ता उपचारात्मक पद्धति पर्छन् ?**\r\n**उत्तर:** रोग लागेपछि त्यसलाई निको पार्नका लागि प्रदान गरिने स्वास्थ्य सेवालाई उपचारात्मक स्वास्थ्य सेवा भनिन्छ। यस सेवाअन्तर्गत आधुनिक चिकित्सा विज्ञान, आयुर्वेद चिकित्सा पद्धति, होमियोप्याथी, प्राकृतिक चिकित्सा, योग चिकित्सा, मनोचिकित्सा, अकुप्रेसर, र युनानी चिकित्सा जस्ता अनेकौँ उपचार पद्धतिहरू पर्दछन्।\r\n\r\n**(घ) आयुर्वेद चिकित्सा पद्धति र आधुनिक चिकित्सा पद्धतिका मुख्य फरक के के हुन् ?**\r\n\r\n| **आयुर्वेद चिकित्सा पद्धति** | **आधुनिक चिकित्सा पद्धति (एलोप्याथिक)** |\r\n| :--- | :--- |\r\n| शरीरको शुद्धीकरण र रोग प्रतिरोधात्मक क्षमता बढाउनमा केन्द्रित छ। | रोग निको पार्नका लागि सुरुमै रोग घटाउने औषधि दिइन्छ। |\r\n| उपचारमा जडीबुटीको प्रयोग हुन्छ र यसलाई प्राकृतिक उपचार पद्धति भनिन्छ। | उपचारमा आधुनिक औषधि, खोप, स्लाइन आदिको प्रयोग हुन्छ र यसलाई डाक्टरी उपचार भनिन्छ। |\r\n| उपचारमा उपकरणको आवश्यकता कम पर्छ, औषधिको नकारात्मक प्रभाव कम हुन्छ र यो कम खर्चिलो छ। | छिटो निको हुन्छ, आधुनिक उपकरण आवश्यक पर्छ, यो खर्चिलो छ र विशेषज्ञ डाक्टर सजिलै उपलब्ध हुन्छन्। |\r\n| स्वस्थ व्यक्तिले पनि पोषण र रोग प्रतिरोधात्मक क्षमता बढाउन प्रयोग गर्न सक्छन्। | गम्भीर प्रकृति र आकस्मिक उपचार गर्नुपर्ने बिरामीहरूका लागि यो महत्त्वपूर्ण छ। |\r\n| उपचार अवधि लामो भए पनि रोग फेरि बल्झिने सम्भावना कम हुन्छ। | उपचार अवधि छोटो भए पनि रोग फेरि बल्झिने सम्भावना रहन सक्छ। |\r\n\r\n### ४. व्याख्या गर्नुहोस् :\r\n\r\n**(क) आयुर्वेदिक चिकित्सा आधुनिक चिकित्सा पद्धतिभन्दा भिन्न र संसारकै सर्वप्राचीन उपचार पद्धति हो।**\r\n**प्रस्तुत सन्दर्भ:** यो वाक्यांश \"चिकित्सा विज्ञान र आयुर्वेद चिकित्सा\" निबन्धबाट साभार गरिएको हो। यसले आयुर्वेद चिकित्साको ऐतिहासिकता र मौलिकतालाई आधुनिक चिकित्सा पद्धतिसँग तुलना गर्दै यसको प्राचीन महत्त्वलाई उजागर गरेको छ।\r\n\r\n**विस्तृत व्याख्या:** आयुर्वेद चिकित्सा र आधुनिक चिकित्सा पद्धति मौलिक रूपमै भिन्न छन्। आयुर्वेदले शरीरको शुद्धीकरण र रोग प्रतिरोधात्मक क्षमता बढाएर रोगलाई निर्मूल गर्ने लक्ष्य राख्छ भने आधुनिक चिकित्साले तत्काल लक्षणहरूलाई दबाएर छिटो निको पार्नेमा जोड दिन्छ।\r\n\r\nआयुर्वेद संसारकै सर्वप्राचीन चिकित्साशास्त्र हो भन्ने कुराका पछाडि बलिया ऐतिहासिक प्रमाणहरू छन्। यसको चर्चा हिन्दू धर्मको चौथो वेद, अथर्ववेदमा पाइन्छ। यो इशापूर्व ३ हजारदेखि ५० हजार वर्ष पहिले भारतवर्षबाट विकास भएको मानिन्छ। यसको ज्ञानका मुख्य स्रोत ब्रह्मालाई मानिन्छ, जसले यो ज्ञान दक्ष प्रजापति, अश्विनीकुमारहरू, इन्द्र हुँदै आयुर्वेदका सुरुवातकर्ता मानिने धनवन्तरीसम्म पुऱ्याएको विश्वास गरिन्छ। रामायण र महाभारत जस्ता प्राचीन ग्रन्थहरूमा पनि ऋषिहरूले आयुर्वेदको प्रयोगबाट उपचार गरेका प्रसङ्गहरू भेटिन्छन्। यसको विपरीत, आधुनिक चिकित्सा पद्धतिको सुरुवात अठारौँ शताब्दी पछि मात्र भएको मानिन्छ। यी ऐतिहासिक तथ्यहरूले आयुर्वेद चिकित्सा आधुनिक पद्धतिभन्दा भिन्न र संसारकै सबैभन्दा पुरानो उपचार पद्धति हो भन्ने कुरालाई स्पष्ट रूपमा पुष्टि गर्दछ।\r\n\r\n**(ख) आयुर्वेदिक औषधीका लागि नेपाल भूस्वर्ग मानिन्छ।**\r\n**प्रस्तुत सन्दर्भ:** यो वाक्यांश \"चिकित्सा विज्ञान र आयुर्वेद चिकित्सा\" निबन्धबाट लिइएको हो। यसले नेपालको प्राकृतिक सम्पदा र जैविक विविधताले आयुर्वेद चिकित्साका लागि प्रदान गरेको अपार सम्भावनालाई सङ्केत गर्दछ।\r\n\r\n**विस्तृत व्याख्या:** आयुर्वेदिक उपचार पद्धतिको मुख्य आधार नै जडीबुटी हो, र नेपाल जडीबुटीको विशाल भण्डार हो। नेपालको हिमाल, पहाड र तराईमा पाइने जैविक विविधताका कारण यहाँ विविध औषधीय गुण भएका जडीबुटीहरू उपलब्ध छन्। परापूर्वकालदेखि नै हाम्रा पुर्खाहरूले यिनै जडीबुटीबाट उपचार गरी दीर्घजीवन हासिल गरेका थिए। आज विकसित देशहरूले समेत यिनै जडीबुटीलाई आधुनिक औषधि उद्योगका लागि बहुमूल्य कच्चा पदार्थको रूपमा प्रयोग गरेका छन्।\r\n\r\nरामायणमा युद्धमा घाइते भएका लक्ष्मणको उपचारका लागि सञ्जीवनी बुटी लिन नेपालको हिमालय क्षेत्रमा हनुमानलाई पठाइएको प्रसङ्गले परापूर्वकालदेखि नै नेपाल आयुर्वेदिक जडीबुटीको केन्द्र रहेको पुष्टि गर्छ। नेपालमा तुलसी, सर्पगन्धा, जटामसी, पाँचऔँले, यार्सागुम्बा जस्ता बहुमूल्य र दुर्लभ जडीबुटीहरू पाइन्छन्। विशेषगरी डोल्पा, जुम्ला, मुगु, हुम्ला जस्ता उच्च पहाडी जिल्लाहरू जडीबुटीका लागि प्रख्यात छन्। यदि यी जडीबुटीहरूको सही सम्भाव्यता अध्ययन, संरक्षण र सदुपयोग गर्ने हो भने यसले नेपालको समृद्धिको ढोका खोल्न सक्छ। यही अपार प्राकृतिक सम्पदाका कारण नेपाललाई आयुर्वेदिक औषधिका लागि \'भूस्वर्ग\' मानिएको हो।\r\n\r\n### ५. आधुनिक चिकित्सा पद्धतिका सकारात्मक र नकारात्मक पक्षबारे समीक्षा गर्नुहोस्।\r\n**उत्तर:** \'चिकित्सा विज्ञान र आयुर्वेद चिकित्सा\' निबन्धले आधुनिक चिकित्सा पद्धतिका सबल र कमजोर दुवै पक्षलाई उजागर गरेको छ।\r\n\r\n**सकारात्मक पक्ष:**\r\nआधुनिक चिकित्सा पद्धति, जसलाई एलोप्याथी पनि भनिन्छ, आज विश्वमा सर्वाधिक लोकप्रिय छ। यसका मुख्य सबल पक्षहरूमा रोगको छिटो निदान र उपचार हुनु, विशेषज्ञ डाक्टर र औषधिहरू सजिलै उपलब्ध हुनु, र आपतकालीन अवस्थाहरूमा यो अत्यन्तै प्रभावकारी हुनु पर्दछन्। शल्यक्रियामार्फत गम्भीर रोगहरू निको पार्नु र खोपको माध्यमबाट रोगहरू लाग्नुअघि नै रोकथाम गर्नु यसका महत्त्वपूर्ण उपलब्धिहरू हुन्। यसले गर्दा मानिसहरूको औसत आयु बढेको छ र स्वास्थ्य सेवा पहिलेभन्दा सुलभ भएको छ।\r\n\r\n**नकारात्मक पक्ष:**\r\nयति धेरै सकारात्मक पक्ष हुँदाहुँदै पनि यसका केही नकारात्मक पक्षहरू पनि छन्। आधुनिक औषधि र स्वास्थ्य सेवा प्रायः अत्यधिक महँगो हुन्छ, जसले गर्दा यो विपन्न मानिसहरूको पहुँचभन्दा बाहिर छ। औषधिहरूले कहिलेकाहीँ गम्भीर साइड इफेक्टहरू निम्त्याउन सक्छन्। एन्टिबायोटिक जस्ता औषधिहरूको अत्यधिक प्रयोगले शरीरको प्रतिरोधी क्षमतालाई कमजोर बनाउँदै लगेको छ। कहिलेकाहीँ यो पद्धतिले रोगको मूल कारणलाई सम्बोधन गर्नुको सट्टा केवल लक्षणहरूको उपचारमा मात्र केन्द्रित भएको आरोप पनि लाग्ने गर्छ।\r\n\r\n**निष्कर्ष:**\r\nयति हुँदाहुँदै पनि, गम्भीर प्रकृति र आकस्मिक उपचार गर्नुपर्ने बिरामीहरूका लागि आधुनिक चिकित्सा पद्धतिको विकल्प छैन।\r\n\r\n---\r\n\r\n## भाषिक संरचना र वर्णविन्यास (Linguistic Structure and Spelling)\r\n\r\n### १. दिइएका उपसर्ग लगाई एक-एकओटा शब्द निर्माण गर्नुहोस् :\r\n* **अ:** अ + न्याय = अन्याय\r\n* **बि:** बि + सन्चो = बिसन्चो\r\n* **ना:** ना + लायक = नालायक\r\n* **परि:** परि + कल्पना = परिकल्पना\r\n* **सम्:** सम् + भावना = सम्भावना\r\n* **कु:** कु + कर्म = कुकर्म\r\n* **सु:** सु + रक्षा = सुरक्षा\r\n\r\n### २. दिइएका प्रत्यय लगाई एक-एकओटा शब्द निर्माण गर्नुहोस् :\r\n* **अक्कड:** भुल् + अक्कड = भुलक्कड\r\n* **आइ:** पढ् + आइ = पढाइ\r\n* **आली:** लेक + आली = लेकाली\r\n* **इलो:** रस + इलो = रसिलो\r\n* **ले:** गाउँ + ले = गाउँले\r\n* **इक:** समाज + इक = सामाजिक\r\n* **ता:** मानव + ता = मानवता\r\n* **मान्:** शक्ति + मान् = शक्तिमान्\r\n\r\n### ३. दिइएको अनुच्छेद पढी शब्दको सुरु, बिच र अन्तिममा ह्रस्व उकार प्रयोग भएका शब्दको पहिचान गरी टिपोट गर्नुहोस् :\r\n**उत्तर:**\r\n* **सुरुमा ह्रस्व उकार:** बुबा, मुकुन्दपुर, सुब्बा, गुरु, बुलेन्दु, गुन्जमान, गुरुङ, सुख, खुसी।\r\n* **बिचमा ह्रस्व उकार:** आउनुभएको, बाबुराम, आयुर्वेदिक, जमुना, ताप्लेजुङ, घान्द्रुक, गुरुङ।\r\n* **अन्तिममा ह्रस्व उकार:** दाजु, राजु, गहुँ, पृथु, श्यामु, मधु, बुलेन्दु।\r\n\r\n---\r\n\r\n## सिर्जना र परियोजना कार्य (Creative and Project Work)\r\n\r\n### १. \'नेपालको प्राकृतिक विविधता\' शीर्षकमा वस्तुपरक निबन्ध लेख्नुहोस्।\r\n**नेपालको प्राकृतिक विविधता**\r\nविश्वको मानचित्रमा भौगोलिक हिसाबले सानो देखिए पनि नेपाल प्रकृति, कला, संस्कृति र भूगोलको विविधताले भरिपूर्ण एक अनुपम देश हो। बारै महिना हिउँले ढाकिने उच्च हिमशृङ्खला, हरियालीले भरिएका पहाड र अन्नको भण्डार मानिने तराई-मधेसले नेपालको भू-धरातललाई विशिष्ट बनाएको छ। समुद्र सतहबाट करिब ६० मिटरको होचो भू-भागदेखि विश्वको सर्वोच्च शिखर सगरमाथा (८,८४८.८६ मिटर) सम्मको उचाइले यहाँको प्राकृतिक विविधतालाई अझ बढाएको छ।\r\n\r\nहिमालसँग अथाह सौन्दर्य र जलस्रोत छ, पहाडसँग जडीबुटी, खनिज र स्वस्थ पर्यावरण छ भने तराई मधेसमा अन्नको भण्डार छ। यही विविधताका कारण नेपाल जैविक विविधतामा पनि धनी छ। नेपाल जलसम्पदामा विश्वकै अग्रणी देशहरूमा पर्छ। यहाँ कोसी, गण्डकी, कर्णाली जस्ता ठुला नदीहरू र रारा, फेवा, तिलिचो जस्ता सुन्दर तालतलैयाहरू छन्। यी जलसम्पदाले विद्युत् उत्पादन, सिँचाइ र पर्यटन व्यवसाय (र्याफ्टिङ, जलविहार) मा ठुलो सहयोग पुऱ्याएको छ।\r\n\r\nयहाँका वनजङ्गलमा यार्सागुम्बा, पाँचऔँले, जटामसी जस्ता बहुमूल्य जडीबुटीहरू पाइन्छन्, जसलाई विदेशमा निर्यात गरी मनग्य आम्दानी गर्न सकिन्छ। नेपाल प्राकृतिक विविधताले भरिपूर्ण देश हो, जसले सम्भावनाका अनन्त ढोकाहरू खोलेको छ। हामीले यी प्राकृतिक सम्पदाको सही पहिचान र सदुपयोग गरेर देशलाई विकसित र समृद्ध बनाउनुपर्छ।', 1, '2025-07-25 01:11:38', '2025-09-16 03:05:11'),
(77, 11212, '# पाब्लो पिकासो - कक्षा १० (पूर्ण विस्तृत गाइड)\r\n\r\n\"पाब्लो पिकासो\" जीवनीले विद्यार्थीहरूलाई बीसौं शताब्दीका सबैभन्दा महान् र प्रभावशाली कलाकारहरू मध्ये एकको जीवन, कला र विरासतसँग परिचित गराउँछ। यो विस्तृत गाइडले जीवनीका हरेक पक्ष, मुख्य विषयवस्तु, विश्लेषण र अभ्यासका सबै प्रश्नहरूको गहन र पूर्ण उत्तरहरू समावेश गर्दछ, जसले विद्यार्थीहरूलाई पिकासोको कलाको महत्त्व बुझ्न र परीक्षामा उत्कृष्टता हासिल गर्न मद्दत गर्नेछ।\r\n\r\n---\r\n\r\n## शब्दभण्डार (Vocabulary)\r\n\r\n### १. दिइएका अर्थसँग मिल्ने शब्द जीवनीबाट खोजेर लेख्नुहोस् :\r\n* **सय वर्षको समय वा पिरियड:** शताब्दी\r\n* **मूर्त नभएको:** अमूर्त\r\n* **अत्यन्त धेरै मोल पर्ने:** अनमोल\r\n* **कहिल्यै नमर्ने:** अमर\r\n* **कलापूर्ण ढङ्गले सजाइएको:** कलात्मक\r\n* **प्राचीन महत्त्वका वस्तु राखिने ठाउँ:** सङ्ग्रहालय\r\n\r\n### २. जीवनीका आधारमा शब्दको अर्थ लेख्नुहोस् :\r\n* **अद्भुत:** आश्चर्य, अनौठो कुरा\r\n* **शैशवावस्था:** शिशु अवस्था\r\n* **पूर्णकालीन:** पूरा समयका लागि हुने\r\n* **बहुमुखी:** विभिन्न विषयको विशेषता वा ज्ञान भएको\r\n* **सिर्जना:** रचना\r\n* **आकृति:** कुनै व्यक्ति वा वस्तुको स्वरुप\r\n* **मनस्थिति:** मनको स्थिति, विचार\r\n* **विसङ्गत:** नमिलेको, नसुहाउँदो\r\n* **कृति:** कुनै पुस्तक, चित्र आदिको रचना\r\n\r\n### ३. दिइएको अनुच्छेदबाट आगन्तुक शब्द पहिचान गरी लेख्नुहोस् :\r\n**उत्तर:** आगन्तुक शब्दहरू: किताब, कापी, कलम, फोन, माइक्रोबस, डम्फु, समयबजी, योमरी, बारा, थर्मस, रक गार्डेन, क्यामेरा, कैद, नास्ता।\r\n\r\n### ४. जीवनीबाट पाँचओटा आगन्तुक शब्द टिपी भिन्न तरिकाले वाक्यमा प्रयोग गर्नुहोस् :\r\n* **जादु (फारसी):** मलाई **जादु** हेर्न मन पर्छ।\r\n* **नसा (अरबी):** रक्सीको **नसा** लागेपछि छुट्न कठिन हुन्छ।\r\n* **पिरियड (अङ्ग्रेजी):** हाम्रो विद्यालयमा पहिलो **पिरियड**मा नेपाली विषयको पढाइ हुन्छ।\r\n* **तनाव (हिन्दी):** परीक्षा नजिकिँदै जाँदा विद्यार्थीहरूले अनावश्यक **तनाव** लिनुहुँदैन।\r\n* **क्यानभास (अङ्ग्रेजी):** चित्रकारले **क्यानभास**मा सुन्दर प्रकृतिको चित्र कोरेका छन्।\r\n\r\n---\r\n\r\n## बोध र अभिव्यक्ति (Comprehension and Expression)\r\n\r\n### १. दिइएका घटना कुन-कुन मितिमा भएका हुन्, लेख्नुहोस् :\r\n* **स्पेनको सामान्य मध्यमवर्गीय परिवारमा पिकासोको जन्म हुनु:** सन् १८८१ अक्टोबर २५\r\n* **पिकासोको परिवार ला कोरुनामा बसाइँ सर्नु:** सन् १८९२\r\n* **पिकासोले आफ्ना चित्र प्रदर्शन गर्न र बेच्न थाल्नु:** सन् १८९५\r\n* **अन्तर्राष्ट्रिय लेनिन पुरस्कारबाट पिकासो सम्मानित हुनु:** सन् १९५० र सन् १९६१\r\n* **पिकासोको \'वुमन अफ अल्जियर्स\' ले विश्व कीर्तिमान राख्नु:** सन् १९५५\r\n* **पिकासोको भौतिक शरीरको अवसान हुनु:** सन् १९७३ अप्रिल ८\r\n\r\n### २. दिइएका प्रश्नको उत्तर लेख्नुहोस् :\r\n\r\n**(क) पिकासोको बाल्यकाल कस्तो परिवेशमा बित्यो?**\r\n**उत्तर:** पाब्लो पिकासोको जन्म सन् १८८१ अक्टोबर २५ मा स्पेनको मलागामा एक सामान्य मध्यमवर्गीय परिवारमा भएको थियो। उनका बुबा, जोसो रुइज, एक स्थानीय विद्यालयमा कलाका कुशल शिक्षक थिए। यसकारण, पिकासोले कलात्मक र प्रेरणादायी पारिवारिक परिवेश पाए। उनले बाल्यकालमै आफ्ना बुबाले सिर्जना गरेका सुन्दर कलाहरू बालसुलभ आँखाले देखे र त्यसैबाट उनीभित्रको जन्मजात कलाकारिताले मौलाउने अवसर पायो। उनले चित्रकलाको प्रारम्भिक तालिम घरबाटै पाए र बाल्यकालमा विभिन्न प्रकारका आकृतिहरू बनाएर आफ्ना साथीहरूलाई चकित पार्थे। यसरी उनको बाल्यकाल कला र सिर्जनाका लागि सहज र अनुकूल परिवेशमा बितेको थियो।\r\n\r\n**(ख) पिकासोले चित्रमा कुन-कुन पक्ष समेटेका छन्?**\r\n**उत्तर:** पिकासोले आफ्ना चित्रहरूमा मानव जीवनका अत्यन्तै विविध र गहिरा पक्षहरूलाई समेटेका छन्। प्रारम्भमा उनले यथार्थवादी शैलीमा आफ्नो परिवारका चित्रहरू र पोट्रेटहरू बनाए। पछि उनको कला \'ब्लु पिरियड\'मा प्रवेश गर्‍यो, जहाँ उनले निलो र हरियो रङको प्रयोग गरी समाजका गरिब, बहिष्कृत, दृष्टिविहीन र दुःखी मानिसहरूको एक्लोपन र पीडालाई मार्मिक रूपमा प्रस्तुत गरे। उनका चित्रहरूमा गरिबीले आक्रान्त महिला र दुधे बालकसँगका आमाका चित्रले प्राथमिकता पाए। उनले महिलाका प्रेमिल चित्रहरू पनि बनाए। कलामा \'घनवाद\'को सुरुवात गरेर उनले वस्तुलाई विभिन्न कोणबाट एकैसाथ देखाउने क्रान्तिकारी शैली अपनाए। उनको विश्वप्रसिद्ध चित्र \'द गुएर्निका\'ले युद्धको अमानवीयता र त्रासदीलाई सशक्त रूपमा प्रस्तुत गरेको छ, जुन हालसम्मकै सबैभन्दा महान् युद्धविरोधी चित्र मानिन्छ। यसरी उनले व्यक्तिगत भावनादेखि सामाजिक यथार्थ र राजनीतिक विद्रोहसम्मका विषयलाई आफ्ना चित्रमा समेटेका छन्।\r\n\r\n**(ग) पिकासोले आफ्नो जीवनको लक्ष्य पूरा गर्न कस्ता सङ्घर्ष गर्नुपरेको थियो?**\r\n**उत्तर:** पिकासोले आफ्नो जीवनको लक्ष्य पूरा गर्न अनेकौँ सङ्घर्षहरूको सामना गर्नुपरेको थियो। मध्यमवर्गीय परिवारमा जन्मेकाले जीवनको पूर्वार्धमा उनले आर्थिक तथा पारिवारिक समस्या भोगे। सन् १८९५ मा उनकी सात वर्षकी बहिनी कोन्चियको मृत्यु भयो, जुन उनको जीवनको एक कहालीलाग्दो घटना बन्यो। यी पारिवारिक र आर्थिक सङ्कटहरूले उनमा गहिरो मानसिक तनाव सिर्जना गर्‍यो। उच्च शिक्षाका लागि म्याड्रिड एकेडेमी गए पनि त्यहाँको वातावरणबाट विरक्तिएर उनले औपचारिक पढाइ छोडे र पूर्णकालीन कलाकारितामा समर्पित भए। प्रारम्भिक चरणमा उनका चित्रहरू मन पराउने मानिस कम थिए र बिक्री पनि हुँदैनथे। कतिपय अवस्थामा उनका चित्रहरूमाथि प्रतिबन्ध समेत लगाइएको थियो। उनको वैवाहिक र पारिवारिक जीवन पनि सधैँ सहज रहेन। यसरी उनले आर्थिक, पारिवारिक र मानसिक समस्याहरूसँग जुध्दै आफ्नो लक्ष्य पूरा गर्न कठोर सङ्घर्ष गर्नुपरेको थियो।\r\n\r\n**(घ) पिकासोको जीवनबाट पाइने जीवनोपयोगी सन्देश उल्लेख गर्नुहोस्।**\r\n**उत्तर:** पाब्लो पिकासोको जीवनीबाट निम्न जीवनोपयोगी सन्देशहरू पाउन सकिन्छ:\r\n* हरेक बालबालिकामा विशिष्ट सिर्जना शक्ति र प्रतिभा हुन्छ; उचित अवसर र लगनशीलता पाएमा उनीहरूले जीवनलाई सार्थक बनाउन सक्छन्।\r\n* अभिभावकले आफ्ना सन्तानको क्षमता पहिचान गरी त्यसलाई प्रस्फुटन हुनका लागि उपयुक्त वातावरण तयार पार्नुपर्छ।\r\n* आफ्नो रुचिको क्षेत्रमा निरन्तर साधना र लगनशीलताले नै सफलता हासिल गर्न सकिन्छ।\r\n* सादा जीवन र उच्च विचार राख्नुपर्छ; भौतिक सम्पन्नता भएर पनि साधारण जीवन जिउन सकिन्छ।\r\n* जीवनमा आउने सानातिना बाधा र अवरोधहरूसँग हार मान्नुहुँदैन।\r\n* हतियारको शक्तिभन्दा कलम र कुचीको शक्ति धेरै शक्तिशाली र दिगो हुन्छ।\r\n\r\n### ३. व्याख्या गर्नुहोस् :\r\n\r\n**(क) हरेक बालबालिकामा विशिष्ट सिर्जना शक्ति र प्रतिभा हुन्छ, उचित अवसर र लगनशीलता भए ऊ एउटा कलाकार बन्न सक्छ, जीवनलाई सार्थक बनाउन सक्छ र संसारलाई चहकिलो ज्योति छर्न सक्छ।**\r\n**प्रस्तुत सन्दर्भ:** यो गहन र प्रेरणादायी वाक्यांश पाब्लो पिकासोको जीवनीबाट लिइएको हो। यसले सफलताका लागि आवश्यक तीन तत्वहरू—जन्मजात प्रतिभा, उपयुक्त अवसर र निरन्तर लगनशीलता—बिचको सम्बन्धलाई उजागर गर्दछ। पिकासोले आफ्नी आमाको प्रेरक भनाइलाई स्मरण गर्दै आफू कसरी सफल कलाकार बने भन्ने सन्दर्भमा यो विचार आएको हो।\r\n\r\n**विस्तृत व्याख्या:** यस भनाइको मूल आशय हो कि हरेक बालबालिका सम्भावनाको खानी हो। उनीहरूभित्र कुनै न कुनै रूपमा विशिष्ट सिर्जनात्मक शक्ति र प्रतिभा लुकेको हुन्छ। तर, त्यो प्रतिभा आफैँ प्रस्फुटित हुँदैन। त्यसका लागि दुई कुरा अनिवार्य हुन्छन्: **उचित अवसर** र **लगनशीलता**।\r\n\r\nपिकासोको जीवन यसको उत्कृष्ट उदाहरण हो। उनका बुबा एक कलाकार भएकोले उनले घरमै कलात्मक वातावरण पाए, जुन उनका लागि **उचित अवसर** थियो। उनकी आमाले उनलाई सधैँ प्रेरित गरिरहिन्। उनले यो अवसरको पूर्ण सदुपयोग गरे र आफ्नो काममा निरन्तर **लगनशील** भए। यही लगनशीलता र अवसरको सदुपयोगले गर्दा उनको जन्मजात प्रतिभाले चम्कने मौका पायो। उनी एक महान् कलाकार बने, आफ्नो जीवनलाई सार्थक बनाए र आफ्नो कलामार्फत संसारमा परिवर्तन र चेतनाको ज्योति फैलाउन सफल भए। यसरी, यो वाक्यांशले हामीलाई के सिकाउँछ भने, यदि बालबालिकाको क्षमतालाई पहिचान गरी सही अवसर र प्रेरणा दिइयो भने उनीहरूले पनि पिकासोले जस्तै आफ्नो जीवन र संसारलाई उज्यालो बनाउन सक्छन्।\r\n\r\n**(ख) बन्दुकभन्दा कलम र कुची बलियो हुन्छ।**\r\n**प्रस्तुत सन्दर्भ:** यो शक्तिशाली वाक्यांश \'पाब्लो पिकासो\' जीवनी पाठबाट लिइएको हो। यसले भौतिक शक्ति (बन्दुक) र बौद्धिक तथा सिर्जनात्मक शक्ति (कलम र कुची) बिचको भिन्नता र श्रेष्ठतालाई प्रस्ट्याउँछ। पिकासोले आफ्नो कलामार्फत युद्ध र दमनको विरोध गरेको सन्दर्भमा यो वाक्यांश आएको हो।\r\n\r\n**विस्तृत व्याख्या:** \"बन्दुक\" हिंसा, विनाश र भौतिक शक्तिको प्रतीक हो, जसले मानिसमा डर र त्रास पैदा गर्छ तर मन र विचारलाई परिवर्तन गर्न सक्दैन। यसको प्रभाव क्षणिक हुन्छ। अर्कोतर्फ, \"कलम र कुची\" विचार, सिर्जना, चेतना र मानवताको प्रतीक हो। यसले मानिसको मानसिकता, हृदय र विचारमा गहिरो र दिगो परिवर्तन ल्याउन सक्छ।\r\n\r\nपरिवर्तनका लागि हतियारसहितको युद्ध मात्र आवश्यक हुँदैन; कला र साहित्यको बलबाट पनि ठुला क्रान्तिहरू सम्भव छन्। पिकासोले आफ्नो कलामार्फत शोषित, पीडित र सीमान्तकृत मानिसहरूका आवाजलाई बुलन्द गरे। उनको प्रसिद्ध चित्र \'द गुएर्निका\' युद्धको क्रूरता विरुद्धको एक शक्तिशाली अभिव्यक्ति हो। उनको कलाको शक्ति यति धेरै थियो कि नाजीहरूले समेत उनका चित्रदेखि डराएर जर्मनीमाथि प्रतिबन्ध लगाएका थिए। बन्दुकले धनजनको क्षति गर्छ र अशान्ति निम्त्याउँछ, तर कलम र कुचीले मानिसको मन जितेर शान्तिपूर्ण तरिकाले क्रान्ति सफल बनाउँछ। यसरी, यो वाक्यांशले के स्पष्ट पार्छ भने, भौतिक शक्तिभन्दा विचार र सिर्जनाको शक्ति धेरै गुणा बलियो र स्थायी हुन्छ।\r\n\r\n### ४. पाब्लो पिकासोले कलाकारिताको क्षेत्रमा पुऱ्याएका योगदानको चर्चा गर्नुहोस्।\r\n**उत्तर:** बीसौं शताब्दीका सबैभन्दा महान् र प्रभावशाली कलाकार पाब्लो पिकासोको कलाकारिताको क्षेत्रमा योगदान अविस्मरणीय र बहुआयामिक छ।\r\n\r\n**कलामा नयाँ वादको सुरुवात:** पिकासोको सबैभन्दा महत्त्वपूर्ण योगदान \'घनवाद\' (Cubism) को सुरुवात गर्नु हो। उनले वस्तुहरूलाई परम्परागत एउटै दृष्टिकोणबाट नहेरी विभिन्न कोणबाट एकैसाथ टुक्र्याएर देखाउने यो शैलीले विश्वकलामा क्रान्ति ल्यायो। यसले कलालाई हेर्ने र बुझ्ने दृष्टिकोणमा नै परिवर्तन ल्याइदियो।\r\n\r\n**विषयवस्तुको विविधता:** उनका कलाकृतिहरू विषयवस्तुको विविधताले भरिपूर्ण छन्। उनले आफ्नो जीवनका विभिन्न कालखण्ड (\'ब्लु पिरियड\', \'रोज पिरियड\') मा फरक-फरक विषयवस्तुलाई उठाए। \'ब्लु पिरियड\'मा उनले समाजका गरिब, दुःखी, बहिष्कृत र सीमान्तकृत मानिसहरूको पीडा र एक्लोपनलाई आफ्ना चित्रमा उतारे। \'रोज पिरियड\'मा उनले अलि आशावादी र प्रेमिल विषयवस्तुहरूलाई स्थान दिए।\r\n\r\n**युद्धविरोधी कला:** उनको चित्र \'द गुएर्निका\' लाई हालसम्मकै सबैभन्दा महान् युद्धविरोधी चित्र मानिन्छ। यस चित्रमार्फत उनले युद्धको त्रासदी र अमानवीयतालाई सशक्त रूपमा प्रस्तुत गरेका छन्। यसले कलालाई सामाजिक र राजनीतिक अभिव्यक्तिको एक शक्तिशाली माध्यमको रूपमा स्थापित गर्‍यो।\r\n\r\n**विशाल कला सिर्जना:** पिकासोले आफ्नो जीवनकालमा १३,५०० चित्र, १,२२८ मूर्तिकला, २,८८० सेरामिक कला, र लगभग १२,००० रेखाचित्रहरू सिर्जना गरे। यो विशाल सिर्जनाले उनलाई इतिहासकै सबैभन्दा prolific (प्रचुर सिर्जना गर्ने) कलाकारहरू मध्ये एक बनाउँछ।\r\n\r\n**विश्व कीर्तिमान:** उनका कलाकृतिहरू आज पनि संसारकै सबैभन्दा महँगा मानिन्छन्। सन् १९५५ मा बनाएको उनको तेल चित्र \'वुमन अफ अल्जियर्स\' ले विश्व कीर्तिमान कायम गरेको थियो।\r\n\r\n**निष्कर्ष:** यसरी, पिकासोले नयाँ कला शैलीको आविष्कार, विषयवस्तुको विविधता, कलामार्फत सामाजिक activitism, र विशाल कला सिर्जनामार्फत विश्व कलाको इतिहासमा आफ्नो नाम अजर र अमर बनाएका छन्।\r\n\r\n---\r\n\r\n## भाषिक संरचना र वर्णविन्यास (Linguistic Structure and Spelling)\r\n\r\n### १. दिइएको मुगु र पाल्पाको फोनमा भएको कुराकानीलाई अप्रत्यक्ष कथनमा परिवर्तन गर्नुहोस् :\r\n**उत्तर:**\r\n* मुगुले पाल्पालाई सन्चै हुनुहुन्छ भनेर सोध्यो।\r\n* पाल्पाले आफू सन्चै रहेको र मुगुलाई कस्तो छ भनेर सोध्यो।\r\n* मुगुले पनि आफू सन्चै रहेको बताउँदै पाल्पालाई अहिले के गर्दै हुनुहुन्छ भनेर सोध्यो।\r\n* पाल्पाले पाल्पाली ढाका बुन्दै गरेको बताउँदै मुगुलाई के गर्दै हुनुहुन्छ भनेर सोध्यो।\r\n* मुगुले राडीपाखी बुन्दै गरेको बतायो।\r\n* पाल्पाले मुगुका राडीपाखी राम्रा होलान् है भन्यो।\r\n* मुगुले पनि राम्रा रहेको र रारा घुम्न आई राडीपाखी लिएर जान भन्यो।\r\n* पाल्पाले आफू ढाकाका कपडा, ढाकाको टोपी, पछ्यौरा र चोली लिएर आउने कुरा बतायो।\r\n* मुगुले हुन्छ आउनू भन्दै पाल्पाका ढाकाका कपडा साह्रै मन पर्ने बतायो।\r\n* पाल्पाले हुन्छ भन्दै भेटमा थप कुरा गर्ने र अहिलेलाई फोन राख्ने प्रस्ताव गर्‍यो।\r\n* मुगुले हवस् भन्दै नमस्ते गर्‍यो।\r\n\r\n### २. दिइएको अनुच्छेदलाई शुद्ध गरी पुनर्लेखन गर्नुहोस् :\r\n**अशुद्ध:** ग्यानप्रसाद ज्ञालेन लिएर विग्यान ग्यवालीको पसलमा मटितेल लिन गएछन्। विग्यान सर भने गाडीको एसीमा ज्ञास सकिएर ज्ञारेजमा गएका रहेछन्। ... अग्यानी भइयो भने दुःख पाइन्छ।\r\n\r\n**शुद्ध:** **ज्ञान**प्रसाद **ग्यालेन** लिएर **विज्ञान** **ज्ञवाली**को पसलमा **मट्टितेल** लिन गएछन्। **विज्ञान** सर भने गाडीको एसीमा **ग्यास** सकिएर **ग्यारेज**मा गएका रहेछन्। ... **अज्ञानी** भइयो भने दुःख पाइन्छ।\r\n\r\n---\r\n\r\n## सिर्जना र परियोजना कार्य (Creative and Project Work)\r\n\r\n### १. दिइएका बुँदाका आधारमा मोतीराम भट्टको छोटो जीवनी तयार पार्नुहोस् :\r\n**युवाकवि मोतीराम भट्ट**\r\nमोतीराम भट्ट **युवाकवि**का रूपमा नेपाली साहित्यमा परिचित एक अमर नाम हो। उनी कवि, गजलकार, जीवनीकार र समालोचकका रूपमा परिचित एक **बहुमुखी व्यक्तित्व** थिए। उनको जन्म **वि.सं. १९२३ भाद्र** महिनामा काठमाडौँमा पिता दयाराम भट्ट र माता रिपुमर्दिनी देवीको कोखबाट भएको थियो।\r\n\r\nमोतीरामले फारसी, उर्दु, अङ्ग्रेजी, हिन्दी र संस्कृत भाषाको समेत ज्ञान हासिल गरेका थिए। उनको विवाह वि.सं. १९३७ मा भयो। उनलाई नेपाली साहित्यमा **गजल र समस्यापूर्ति कविताका आरम्भकर्ता**का रूपमा चिनिन्छ। उनले नै नेपालमा **छापाखाना स्थापना** गरी पत्रिका प्रकाशनको सुरुवात गरेका थिए। नेपाली साहित्यको श्रीवृद्धिका लागि उनले काठमाडौँ र बनारसमा **मोती मण्डली**को स्थापना गरे। उनको सबैभन्दा महत्त्वपूर्ण योगदान आदिकवि भानुभक्त आचार्यलाई खोजेर उनको **रामायणको बालकाण्ड प्रकाशन** गर्नु थियो।\r\n\r\nनेपाली साहित्यको उन्नयनमा आफूलाई समर्पित गरेका यी महान् साधकको **वि.सं. १९५३ मा ३० वर्षकै कलिलो उमेरमा देहावसान** भयो। छोटो जीवन बाँचे पनि नेपाली साहित्यमा उनले पुऱ्याएको अतुलनीय योगदानका कारण उनको नाम सधैँ अमर रहनेछ।', 1, '2025-07-25 01:11:38', '2025-09-16 03:05:11');
INSERT INTO `course_notes_content` (`id`, `topic_id`, `content`, `markdown_format`, `created_at`, `updated_at`) VALUES
(78, 11213, '# पख्नोस् - कक्षा १० (पूर्ण विस्तृत गाइड)\r\n\r\n\"पख्नोस्\" नेपाली हास्यव्यङ्ग्य निबन्ध साहित्यका सर्वोच्च प्रतिभा भैरव अर्यालद्वारा लिखित एक प्रसिद्ध निबन्ध हो। सामाजिक विषयवस्तुमा आधारित यस निबन्धमा मानिसको पर्खने र अनावश्यक पर्खाउने प्रवृत्तिप्रति चोटिलो व्यङ्ग्य गरिएको छ। यो विस्तृत गाइडले परीक्षाको तयारीका लागि सबै प्रश्नहरूको गहन र पूर्ण उत्तरहरू समावेश गर्दछ।\r\n\r\n---\r\n\r\n## शब्दभण्डार (Vocabulary)\r\n\r\n### १. दिइएका अनुकरणात्मक शब्द र कार्यबिच जोडा मिलाउनुहोस् :\r\n\r\n| **शब्द** | **कार्य** |\r\n| :--- | :--- |\r\n| ख्वाङख्वाङ | खोक्नु |\r\n| गजक्क | पर्नु |\r\n| ङिच्च | हाँस्नु |\r\n| लस्याङलुसुङ | गर्नु |\r\n| जम्स्याङजुम्सुङ | हुनु |\r\n\r\n### २. निबन्धबाट पारिभाषिक शब्द खोजी वाक्यमा प्रयोग गर्नुहोस् :\r\n* **सम्पादक:** मैले कान्तिपुर दैनिकको **सम्पादक**लाई चिठी लेख्छु।\r\n* **जमिनदार:** बुबा **जमिनदार** भएपछि छोरोलाई सम्पत्तिको चिन्ता हुँदैन।\r\n* **शिक्षित:** **शिक्षित** व्यक्ति भए सभ्य समाज बन्छ।\r\n* **लेख:** मेरो मामाले समसामयिक **लेख** लेख्नुहुन्छ।\r\n* **मनिटर:** कम्प्युटरको काम **मनिटर**मा डिस्प्ले हुन्छ।\r\n\r\n### ३. शिक्षा र वाणिज्य क्षेत्रका पारिभाषिक शब्दको अर्थ लेख्नुहोस् :\r\n**शिक्षा:**\r\n* **पाठ्यक्रम:** विद्यार्थीलाई सिकाउन बनाइएको विषयहरूको योजना।\r\n* **मूल्याङ्कन:** परीक्षार्थीहरूको विशेषता, स्तर आदि निर्धारण गर्ने काम।\r\n* **पुनर्बल:** काममा अझ सक्षम बनाउने अतिरिक्त सहयोग।\r\n* **पुस्तकालय:** पढ्नका लागि पुस्तकहरू राखिएको घर।\r\n* **शिक्षालय:** विद्यालय, पाठशाला।\r\n\r\n**वाणिज्य:**\r\n* **वासलात:** कुनै सङ्घसंस्थाको वर्षभरिको आम्दानी र खर्चको विवरण।\r\n* **भौचर:** बिक्री कारोबारमा नगद बुझाएको प्रमाणका रूपमा दिइने रसिद।\r\n* **फर्स्यौट:** लेनदेन हिसाब चुक्ता गर्ने काम।\r\n* **आयव्यय:** आम्दानी र खर्च।\r\n* **बेरुजु:** आर्थिक कारोबार जाँच्दा नमिलेको हिसाब।\r\n* **बजेट:** भविष्यमा हुने खर्च र आम्दानीको अनुमानित विवरण।\r\n* **निक्षेप:** बैङ्कको खातामा जम्मा गरिने रकम।\r\n\r\n### ४. निबन्धमा व्यङ्ग्य गर्ने क्रममा आएका टुक्कालाई अर्थ खुल्ने गरी वाक्यमा प्रयोग गर्नुहोस् :\r\n* **कन्सिरी तात्नु:** बिनसित्तिमा दोष लगाएपछि मेरो त **कन्सिरी तात्छ**।\r\n* **आगलागी हुनु:** तातोपानीले **आगलागी हुँदैन**।\r\n* **पानीमरुवा हुनु:** जायज कुरा गर्न पनि **पानीमरुवा हुनु** त भएन नि।\r\n* **जङ चल्नु:** **जङ चल्यो** भने एकैपटकमा म पाँच पिलेट मःमः खाइदिन्छु।\r\n* **दाउ हेर्नु:** ट्राफिक प्रहरी पनि घुम्तीमा **दाउ हेरेर** बस्छन्।\r\n\r\n---\r\n\r\n## बोध र अभिव्यक्ति (Comprehension and Expression)\r\n\r\n### १. दिइएका प्रश्नको उत्तर लेख्नुहोस् :\r\n\r\n**(क) \'पख्नोस्\' निबन्धको विषयवस्तुमाथि प्रकाश पार्नुहोस्।**\r\n**उत्तर:** \'पख्नोस्\' निबन्ध सामाजिक विषयवस्तुमा आधारित आत्मपरक निबन्ध हो। सामाजिक विसङ्गतिहरूमाथि शब्दवाण प्रहार गर्न सिपालु भैरव अर्यालले यस निबन्धमा मानवीय कमजोरीका रूपमा रहेको पर्खने र पर्खाउने विकृतिका विरुद्धमा व्यङ्ग्य प्रहार गरेका छन्। कोही पर्खन चाहँदैन तर सबै पर्खिरहेका छन्, पर्खाइरहेका छन् भन्ने कुरा निबन्धमा गरिएको छ। हरेक क्षेत्रमा पर्खने र पर्खाउने विकृति रहेको विषयवस्तु उल्लेख गर्दै निबन्धमा शिक्षितहरूमा झनै पर्खाउने प्रवृत्ति बढी रहेको विषयवस्तुको चर्चा गरिएको छ। यसरी \'पख्नोस्\' प्रवृत्ति व्यापक रहेको र यो प्रवृत्ति उन्नतिको बाधक भएको विषयवस्तु निबन्धमा चर्चा गरिएको छ।\r\n\r\n**(ख) \'सत्य, समता र शान्ति पख्दै आएको मानिस झन् विषमताको विषले बौलाहिरहेछ, अशान्त भइरहेछ।\' भन्नुको तात्पर्य के हो ?**\r\n**उत्तर:** यस भनाइको तात्पर्य हो कि मानिसको चाहना र वास्तविकताबीच ठुलो अन्तर छ। सबै मानिसको चाहना सत्य, समता र शान्ति हो, जसका लागि मानिसले युगौँदेखि पर्खँदै आएको छ। तर, जतिसुकै पर्खे पनि समताको साटो विषमता फैलिरहेको छ, र शान्तिको ठाउँमा अशान्ति छाइरहेको छ। आणविक हतियारमा प्रतिबन्ध लाग्नुपर्नेमा झन् निर्माण गर्ने होडबाजी चलेको छ। विज्ञानले भौतिक रूपमा धेरै उन्नति गरे पनि गाँस र बासजस्ता आधारभूत आवश्यकताका लागि मानिसले पर्खनुपर्ने अवस्था कायमै छ। यसरी, मानिसको चाहना र उसको काम गराइमा अन्तर भएका कारण चाहेको जस्तो आदर्श समाज निर्माण हुन सकेको छैन भन्नु नै प्रस्तुत भनाइको तात्पर्य हो।\r\n\r\n**(ग) निबन्धमा मानिसका कस्ता कमीकमजोरीप्रति व्यङ्ग्य गरिएको छ ?**\r\n**उत्तर:** यस निबन्धमा मानिसको पर्खने र अनावश्यक रूपमा पर्खाउने प्रवृत्तिप्रति चोटिलो व्यङ्ग्य गरिएको छ। आजका भनाउँदा मानिसहरू आफ्नो दायित्व र जिम्मेवारीप्रति सचेत छैनन्। उनीहरू कामलाई सधैँ कुराले टार्न खोज्छन्। सत्य र अहिंसाका आदर्श कुरा गर्छन्, तर व्यवहारमा असत्यको पक्ष लिँदै हिंसा मच्चाउन उद्यत रहन्छन्। आणविक हतियारमा प्रतिबन्ध लगाउनुपर्ने कुरा गर्छन्, तर त्यसलाई कार्यान्वयन गर्न लस्याङलुसुङ गर्छन्। अरूलाई बिनाकाम झुलाउन वा पर्खाउन पाउँदा आफूलाई महान् ठान्ने जस्ता मानवीय कमीकमजोरीप्रति निबन्धमा तिखो व्यङ्ग्य गरिएको छ।\r\n\r\n**(घ) यस निबन्धबाट कस्तो सन्देश पाउन सकिन्छ ?**\r\n**उत्तर:** भैरव अर्यालद्वारा लिखित \'पख्नोस्\' निबन्धले समयको महत्त्व बुझ्नुपर्छ र पर्खने तथा पर्खाउने जुम्सो प्रवृत्ति हटाउनुपर्छ भन्ने महत्त्वपूर्ण सन्देश दिएको छ। चिल्ला र शिष्ट शब्दहरू प्रयोग गरेर अरूलाई झुलाउने प्रवृत्ति झनै घातक हुन्छ। हामी आफ्नो कर्तव्य र दायित्वप्रति सदा सचेत रहनुपर्छ। अरूलाई झुलाएर आफूलाई महान् सिद्ध गर्ने प्रवृत्ति त्याग्नुपर्छ। हाम्रो विचार र कार्यमा समानता हुनुपर्छ। यो पृथ्वी सबै जीवहरूको साझा घर हो, त्यसैले यहाँ सञ्चालन हुने हरेक गतिविधि सबैको हितमा हुनुपर्छ। हामी सबै इमानदार, कर्तव्यनिष्ठ र विवेकशील बन्नुपर्छ भन्ने सन्देश यस निबन्धबाट पाउन सकिन्छ।\r\n\r\n### २. व्याख्या गर्नुहोस् :\r\n\r\n**(क) सबै पर्खाइको पछिल्तिर मेरा सयौँ सपना पर्खिरहेछन्, इच्छा र आकाङ्क्षा पर्खिरहेछन्।**\r\n**प्रस्तुत सन्दर्भ:** प्रस्तुत निबन्धांश प्रभावशाली हास्यव्यङ्ग्य निबन्धकार भैरव अर्यालको \'पख्नोस्\' शीर्षकको निबन्धबाट साभार गरिएको हो। पर्खने र पर्खाउने प्रवृत्तिले व्यक्तिको भविष्य कसरी अन्योलपूर्ण र सपनाहरू अधुरै रहन्छन् भन्ने कुरा बुझाउने सन्दर्भमा यो अंश आएको हो।\r\n\r\n**विस्तृत व्याख्या:** मानिसले जीवनमा अनेकौँ सपना, इच्छा र आकाङ्क्षाहरू देखेको हुन्छ। ती सपनाहरूलाई साकार पार्न ऊ कर्मशील बन्नुपर्छ। तर, काम गर्नुको साटो कुराले टार्ने र जताततै पर्खनुपर्ने सामाजिक विकृतिका कारण उसका सपनाहरू पूरा हुन सकेका छैनन्। निबन्धकारले आफूले थाहा पाएदेखि हरेक क्षेत्रमा पर्खनुपरेको गुनासो व्यक्त गर्दछन्। जागिर पाउने आश्वासनदेखि तलब पाउने दिनसम्म, र उपचारकदेखि लुगा सिउने सूचीकारसम्म सबैलाई पर्खनुपरेको छ।\r\n\r\nयो निरन्तरको पर्खाइले मानिसलाई जुम्सो र निष्क्रिय बनाएको छ। ऊ केही गरूँ, केही बनूँ भन्ने सोचले अघि बढ्छ, तर हरेक मोडमा \'पख्नोस्\' भन्ने शब्दले उसको गतिलाई रोकिदिन्छ। समयमा काम नगर्ने यही प्रवृत्तिले गर्दा व्यक्तिका सयौँ सपना, इच्छा र आकाङ्क्षाहरू केवल पर्खाइमै सीमित रहन पुगेका छन्। विशेषगरी, शिक्षित मानिसहरूले नै सभ्य र शिष्ट शब्द प्रयोग गरेर अरूलाई झुलाउने काम गरिरहेका छन्, जसले यो समस्यालाई झनै विकराल बनाएको छ। यसरी, यो निबन्धांशले पर्खाउने विकृतिले कसरी व्यक्तिको सिर्जनात्मकता र प्रगतिलाई मार्दछ भन्ने यथार्थलाई मार्मिक रूपमा प्रस्तुत गरेको छ।\r\n\r\n**(ख) हामी दुवै चाहन्छौँ एउटा त्यस्तो दुनियाँ सिर्जना गरौँ जहाँ कसैले कसैलाई कुराले मात्र टार्न नसकोस् !**\r\n**प्रस्तुत सन्दर्भ:** यो निबन्धांश नेपाली हास्यव्यङ्ग्य निबन्धका सुप्रसिद्ध स्रष्टा भैरव अर्यालको \'पख्नोस्\' निबन्धबाट उद्धृत गरिएको हो। पर्खने र पर्खाउने दुवै परम्पराको अन्त्य भई समयमै काम हुने आदर्श समाजको चाहना व्यक्त गर्ने क्रममा यो अंश आएको हो।\r\n\r\n**विस्तृत व्याख्या:** मानिसमा अनेक कमजोरी छन्, जसमध्ये काम गर्नेभन्दा कुराले टारेर अरूलाई झुलाइरहने प्रवृत्ति एक प्रमुख हो। यसैका कारण मानिसले समयलाई अर्थहीन रूपमा बिताइरहेको छ र उसको सिर्जना शक्ति हराउँदै गएको छ। मानिस जुम्राजस्तै जुम्सो बनेको छ र हरेक काममा लस्याङलुसुङ पारा देखाउँछ। शिक्षित व्यक्तिहरूमा त यस्तो प्रवृत्ति झनै बढी देखिन्छ।\r\n\r\nयस्तो अवस्थामा, निबन्धकारले पाठक र आफूबीच एक साझा चाहना व्यक्त गर्छन्—एउटा यस्तो दुनियाँको सिर्जना, जहाँ कसैले कसैलाई चिल्ला कुराले मात्र टार्न नसकोस्। यो एउटा यस्तो आदर्श समाजको परिकल्पना हो, जहाँ कामको सम्मान हुन्छ, समयको महत्त्व हुन्छ र मानिसहरू आफ्नो जिम्मेवारीप्रति इमानदार हुन्छन्। यो दुनियाँमा सबैले उन्नति र प्रगति नै चाहन्छन्। तसर्थ, जागरुकताका साथ काम सम्पन्न गरी अगाडि बढ्ने वातावरण सिर्जना गर्नुपर्छ। यस्तो ढिलासुस्ती र पर्खाउने प्रवृत्तिको अन्त्य गर्नु नै सबैको हितमा हुन्छ। यसरी, निबन्धकारले सरल भाषाशैलीमार्फत सबैको चाहना ढिलासुस्ती हटाउने भए पनि पर्खनुपर्ने बाध्यता कायमै रहेको यथार्थलाई अभिव्यक्त गरेका छन्।\r\n\r\n### ३. \'पख्नोस्\' निबन्धमा हाम्रो समाजका कस्ता पक्षमाथि व्यङ्ग्य गरिएको छ, समीक्षा गर्नुहोस्।\r\n**उत्तर:** भैरव अर्यालद्वारा लिखित \'पख्नोस्\' निबन्धले हाम्रो समाजमा व्याप्त \'पर्खने र पर्खाउने\' प्रवृत्तिमाथि गहिरो र तिखो व्यङ्ग्य गरेको छ।\r\n**कामभन्दा कुरालाई प्राथमिकता दिने प्रवृत्ति:** निबन्धमा मानिसहरू आफ्नो जिम्मेवारी इमानदारीसाथ पूरा गर्नुको सट्टा कुराले टारेर आफूलाई महान् ठान्ने प्रवृत्तिमाथि व्यङ्ग्य गरिएको छ। मानौं, मानिसहरूबीच एकअर्कालाई झुलाउने प्रतिस्पर्धा नै चलिरहेको छ।\r\n**शिक्षित वर्गको आडम्बर:** सामान्य मानिसभन्दा शिक्षित वर्गमा यो प्रवृत्ति झनै बढी देखिन्छ। उनीहरू सभ्य र चिल्ला शब्दहरूको प्रयोग गरेर अरूलाई पर्खाउन झनै निपुण छन्, जसले गर्दा उनीहरूको आडम्बर र खोक्रोपनमाथि व्यङ्ग्य गरिएको छ।\r\n**निष्क्रियता र जुम्सोपन:** पर्खँदा-पर्खँदै मानिसको काम गर्ने इच्छाशक्ति र जोस-जाँगर हराएको छ, जसले गर्दा ऊ जुम्राजस्तै जुम्सो र हरेक काममा लम्स्याङलुसुङ गर्ने भएको छ। यो सामाजिक निष्क्रियतामाथि निबन्धले प्रहार गरेको छ।\r\n**विचार र व्यवहारमा भिन्नता:** मानिसहरू सत्य, समता र शान्तिका ठुला-ठुला कुरा गर्छन्, तर व्यवहारमा विषमता र अशान्ति फैलाइरहेका छन्। आणविक हतियारमा प्रतिबन्ध लगाउनुपर्छ भन्ने तर त्यसका लागि कुनै ठोस कदम नचाल्ने पाखण्डीपनमाथि पनि व्यङ्ग्य गरिएको छ।\r\n**पर्खाइको सर्वव्यापकता:** जन्मेदेखि मृत्युसम्म, र सामान्य घरायसी कामदेखि राष्ट्रिय तथा अन्तर्राष्ट्रिय मुद्दाहरूसम्म, पर्खाइ सर्वव्यापी छ। यो पर्खाइ हाम्रो नियति नै बनिसकेको छ, जसले गर्दा मानिसका हजारौँ सपना र आकाङ्क्षाहरू मरिरहेका छन्।\r\n\r\n**निष्कर्ष:** समग्रमा, यो निबन्धले हाम्रो समाजमा रहेको ढिलासुस्ती, आडम्बर, निष्क्रियता, र विचार-व्यवहार बीचको खाडल जस्ता पक्षहरूमाथि चोटिलो व्यङ्ग्य गरेको छ।\r\n\r\n---\r\n\r\n## भाषिक संरचना र वर्णविन्यास (Linguistic Structure and Spelling)\r\n\r\n### १. दिइएका वाक्यको वचन, पुरुष, लिङ्ग र आदर भर्नुहोस् :\r\n\r\n| **वाक्य** | **वचन** | **पुरुष** | **लिङ्ग** | **आदर** |\r\n| :--- | :--- | :--- | :--- | :--- |\r\n| तैँले पाठ पढिस्। | एकवचन | द्वितीय | स्त्री/पुलिङ्ग | सामान्य |\r\n| ऊ घर जान्छ। | एकवचन | तृतीय | पुलिङ्ग | सामान्य |\r\n| रमा घर जान्छे। | एकवचन | तृतीय | स्त्रीलिङ्ग | सामान्य |\r\n| उहाँ धनकुटा जानुहुन्छ। | एकवचन | तृतीय | स्त्री/पुलिङ्ग | उच्च |\r\n| म खेल खेल्छु। | एकवचन | प्रथम | स्त्री/पुलिङ्ग | - |\r\n| हामीहरू रारा पुग्यौँ। | बहुवचन | प्रथम | स्त्री/पुलिङ्ग | - |\r\n\r\n### २. दिइएको अनुच्छेदका वाक्यको क्रियापद सच्याएर पदसङ्गति मिलाई लेख्नुहोस् :\r\n**अशुद्ध:** कक्षाका साथीहरू वनभोज गएछ। सीता र रीता वनभोज गइन्छ। गीता चाहि गएछ। बुबाले सबैलाई वनभोज जान अनुमति दिएछ। ... आमाले तँ चाँडै आउ र बेलुकी घुम्न जाऔंला भनिछन्।\r\n\r\n**शुद्ध:** कक्षाका साथीहरू वनभोज **गएछन्**। सीता र रीता वनभोज **गएनछन्**। गीता चाहि **गइछ**। बुबाले सबैलाई वनभोज जान अनुमति **दिनुभएछ**। ... आमाले **तिमी** चाँडै आउ र बेलुकी घुम्न जाऔंला **भन्नुभएछ**।\r\n\r\n### ३. दिइएको सङ्केतअनुसार पदसङ्गति मिल्ने क्रियापद भर्नुहोस् :\r\n* **(क) पारस पाण्डे एयरपोर्ट पुगेछन्। (उच्च आदर)**\r\n    * **उत्तर:** पारस पाण्डे एयरपोर्ट **पुग्नुभएछ**।\r\n* **(ख) खटपटानन्द खतिवडा खेततिर झरेछ। (सामान्य आदर)**\r\n    * **उत्तर:** खटपटानन्द खतिवडा खेततिर **झरेछन्**।\r\n* **(ग) ऊ घरतिर हिँडी। (मध्यम आदर)**\r\n    * **उत्तर:** उनी घरतिर **हिँडिन्**।\r\n* **(घ) उनी पाठ पढिछन्। (द्वितीय पुरुष, सामान्य आदर)**\r\n    * **उत्तर:** तैँले पाठ **पढिछस्**।\r\n* **(ङ) भोलि आउने छ। (प्रथम पुरुष, स्त्रीलिङ्ग)**\r\n    * **उत्तर:** म भोलि आउने **छु**।\r\n* **(च) उनी भोलि आउने छन्। (स्त्रीलिङ्ग)**\r\n    * **उत्तर:** उनी भोलि आउने **छिन्**।\r\n\r\n### ४. हलन्त र अजन्तको उपयुक्त प्रयोग गरी दिइएको अनुच्छेद पुनर्लेखन गर्नुहोस् :\r\n**अशुद्ध:** तैंले के गरिस भनेर् मलाई साथीले सोध्यो। मैले गृहकार्य गरेँ भनेपछि उस्ले मलाई भन्यो, अब म पनि गृहकार्य गर्छु। तँ पनि गृहकार्य गर। उमेश, रमेश, श्यामले पनि गृहकार्य सकेछन।\r\n\r\n**शुद्ध:** तैँले के **गरिस्** भनेर मलाई साथीले सोध्यो। मैले गृहकार्य **गरें** भनेपछि **उसले** मलाई भन्यो, अब म पनि गृहकार्य गर्छु। तँ पनि गृहकार्य **गर्**। उमेश, रमेश, श्यामले पनि गृहकार्य **सकेछन्**।', 1, '2025-07-25 01:11:38', '2025-09-16 03:05:11'),
(79, 11201, '# उज्यालो यात्रा - कक्षा १० (पूर्ण विस्तृत गाइड)\r\n\r\n\"उज्यालो यात्रा\" एक प्रेरणादायी कविता हो जसले सामाजिक रूपान्तरण, एकता र उज्ज्वल भविष्यको चाहनालाई सशक्त रूपमा प्रस्तुत गर्दछ। यसले समाजमा व्याप्त अन्धविश्वास, रूढिवादी सोच र विभेदहरूलाई हटाएर समानता र प्रगतिको नयाँ बिहानी ल्याउने अठोट व्यक्त गर्दछ। यो विस्तृत गाइडले परीक्षाको तयारीका लागि सबै प्रश्नहरूको गहन र पूर्ण उत्तरहरू समावेश गर्दछ।\r\n\r\n---\r\n\r\n## शब्दभण्डार (Vocabulary)\r\n\r\n### १. दिइएका शब्द र अर्थबिच जोडा मिलाउनुहोस् :\r\n\r\n| **शब्द** | **अर्थ** |\r\n| :--- | :--- |\r\n| सिर्जना | रचना, बनावट |\r\n| विभेद | भेदभाव, भिन्नता |\r\n| रूढिग्रस्त | पुरानो परम्परामा बाँधिएको |\r\n| कुरीति | नराम्रो चलन, कुसंस्कार |\r\n| अड्चन | बाधा, रोकावट |\r\n| यात्रा | एक ठाउँबाट अर्को ठाउँमा जाने काम |\r\n| गन्तव्य | पुग्नुपर्ने ठाउँ, लक्ष्य |\r\n\r\n### २. दिइएका शब्दलाई वाक्यमा प्रयोग गर्नुहोस् :\r\n* **अन्धविश्वास:** समाजमा रहेको **अन्धविश्वास** नै प्रगतिको सबैभन्दा ठुलो बाधक हो।\r\n* **उन्नति:** देशको **उन्नति**का लागि सबै नागरिक एकजुट हुनुपर्छ।\r\n* **सौन्दर्य:** नेपालको प्राकृतिक **सौन्दर्य** विश्वभरि नै प्रसिद्ध छ।\r\n* **सद्भाव:** हाम्रो देशमा विभिन्न जातजाति र धर्महरूबीच गहिरो **सद्भाव** रहेको छ।\r\n* **सङ्कल्प:** हामी सबैले देशलाई समृद्ध बनाउने **सङ्कल्प** लिनुपर्छ।\r\n* **माला:** कविले सबै नेपालीलाई एकताको **माला**मा गाँस्ने कुरा गरेका छन्।\r\n\r\n### ३. उखान र टुक्कामा के फरक छ, उदाहरणसहित लेख्नुहोस् :\r\n**उखान:** लामो समयदेखि चल्दै आएको, विशेष अर्थ दिने, अनुభవसिद्ध र सारगर्भित भनाइलाई उखान भनिन्छ। यो पूर्ण वाक्य हुन्छ र यसले प्रेरणा वा सन्देश दिन्छ।\r\n* **उदाहरण:** \"अकबरी सुनलाई कसी लाउनु पर्दैन\" र \"जसले मह काढ्छ, उसले हात चाट्छ\"।\r\n\r\n**टुक्का:** कुनै पनि भाषामा विशेष अर्थ दिने शब्द वा शब्दहरूको समूहलाई टुक्का भनिन्छ। यो अपूर्ण वाक्य हुन्छ र यसले लाक्षणिक अर्थ दिन्छ।\r\n* **उदाहरण:** \"कानमा तेल हाल्नु\" (बेवास्ता गर्नु) र \"कम्मर कस्नु\" (तयार हुनु)।\r\n\r\n---\r\n\r\n## बोध र अभिव्यक्ति (Comprehension and Expression)\r\n\r\n### १. दिइएका प्रश्नको उत्तर लेख्नुहोस् :\r\n\r\n**(क) कविले कवितामा सामाजिक रूपान्तरणको चाहनालाई कसरी व्यक्त गरेका छन् ?**\r\n**उत्तर:** कविले \"उज्यालो यात्रा\" कवितामा सामाजिक रूपान्तरणको गहिरो चाहना व्यक्त गरेका छन्। उनले समाजमा व्याप्त रूढिग्रस्त सोचाइ, अन्धविश्वास, कुरीति र विभेदहरूलाई जरैदेखि उखेलेर फाल्ने सङ्कल्प गरेका छन्। कविले सबै जातजाति, भाषाभाषी र संस्कृतिलाई एकताको मालामा गाँसेर एउटा सुन्दर र समतामूलक समाजको सिर्जना गर्ने इच्छा राखेका छन्। उनले मानवताको गीत गाउँदै, माया र सद्भावको फूल फुलाउँदै एउटा यस्तो नयाँ संसार बसाल्न चाहेका छन्, जहाँ कुनै पनि प्रकारको अन्याय र असमानता हुनेछैन। यसरी, कविले नकारात्मक पक्षहरूको अन्त्य र सकारात्मक पक्षहरूको निर्माणमार्फत सामाजिक रूपान्तरणको चाहनालाई सशक्त रूपमा व्यक्त गरेका छन्।\r\n\r\n**(ख) \'उज्यालो यात्रा\' मा के-कस्ता बाधा अड्चन आउन सक्छन् भनिएको छ ?**\r\n**उत्तर:** कविताअनुसार \'उज्यालो यात्रा\' अर्थात् सामाजिक रूपान्तरणको यात्रामा अनेकौँ बाधा र अड्चनहरू आउन सक्छन्। समाजमा गहिरोसँग जरो गाडेर बसेका **रूढिग्रस्त सोचाइ** र **अन्धविश्वास** नै सबैभन्दा ठुला बाधाहरू हुन्। मानिसहरूमा रहेको **विभेदकारी भावना**, **कुरीति** र **कुसंस्कारहरू**ले पनि यो यात्रालाई कठिन बनाउँछन्। यी बाधाहरूले मानिसहरूलाई एक हुन दिँदैनन् र प्रगतिको मार्गलाई अवरुद्ध गर्छन्। कवि यी सबै बाधा र अड्चनहरूसित कहिल्यै नझुक्ने र तिनलाई परास्त गरेरै आफ्नो गन्तव्यमा पुग्ने दृढ सङ्कल्प व्यक्त गर्दछन्।\r\n\r\n**(ग) \'उज्यालो यात्रा\' कविताको मुख्य सन्देश के हो ?**\r\n**उत्तर:** \"उज्यालो यात्रा\" कविताको मुख्य सन्देश **एकता, सङ्कल्प र निरन्तरको प्रयासबाट मात्रै सामाजिक रूपान्तरण सम्भव छ** भन्ने हो। कविताले हामीलाई समाजमा व्याप्त अन्धविश्वास, कुरीति, विभेद र असमानता जस्ता नकारात्मक पक्षहरूविरुद्ध एकजुट भएर लड्न प्रेरित गर्दछ। यसले हामीलाई सिकाउँछ कि जस्तोसुकै बाधा र अड्चन आए पनि हामी आफ्नो लक्ष्यबाट विचलित हुनुहुँदैन। माया, सद्भाव र मानवताको जगमा मात्रै एउटा सुन्दर, शान्त र समृद्ध समाजको निर्माण हुन सक्छ। तसर्थ, उज्ज्वल भविष्यको लागि निरन्तर अघि बढिरहनु र कहिल्यै हार नमान्नु नै यस कविताको मूल सन्देश हो।\r\n\r\n### २. व्याख्या गर्नुहोस् :\r\n\r\n**(क) बाधा र अड्चनसित अब कहिल्यै नझुक्ने गरी**\r\n**सिर्जनाको एउटा सुन्दर बगैँचा सजाउनलाई ।**\r\n**प्रस्तुत सन्दर्भ:** यो कवितांश \"उज्यालो यात्रा\" शीर्षकको कविताबाट साभार गरिएको हो। यसमा कविले सामाजिक रूपान्तरणको कठिन यात्रामा आउने चुनौतीहरूको सामना गर्ने दृढ सङ्कल्प र भविष्यको सुन्दर परिकल्पनालाई व्यक्त गरेका छन्।\r\n\r\n**विस्तृत व्याख्या:** यस अंशमा कविले सामाजिक परिवर्तनको यात्रालाई सहज नभएको स्वीकार गरेका छन्। उनलाई थाहा छ कि यो यात्रामा अनेकौँ \'बाधा र अड्चन\'हरू आउनेछन्, जुन समाजमा व्याप्त रूढिवादी सोच, अन्धविश्वास र कुरीतिहरूका प्रतीक हुन्। तर, कवि यी चुनौतीहरूसँग \'कहिल्यै नझुक्ने\' अठोट व्यक्त गर्छन्। उनको यो सङ्कल्पले एक क्रान्तिकारी र दृढ भावनालाई दर्शाउँछ।\r\n\r\nउनको यो सङ्घर्षको अन्तिम लक्ष्य भनेको \'सिर्जनाको एउटा सुन्दर बगैँचा सजाउनु\' हो। यहाँ \'सुन्दर बगैँचा\' एउटा रूपक हो, जसले विविधतामा एकता भएको, समानता, न्याय र सद्भावले भरिपूर्ण एक आदर्श समाजलाई सङ्केत गर्दछ। जसरी बगैँचामा विभिन्न रङ र प्रकारका फूलहरू मिलेर एउटा सुन्दर दृश्य सिर्जना गर्छन्, त्यसरी नै कविले पनि विभिन्न जातजाति र संस्कृतिहरू मिलेर बनेको एक सामञ्जस्यपूर्ण समाजको कल्पना गरेका छन्। तसर्थ, यो कवितांशले नकारात्मकतालाई परास्त गर्ने दृढता र सकारात्मक भविष्य निर्माण गर्ने सुन्दर सपनालाई एकैसाथ प्रस्तुत गरेको छ।\r\n\r\n**(ख) एउटा सुन्दर संसार बसाल्नलाई**\r\n**नौलो घाम र नौला गीतहरू गाउनलाई ।**\r\n**प्रस्तुत सन्दर्भ:** यो कवितांश \"उज्यालो यात्रा\" कविताबाट लिइएको हो, जसमा कविले आफ्नो यात्राको अन्तिम लक्ष्य र त्यसबाट प्राप्त हुने सुखद परिणामको चित्रण गरेका छन्।\r\n\r\n**विस्तृत व्याख्या:** यस अंशमा कविको \'उज्यालो यात्रा\' को अन्तिम गन्तव्य स्पष्ट रूपमा देखाइएको छ, जुन हो—\'एउटा सुन्दर संसार बसाल्नु\'। यो \'सुन्दर संसार\' भनेको भौतिक रूपमा मात्र सुन्दर नभई सामाजिक, सांस्कृतिक र भावनात्मक रूपमा पनि सुन्दर भएको समाज हो। यो एउटा यस्तो संसार हो, जहाँ विभेद, अन्याय, गरिबी र अन्धविश्वास जस्ता कुनै पनि कुरूपताहरू छैनन्, बरु माया, सद्भाव र समानता मात्र छ।\r\n\r\nयो सुन्दर संसारको आगमनलाई \'नौलो घाम\' ले प्रतीकका रूपमा प्रस्तुत गरेको छ। \'नौलो घाम\' नयाँ युग, नयाँ चेतना र नयाँ बिहानीको प्रतीक हो। यसले अज्ञानताको अन्धकारलाई चिरेर ज्ञान र प्रगतिको उज्यालो ल्याउने सङ्केत गर्दछ। जब यस्तो नयाँ बिहानी आउँछ, तब मानिसहरूले \'नौला गीतहरू\' गाउनेछन्। यी \'नौला गीतहरू\' खुसी, स्वतन्त्रता र सफलताको उत्सवका प्रतीक हुन्। यी गीतहरूले पुरानो युगको पीडालाई बिर्साएर नयाँ युगको आनन्दलाई अभिव्यक्त गर्नेछन्। यसरी, यो कवितांशले एक आदर्श र सुन्दर भविष्यको आशावादी चित्र प्रस्तुत गरेको छ, जुन सकारात्मक परिवर्तनका लागि गरिने सङ्घर्षको अन्तिम पुरस्कार हो।\r\n\r\n---\r\n\r\n## भाषिक संरचना र वर्णविन्यास (Linguistic Structure and Spelling)\r\n\r\n### १. दिइएका वाक्यमा प्रयोग भएका नामयोगी पहिचान गरी लेख्नुहोस् :\r\n* **(क) तिमी**भन्दा **म जेठो छु।**\r\n    * **उत्तर:** भन्दा\r\n* **(ख) घर**सम्म **पुग्न खोला तर्नुपर्छ।**\r\n    * **उत्तर:** सम्म\r\n* **(ग) हामी खोला**तिर **गयौँ।**\r\n    * **उत्तर:** तिर\r\n* **(घ) खोला**माथि **पुल छ।**\r\n    * **उत्तर:** माथि\r\n\r\n### २. दिइएका नामयोगीलाई वाक्यमा प्रयोग गर्नुहोस् :\r\n* **अनुसार:** नियम**अनुसार** काम गर्नुपर्छ।\r\n* **भरि:** दिन**भरि** काम गरेर ऊ थाकेको थियो।\r\n* **देखि:** म भोलि**देखि** नियमित व्यायाम गर्नेछु।\r\n* **तिर:** उनीहरू घर**तिर** लागे।\r\n* **मुनि:** बिरालो टेबल**मुनि** लुकेर बसेको छ।\r\n\r\n### ३. नामयोगी र क्रियायोगीबिचको भिन्नता उदाहरणसहित लेख्नुहोस् :\r\n**नामयोगी:** नाम वा सर्वनाम शब्दको पछाडि जोडिएर आउने अव्यय शब्दलाई नामयोगी भनिन्छ। यिनीहरूले वाक्यमा अन्य शब्दसँग सम्बन्ध देखाउँछन्।\r\n* **उदाहरण:** घर**भित्र** बिरालो छ। (यहाँ \'भित्र\' नामयोगी हो किनभने यो \'घर\' नामसँग जोडिएर आएको छ।)\r\n\r\n**क्रियायोगी:** क्रिया वा विशेषणको विशेषता जनाउने शब्दलाई क्रियायोगी भनिन्छ। यिनीहरू छुट्टै लेखिन्छन्।\r\n* **उदाहरण:** बिरालो **भित्र** पस्यो। (यहाँ \'भित्र\' क्रियायोगी हो किनभने यसले \'पस्यो\' क्रियाको विशेषता जनाएको छ र छुट्टै लेखिएको छ।)\r\n\r\n### ४. दिइएको अनुच्छेदबाट सुरु, बिच र अन्तिममा ह्रस्व इकार प्रयोग भएका शब्दको सूची बनाउनुहोस् :\r\n* **सुरुमा ह्रस्व इकार:** किताब, मिलाई, निम्ति, सिपालु, भिजाइ\r\n* **बिचमा ह्रस्व इकार:** साहित्य, कविता, आखिर, शनिबार, अहिले\r\n* **अन्तिममा ह्रस्व इकार:** कवि, अनि, पनि, प्रति, अघि\r\n\r\n---\r\n\r\n## सिर्जना र परियोजना कार्य (Creative and Project Work)\r\n\r\n### १. \'मेरो सपनाको नेपाल\' शीर्षकमा एउटा कविता रचना गर्नुहोस्।\r\n\r\n**मेरो सपनाको नेपाल**\r\n\r\nहिमाल हाँसेको, पहाड नाचेको,\r\nतराईमा खुसीको धान झुलेको,\r\nसबै नेपालीको मन मिलेको,\r\nमेरो सपनाको नेपाल।\r\n\r\nनहोस् जहाँ कुनै जातको भेद,\r\nनहोस् जहाँ कुनै धर्मको खेद,\r\nमानवताकै लेखिएको होस् वेद,\r\nमेरो सपनाको नेपाल।\r\n\r\nभ्रष्टाचार र अन्याय हटेको,\r\nसबैको अनुहारमा हाँसो डटेको,\r\nगरिबीको बादल फाटेको,\r\nमेरो सपनाको नेपाल।\r\n\r\nज्ञान र विज्ञानको उज्यालो छाएको,\r\nहरेक युवाले स्वदेशमै काम पाएको,\r\nसबैले एकताको गीत गाएको,\r\nमेरो सपनाको नेपाल।', 1, '2025-07-25 01:11:38', '2025-09-16 03:05:11'),
(80, 11406, '# Electricity and Magnetism - Grade 10 (SEE) Physics\r\n## Complete Topper Level Notes - NEB Curriculum 2080\r\n\r\n---\r\n\r\n## 🎯 Chapter Overview\r\n**Chapter 6: Electricity and Magnetism** is one of the most important chapters in Grade 10 Physics for SEE examination. This chapter covers fundamental concepts of electric current, magnetic fields, electromagnetic induction, and their practical applications.\r\n\r\n**Weightage:** 15-20 marks in SEE examination\r\n**Time Required:** 25-30 periods\r\n\r\n---\r\n\r\n## 📚 Learning Objectives\r\nAfter studying this chapter, students will be able to:\r\n- Understand electric current and its effects\r\n- Explain magnetic fields and their properties\r\n- Analyze electromagnetic induction phenomena\r\n- Apply concepts in practical devices like motors, generators, and transformers\r\n\r\n---\r\n\r\n## ⚡ 1. ELECTRIC CURRENT\r\n\r\n### 1.1 Definition\r\nElectric current is the flow of electric charges (electrons) through a conductor per unit time.\r\n\r\n**Formula:** \r\n```\r\nI = Q/t\r\nWhere: I = Current (Ampere), Q = Charge (Coulomb), t = Time (Second)\r\n```\r\n\r\n**SI Unit:** Ampere (A)\r\n- 1 Ampere = 1 Coulomb/1 Second\r\n- 1 mA = 10⁻³ A\r\n- 1 μA = 10⁻⁶ A\r\n\r\n### 1.2 Types of Current\r\n\r\n#### A. Direct Current (DC)\r\n- Current flows in one direction only\r\n- Constant magnitude and direction\r\n- Sources: Battery, DC generator, solar cells\r\n- Used in: Electronic devices, mobile phones, laptops\r\n\r\n#### B. Alternating Current (AC)  \r\n- Current changes direction periodically\r\n- Magnitude and direction vary sinusoidally\r\n- Frequency in Nepal: 50 Hz (changes direction 100 times per second)\r\n- Sources: AC generator, power stations\r\n- Used in: Household appliances, industrial equipment\r\n\r\n### 1.3 Effects of Electric Current\r\n\r\n#### 1. Heating Effect\r\n- When current passes through a conductor, it heats up\r\n- Electrical energy converts to heat energy\r\n- **Applications:** Electric heater, iron, toaster, bulb filament\r\n- **Formula:** H = I²Rt (Joule\'s Law)\r\n\r\n#### 2. Magnetic Effect\r\n- Current-carrying conductor behaves like a magnet\r\n- Creates magnetic field around the conductor\r\n- **Applications:** Electromagnet, electric bell, motor, generator\r\n\r\n#### 3. Chemical Effect\r\n- Current can cause chemical changes in electrolytes\r\n- **Applications:** Electroplating, electrolysis, battery charging\r\n\r\n---\r\n\r\n## 🧲 2. MAGNETISM\r\n\r\n### 2.1 Magnetic Field\r\nThe space around a magnet where its magnetic influence can be felt.\r\n\r\n**Properties of Magnetic Field Lines:**\r\n- They form closed loops\r\n- Never intersect each other\r\n- Density indicates field strength\r\n- Direction: North to South (outside magnet)\r\n\r\n**SI Unit:** Tesla (T) or Weber/m²\r\n- 1 Tesla = 10⁴ Gauss\r\n\r\n### 2.2 Magnetic Field due to Current\r\n\r\n#### Oersted\'s Discovery (1820)\r\nDanish physicist Hans Christian Oersted discovered that electric current produces magnetic field.\r\n\r\n#### Right Hand Thumb Rule\r\nIf the thumb of right hand points in the direction of current, then the curled fingers show the direction of magnetic field lines.\r\n\r\n#### Magnetic Field Formulas\r\n\r\n**1. Straight Current-Carrying Conductor:**\r\n```\r\nB = (μ₀I)/(2πr)\r\nWhere: μ₀ = 4π × 10⁻⁷ T⋅m/A (permeability of free space)\r\n       I = Current, r = distance from conductor\r\n```\r\n\r\n**2. Circular Current-Carrying Coil (at center):**\r\n```\r\nB = (μ₀I)/(2r)\r\nWhere: r = radius of coil\r\n```\r\n\r\n**3. Solenoid (inside):**\r\n```\r\nB = μ₀nI\r\nWhere: n = number of turns per unit length (N/l)\r\n```\r\n\r\n### 2.3 Force on Current-Carrying Conductor\r\n\r\nWhen a current-carrying conductor is placed in a magnetic field, it experiences a force.\r\n\r\n**Formula:**\r\n```\r\nF = BIL sin θ\r\nWhere: B = Magnetic field, I = Current, L = Length of conductor\r\n       θ = angle between current and magnetic field\r\n```\r\n\r\n**Fleming\'s Left Hand Rule:**\r\n- **Thumb:** Direction of force (motion)\r\n- **First finger:** Direction of magnetic field\r\n- **Middle finger:** Direction of current\r\n\r\n---\r\n\r\n## 🔄 3. ELECTROMAGNETIC INDUCTION\r\n\r\n### 3.1 Faraday\'s Law of Electromagnetic Induction\r\n\r\n**Statement:** \"Whenever there is a change in magnetic flux linked with a closed circuit, an EMF is induced in the circuit.\"\r\n\r\n**Mathematical Form:**\r\n```\r\nε = -dΦ/dt = -N(dΦ/dt)\r\nWhere: ε = induced EMF, Φ = magnetic flux, N = number of turns\r\n```\r\n\r\n**Magnetic Flux:** Φ = BA cos θ\r\n- B = magnetic field, A = area, θ = angle between B and area normal\r\n\r\n### 3.2 Lenz\'s Law\r\n\"The direction of induced current is such that it opposes the change that produced it.\"\r\n\r\n### 3.3 Fleming\'s Right Hand Rule\r\nUsed to find direction of induced current:\r\n- **Thumb:** Direction of motion of conductor\r\n- **First finger:** Direction of magnetic field  \r\n- **Middle finger:** Direction of induced current\r\n\r\n### 3.4 Methods to Increase Induced EMF\r\n1. Increase the rate of change of magnetic flux\r\n2. Increase the number of turns in the coil\r\n3. Use stronger magnets\r\n4. Move conductor faster through magnetic field\r\n\r\n---\r\n\r\n## ⚙️ 4. PRACTICAL APPLICATIONS\r\n\r\n### 4.1 Electric Motor\r\n**Principle:** Force on current-carrying conductor in magnetic field (Fleming\'s Left Hand Rule)\r\n\r\n**Function:** Converts electrical energy into mechanical energy\r\n\r\n**Construction:**\r\n- Armature (rotating coil)\r\n- Field magnets\r\n- Commutator\r\n- Carbon brushes\r\n\r\n**Applications:** Fans, washing machines, mixers, electric vehicles\r\n\r\n### 4.2 Electric Generator (Dynamo)\r\n**Principle:** Electromagnetic induction (Fleming\'s Right Hand Rule)\r\n\r\n**Function:** Converts mechanical energy into electrical energy\r\n\r\n**EMF Equation:**\r\n```\r\nE = (PΦNz)/(60A)\r\nWhere: P = number of poles, Φ = flux per pole\r\n       N = speed (rpm), z = total conductors, A = parallel paths\r\n```\r\n\r\n**Types:**\r\n- **DC Generator:** Produces direct current\r\n- **AC Generator:** Produces alternating current\r\n\r\n### 4.3 Transformer\r\n**Principle:** Mutual induction between two coils\r\n\r\n**Function:** Changes AC voltage level (step-up or step-down)\r\n\r\n**Transformer Equation:**\r\n```\r\nVp/Vs = Np/Ns = Is/Ip\r\nWhere: p = primary, s = secondary\r\n       V = voltage, N = turns, I = current\r\n```\r\n\r\n**Types:**\r\n- **Step-up Transformer:** Ns > Np (increases voltage)\r\n- **Step-down Transformer:** Ns < Np (decreases voltage)\r\n\r\n**Applications:**\r\n- Power transmission\r\n- Mobile chargers\r\n- Welding transformers\r\n- Distribution systems\r\n\r\n### 4.4 Electric Bell\r\n**Working:**\r\n1. When switch is pressed, current flows through electromagnet\r\n2. Electromagnet attracts iron armature\r\n3. Hammer strikes the gong producing sound\r\n4. Circuit breaks, electromagnet loses magnetism\r\n5. Spring pulls armature back, completing circuit again\r\n6. Process repeats rapidly creating continuous ringing\r\n\r\n---\r\n\r\n## 🔌 5. HOUSEHOLD ELECTRICITY\r\n\r\n### 5.1 Electric Wiring\r\n**Three-wire System:**\r\n- **Live Wire (Red/Brown):** Carries current to appliance\r\n- **Neutral Wire (Black/Blue):** Completes the circuit\r\n- **Earth Wire (Green):** Safety wire for metal bodies\r\n\r\n### 5.2 Safety Devices\r\n\r\n#### Fuse\r\n- Thin wire that melts when excess current flows\r\n- Connected in series with live wire\r\n- **Rating:** Should be slightly higher than normal current\r\n\r\n#### Circuit Breaker\r\n- Electromagnetic switch that opens circuit during overload\r\n- Can be reset after fault is cleared\r\n- More reliable than fuse\r\n\r\n#### Earth Wire\r\n- Connects metal body of appliances to ground\r\n- Provides path for leakage current\r\n- Prevents electric shock\r\n\r\n### 5.3 Electric Power and Energy\r\n\r\n**Power:** P = VI = I²R = V²/R (Watts)\r\n\r\n**Energy:** E = Pt (Joules)\r\n\r\n**Commercial Unit:** kWh (kilowatt-hour)\r\n- 1 kWh = 3.6 × 10⁶ J\r\n- Used for electricity billing\r\n\r\n---\r\n\r\n## 📊 6. IMPORTANT FORMULAS SUMMARY\r\n\r\n### Current and Resistance\r\n- Current: I = Q/t\r\n- Ohm\'s Law: V = IR\r\n- Power: P = VI = I²R = V²/R\r\n- Energy: E = Pt\r\n\r\n### Magnetic Field\r\n- Straight conductor: B = μ₀I/(2πr)\r\n- Circular coil: B = μ₀I/(2r)\r\n- Solenoid: B = μ₀nI\r\n- Force on conductor: F = BIL sin θ\r\n\r\n### Electromagnetic Induction\r\n- Faraday\'s Law: ε = -N(dΦ/dt)\r\n- Magnetic flux: Φ = BA cos θ\r\n- Generator EMF: E = (PΦNz)/(60A)\r\n- Transformer: Vp/Vs = Np/Ns\r\n\r\n### Constants\r\n- μ₀ = 4π × 10⁻⁷ T⋅m/A\r\n- 1 Tesla = 10⁴ Gauss\r\n- 1 kWh = 3.6 × 10⁶ J\r\n\r\n---\r\n\r\n## 🎯 7. EXAM IMPORTANT TOPICS\r\n\r\n### Very Important (Must Know)\r\n1. Faraday\'s laws of electromagnetic induction\r\n2. Fleming\'s left and right hand rules\r\n3. Working principle of motor and generator\r\n4. Transformer principle and equation\r\n5. AC vs DC comparison\r\n6. Magnetic field due to current-carrying conductors\r\n\r\n### Important\r\n1. Electric bell working\r\n2. Safety devices in household wiring\r\n3. kWh and its relation to joule\r\n4. Lenz\'s law\r\n5. Methods to increase induced EMF\r\n6. Types of transformers\r\n\r\n### Moderate\r\n1. Oersted\'s experiment\r\n2. Properties of magnetic field lines\r\n3. Electric power calculations\r\n4. Factors affecting electromagnet strength\r\n\r\n---\r\n\r\n## 💡 8. NUMERICAL PROBLEMS PRACTICE\r\n\r\n### Type 1: Current and Power\r\n**Q1:** A device draws 5A current for 2 hours. Calculate the charge flow.\r\n**Solution:** Q = It = 5 × 2 × 3600 = 36,000 C\r\n\r\n### Type 2: Magnetic Field\r\n**Q2:** Calculate magnetic field at 10 cm from a wire carrying 2A current.\r\n**Solution:** B = μ₀I/(2πr) = (4π×10⁻⁷×2)/(2π×0.1) = 4×10⁻⁶ T\r\n\r\n### Type 3: Transformer\r\n**Q3:** A transformer has 1000 primary turns and 100 secondary turns. If primary voltage is 220V, find secondary voltage.\r\n**Solution:** Vs = Vp × Ns/Np = 220 × 100/1000 = 22V\r\n\r\n---\r\n\r\n## 🔬 9. PRACTICAL EXPERIMENTS\r\n\r\n### Experiment 1: Oersted\'s Experiment\r\n**Aim:** To show magnetic effect of electric current\r\n**Procedure:**\r\n1. Place a compass needle near a current-carrying wire\r\n2. Switch on current and observe needle deflection\r\n3. Reverse current direction and observe\r\n\r\n### Experiment 2: Electromagnetic Induction\r\n**Aim:** To demonstrate Faraday\'s law\r\n**Procedure:**\r\n1. Connect a coil to galvanometer\r\n2. Move a magnet towards/away from coil\r\n3. Observe galvanometer deflection\r\n\r\n---\r\n\r\n## 📝 10. EXAM PREPARATION TIPS\r\n\r\n### For Theory Questions\r\n1. **Definitions:** Learn exact definitions with units\r\n2. **Laws:** State laws with mathematical expressions\r\n3. **Principles:** Understand working principles of devices\r\n4. **Diagrams:** Practice neat labeled diagrams\r\n\r\n### For Numerical Problems\r\n1. **Formulas:** Memorize all important formulas\r\n2. **Units:** Always check unit consistency\r\n3. **Steps:** Show all calculation steps clearly\r\n4. **Practice:** Solve various types of problems\r\n\r\n### Common Mistakes to Avoid\r\n1. Confusing Fleming\'s left and right hand rules\r\n2. Wrong transformer equation application\r\n3. Mixing up AC and DC properties\r\n4. Incorrect magnetic field direction\r\n\r\n---\r\n\r\n## 🏆 11. PREVIOUS YEAR SEE QUESTIONS PATTERN\r\n\r\n### Theory Questions (2-3 marks each)\r\n- Define electromagnetic induction\r\n- State Faraday\'s laws\r\n- Explain working of electric motor\r\n- Compare AC and DC\r\n- Describe safety measures in household wiring\r\n\r\n### Numerical Questions (3-4 marks each)\r\n- Transformer calculations\r\n- Magnetic field calculations\r\n- Power and energy problems\r\n- Current and charge calculations\r\n\r\n### Long Questions (5-6 marks)\r\n- Working principle of generator with diagram\r\n- Complete explanation of transformer\r\n- Electric bell mechanism with diagram\r\n\r\n---\r\n\r\n## 📖 12. ADDITIONAL STUDY RESOURCES\r\n\r\n### Reference Books\r\n1. NEB Textbook (Class 10 Science)\r\n2. Khullakitab Notes\r\n3. Readersnepal Guide\r\n4. Local guide books\r\n\r\n### Online Resources\r\n1. Khan Academy Physics\r\n2. YouTube educational channels\r\n3. PhET simulations\r\n4. Educational websites\r\n\r\n---\r\n\r\n## ✅ 13. CHAPTER CHECKLIST\r\n\r\n**Before SEE Exam, ensure you can:**\r\n- [ ] Explain all three effects of electric current\r\n- [ ] Apply Fleming\'s rules correctly\r\n- [ ] Solve transformer numerical problems\r\n- [ ] Draw and explain motor/generator diagrams  \r\n- [ ] Calculate magnetic fields using formulas\r\n- [ ] Describe household electrical safety\r\n- [ ] Compare different types of current\r\n- [ ] Explain electromagnetic induction completely\r\n\r\n---\r\n\r\n## 🎊 CONCLUSION\r\n\r\nElectricity and Magnetism is a scoring chapter if concepts are clear. Focus on understanding principles rather than memorizing. Practice numerical problems regularly and draw neat diagrams. This chapter forms the foundation for advanced physics topics in higher classes.\r\n\r\n**Remember:** Physics is not about memorizing formulas but understanding the beauty of nature\'s laws!\r\n\r\n---\r\n\r\n*This note is prepared according to NEB curriculum 2080 for SEE examination. Best wishes for your preparation!*\r\n\r\n**📞 Need Help?** Practice more problems and refer to your textbook for additional examples.\r\n\r\n---', 1, '2025-07-25 01:11:38', '2025-09-16 03:05:11'),
(81, 11403, '# Energy – Topper Level Notes (Physics, Grade 10 NEB)\r\n\r\n## 1. What is Energy?\r\n- **Definition:** Energy is the capacity of a body to do work.\r\n- **SI Unit:** Joule (J)\r\n\r\n---\r\n\r\n## 2. Types of Energy\r\n\r\n**A. Kinetic Energy (KE)**\r\n- Energy due to motion.\r\n- **Formula:** KE = ½ mv²  \r\n  (m = mass in kg, v = velocity in m/s)\r\n\r\n**B. Potential Energy (PE)**\r\n- Energy due to position or state.\r\n- **Gravitational PE:** PE = mgh  \r\n  (g = 9.8 m/s², h = height in m)\r\n- **Elastic PE:** PE = ½ kx²  \r\n  (k = spring constant, x = extension/compression)\r\n\r\n**C. Other Important Types**\r\n- **Chemical, Electrical, Thermal, Nuclear, Light, and Sound Energy**\r\n\r\n---\r\n\r\n## 3. Law of Conservation of Energy \r\n- **Statement:** Energy can neither be created nor destroyed, only changed from one form to another.\r\n- **Mathematical Form:**  \r\n  Initial Total Energy = Final Total Energy  \r\n  KE₁ + PE₁ = KE₂ + PE₂\r\n\r\n---\r\n\r\n## 4. Sources of Energy\r\n**A. Renewable:** Solar, Wind, Hydro, Biomass, Geothermal  \r\n**B. Non-renewable:** Coal, Oil, Natural Gas, Nuclear\r\n\r\n---\r\n\r\n## 5. Major Energy Transformations\r\n\r\n| Device/Process        | Original Form   | Final Form        |\r\n|----------------------|-----------------|-------------------|\r\n| Torch                | Chemical        | Light             |\r\n| Hydroelectric Plant  | Potential       | Electrical        |\r\n| Car Engine           | Chemical        | Kinetic/Heat      |\r\n| Electric Bulb        | Electrical      | Light/Heat        |\r\n\r\n---\r\n\r\n## 6. Work-Energy Principle  \r\n- **Work-Energy Theorem:**  \r\n  The net work done on an object equals the change in its kinetic energy.  \r\n  W = KE₂ – KE₁\r\n\r\n---\r\n\r\n## 7. Efficiency\r\n- **Formula:** Efficiency (%) = (Useful output energy / Total input energy) x 100\r\n\r\n---\r\n\r\n## 8. Energy Crisis & Conservation\r\n\r\n- **Crisis:** Overuse of non-renewable resources → shortages & environmental damage.\r\n- **Conservation:** \r\n  - Use energy-saving devices.\r\n  - Switch to renewable sources.\r\n  - Practice efficient consumption.\r\n\r\n---\r\n\r\n## 9. Common Exam Questions\r\n\r\n1. Define energy and its SI unit.\r\n2. Explain the law of conservation of energy with an example.\r\n3. List differences between renewable and non-renewable energy.\r\n4. A 2kg mass is lifted to a height of 5m. Calculate PE. (Ans: 98J)\r\n5. What is the efficiency if a machine gives 600J of output from 1000J input? (Ans: 60%)\r\n\r\n---\r\n\r\n## 10. Important Formulas Summary Table\r\n\r\n| Formula            | Meaning                |\r\n|--------------------|------------------------|\r\n| KE = ½ mv²         | Kinetic Energy         |\r\n| PE = mgh           | Potential Energy       |\r\n| W = Fd             | Work Done              |\r\n| P = W/t            | Power                  |\r\n| Efficiency = (Output/Input) x 100 | Efficiency |\r\n\r\n---\r\n\r\n## 11. Easy Memory Aids\r\n\r\n- **KE:** “Moving Mass, Velocity Squared!”\r\n- **PE:** “Mass x Gravity x Height!”\r\n- **Law of Conservation:** “Energy isn\'t made or lost, only swapped!”\r\n\r\n---\r\n', 1, '2025-07-25 01:11:38', '2025-09-16 03:05:11');
INSERT INTO `course_notes_content` (`id`, `topic_id`, `content`, `markdown_format`, `created_at`, `updated_at`) VALUES
(82, 11401, '# Force - Grade 10 (SEE) Physics\r\n## Complete Chapter Notes with All Exercises - NEB Curriculum 2080\r\n\r\n---\r\n\r\n## 🎯 Chapter Overview\r\n**Chapter 1: Force** is the foundation chapter of Grade 10 Physics for SEE examination. This chapter covers fundamental concepts of gravitational force, Newton\'s laws, weight, mass, and their applications in daily life.\r\n\r\n**Weightage:** 12-15 marks in SEE examination\r\n**Time Required:** 20-25 periods\r\n\r\n---\r\n\r\n## 📚 Learning Objectives\r\nAfter studying this chapter, students will be able to:\r\n- Define force and understand its types\r\n- Explain Newton\'s Universal Law of Gravitation\r\n- Distinguish between mass and weight\r\n- Calculate gravitational force between objects\r\n- Understand concepts of free fall and weightlessness\r\n\r\n---\r\n\r\n## ⚡ 1. FORCE\r\n\r\n### 1.1 Definition\r\nForce can be defined as a push or pull that tries to change the state of a body from motion to rest and rest to motion in a straight line.\r\n\r\n**SI Unit:** Newton (N)\r\n**CGS Unit:** dyne\r\n**Conversion:** 1 N = 10⁵ dynes\r\n\r\n### 1.2 Types of Force\r\n1. **Pulling Force (Attraction Force)**\r\n   - Example: Magnet attracting iron\r\n2. **Pushing Force (Repulsion Force)**\r\n   - Example: Two like poles of magnets\r\n\r\n---\r\n\r\n## 🌍 2. GRAVITATIONAL FORCE\r\n\r\n### 2.1 Definition\r\nThe force of attraction between any two bodies of the universe due to their masses is called gravitational force.\r\n\r\n### 2.2 Newton\'s Universal Law of Gravitation\r\n\r\n**Statement:** \"The force of gravitation between any two bodies in the universe is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centres.\"\r\n\r\n**Mathematical Expression:**\r\n```\r\nF = G(m₁m₂)/d²\r\n\r\nWhere:\r\nF = Gravitational force (N)\r\nG = Universal gravitational constant = 6.67 × 10⁻¹¹ Nm²/kg²\r\nm₁, m₂ = Masses of two bodies (kg)\r\nd = Distance between their centers (m)\r\n```\r\n\r\n### 2.3 Universal Gravitational Constant (G)\r\n\r\n**Definition:** G is defined as the gravitational force produced between two bodies of unit mass each when they are kept at a unit distance from their centre.\r\n\r\n**Value:** G = 6.67 × 10⁻¹¹ Nm²/kg²\r\n**SI Unit:** Nm²/kg²\r\n\r\n**Significance:** If m₁ = 1 kg, m₂ = 1 kg, d = 1 m, then F = G\r\n\r\n---\r\n\r\n## 🔽 3. GRAVITY AND ACCELERATION DUE TO GRAVITY\r\n\r\n### 3.1 Gravity\r\nThe force of attraction of the earth on a body is called gravity.\r\n\r\n### 3.2 Acceleration due to Gravity (g)\r\n\r\n**Definition:** The rate of change of velocity due to gravity is called acceleration due to gravity.\r\n\r\n**Formula Derivation:**\r\n```\r\nFor a body of mass \'m\' on Earth\'s surface:\r\nF = GMm/R² (from Newton\'s law)\r\nF = mg (from Newton\'s second law)\r\n\r\nTherefore: mg = GMm/R²\r\n∴ g = GM/R²\r\n\r\nWhere:\r\ng = acceleration due to gravity (m/s²)\r\nG = gravitational constant\r\nM = mass of Earth\r\nR = radius of Earth\r\n```\r\n\r\n**Standard Value:** g = 9.8 m/s² (on Earth)\r\n\r\n### 3.3 Variation of \'g\'\r\n- **g ∝ 1/R²** (inversely proportional to square of radius)\r\n- g is greater at poles than at equator\r\n- g decreases with altitude\r\n- g varies from planet to planet\r\n\r\n---\r\n\r\n## ⚖️ 4. MASS AND WEIGHT\r\n\r\n### 4.1 Mass\r\n- Amount of matter contained in a body\r\n- Remains constant everywhere in universe\r\n- Scalar quantity\r\n- SI Unit: kilogram (kg)\r\n\r\n### 4.2 Weight\r\n- Force with which a body is attracted towards center of Earth\r\n- Changes from place to place\r\n- Vector quantity\r\n- SI Unit: Newton (N)\r\n\r\n**Relationship:** Weight = mg\r\n\r\n### 4.3 Comparison Table\r\n\r\n| Mass | Weight |\r\n|------|--------|\r\n| Amount of matter in body | Force of attraction by Earth |\r\n| Constant everywhere | Varies with location |\r\n| Scalar quantity | Vector quantity |\r\n| Unit: kg | Unit: N |\r\n| Measured by beam balance | Measured by spring balance |\r\n\r\n---\r\n\r\n## 🍎 5. FREE FALL AND WEIGHTLESSNESS\r\n\r\n### 5.1 Free Fall\r\n**Definition:** When a body falls freely towards the center of Earth under the influence of gravitational pull, the motion is called free fall.\r\n\r\n**Characteristics:**\r\n- Initial velocity (u) = 0\r\n- Acceleration = g = 9.8 m/s²\r\n- Air resistance neglected\r\n\r\n**Equations of Motion for Free Fall:**\r\n```\r\nv = u + gt = gt (since u = 0)\r\nh = ut + ½gt² = ½gt²\r\nv² = u² + 2gh = 2gh\r\n```\r\n\r\n### 5.2 Weightlessness\r\n**Definition:** Weightlessness is the state of a body in which it feels that it is not influenced by any force.\r\n\r\n**Examples:**\r\n- Person in a falling lift\r\n- Astronauts in satellites\r\n- Objects in free fall\r\n\r\n**Condition:** When acceleration of body equals acceleration due to gravity\r\n\r\n---\r\n\r\n## 📊 6. COMPLETE EXERCISE SOLUTIONS\r\n\r\n### **2. Answer the following questions:**\r\n\r\n**a. What is gravitation? What are the factors that affect gravitation? Write the SI unit of gravitation.**\r\n\r\n**Answer:** The mutual force of attraction between two bodies is called gravitation.\r\n\r\n**Factors affecting gravitation:**\r\n- Mass of the bodies\r\n- Distance between their centers\r\n\r\n**SI unit:** Newton (N)\r\n\r\n**b. State Newton\'s Universal Law of gravitation.**\r\n\r\n**Answer:** Universal law of gravitation states that \"everybody in this universe attracts another body with a force, which is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centres.\"\r\n\r\n**c. What will happen to the gravitational force between two bodies if the distance between them is halved keeping their masses constant?**\r\n\r\n**Answer:** \r\nGiven: F = Gm₁m₂/d² ... (i)\r\n\r\nIf distance is halved: d₂ = d/2\r\n\r\nNew force: F₂ = Gm₁m₂/(d/2)² = Gm₁m₂/(d²/4) = 4Gm₁m₂/d² ... (ii)\r\n\r\nFrom (i) and (ii): F₂ = 4F\r\n\r\n**Therefore, the gravitational force becomes 4 times greater.**\r\n\r\n**d. What will be the gravitational force between two heavenly bodies if the masses of both are tripled keeping the distance constant?**\r\n\r\n**Answer:**\r\nGiven: F = Gm₁m₂/d² ... (i)\r\n\r\nIf masses are tripled: m₁\' = 3m₁, m₂\' = 3m₂\r\n\r\nNew force: F₂ = G(3m₁)(3m₂)/d² = 9Gm₁m₂/d² ... (ii)\r\n\r\nFrom (i) and (ii): F₂ = 9F\r\n\r\n**Therefore, the gravitational force becomes 9 times greater.**\r\n\r\n**e. What will be the gravitational force between two bodies if the masses of each is doubled and the distance between them is halved?**\r\n\r\n**Answer:**\r\nGiven: F = Gm₁m₂/d² ... (i)\r\n\r\nIf masses are doubled and distance halved:\r\n- m₁\' = 2m₁, m₂\' = 2m₂\r\n- d\' = d/2\r\n\r\nNew force: F₂ = G(2m₁)(2m₂)/(d/2)² = 4Gm₁m₂/(d²/4) = 16Gm₁m₂/d² ... (ii)\r\n\r\nFrom (i) and (ii): F₂ = 16F\r\n\r\n**Therefore, the gravitational force becomes 16 times greater.**\r\n\r\n**f. Define G. Also write its value and SI unit.**\r\n\r\n**Answer:** G is defined as the gravitational force produced between two bodies of unit mass each when they are kept at a unit distance from their center.\r\n\r\n**Value:** 6.67 × 10⁻¹¹ Nm²/kg²\r\n**SI Unit:** Nm²/kg²\r\n\r\n**g. In the formula g = GM/R², what do G, M and R stand for? Prove that g ∝ 1/R².**\r\n\r\n**Answer:** \r\n- G = Gravitational constant\r\n- M = Mass of the Earth\r\n- R = Radius of the Earth\r\n\r\n**Proof:**\r\nLet \'m\' be the mass of an object on Earth\'s surface.\r\n\r\nFrom Newton\'s law: F = GMm/R² ... (i)\r\nFrom Newton\'s second law: F = mg ... (ii)\r\n\r\nEquating (i) and (ii): mg = GMm/R²\r\n\r\nTherefore: g = GM/R²\r\n\r\nSince G and M are constants: g ∝ 1/R²\r\n\r\n**h. What will be the effect on the acceleration due to gravity of the earth if it is compressed to the size of the moon?**\r\n\r\n**Answer:** If Earth is compressed to the size of moon, the acceleration due to gravity will increase because g ∝ 1/R². As radius decreases, g increases.\r\n\r\n**i. The acceleration due to gravity of Jupiter is 25 m/s². What does it mean?**\r\n\r\n**Answer:** It means that if any object is dropped near Jupiter\'s surface, it will accelerate downward at the rate of 25 m/s² due to Jupiter\'s gravity.\r\n\r\n**j. A coin and a feather are dropped in vacuum. Which one will reach the ground first? Why?**\r\n\r\n**Answer:** Both will reach the ground at the same time because in vacuum there is no air resistance, and acceleration due to gravity is same for all objects regardless of their mass.\r\n\r\n**k. Where does a body have more weight - at the pole or at the equator of the earth? Explain with reason.**\r\n\r\n**Answer:** A body has more weight at poles than at equator because polar radius is less than equatorial radius. Since g ∝ 1/R², gravity is stronger at poles, making weight greater.\r\n\r\n**l. When an apple falls towards the earth, the earth moves up to meet the apple. Is this true? If yes, why is the earth\'s motion not noticeable?**\r\n\r\n**Answer:** Yes, it is true according to Newton\'s third law. However, Earth\'s motion is not noticeable because Earth\'s mass is enormously larger than the apple\'s mass, so its acceleration is negligibly small.\r\n\r\n**m. An astronaut is said to be weightless when he travels in a satellite. Does it mean that the earth does not attract him?**\r\n\r\n**Answer:** No, Earth still attracts the astronaut. Weightlessness occurs because both the astronaut and satellite are in free fall together, creating the sensation of zero weight.\r\n\r\n**n. What is the importance of gravitational force? Write any two points.**\r\n\r\n**Answer:**\r\n1. We are able to perform our daily activities due to gravitational force\r\n2. The existence of atmosphere around Earth is possible due to gravitational force\r\n\r\n**o. What is free fall? What happens to the weight of a body when it is falling freely under the action of gravity?**\r\n\r\n**Answer:** When a body falls freely towards Earth\'s center under gravitational influence, the motion is called free fall. During free fall, the apparent weight becomes zero because the body accelerates at g.\r\n\r\n**p. What is the effect of gravity on a falling object? Write the conclusion obtained from the coin and feather experiment.**\r\n\r\n**Answer:** Gravity causes falling objects to accelerate toward Earth. The coin and feather experiment proves that in vacuum, all objects fall at the same rate independent of their masses.\r\n\r\n**q. Write the differences between the fall of a parachute on Earth and its fall on the moon. On what condition does a body have free fall?**\r\n\r\n**Answer:** On Earth, parachute falls slowly due to air resistance and stronger gravity. On moon, it falls faster (no air resistance) but with weaker gravity. \r\n\r\n**Condition for free fall:** When acceleration of body equals acceleration due to gravity.\r\n\r\n**r. Write any two examples of weightlessness.**\r\n\r\n**Answer:**\r\n1. Person in a falling lift\r\n2. Astronauts in satellites\r\n\r\n**s. Define:**\r\n\r\n**i. Acceleration due to gravity:** The acceleration produced on a body due to Earth\'s gravitational force.\r\n\r\n**ii. Weightlessness:** State of a body when it feels no gravitational force acting on it.\r\n\r\n**iii. Free fall:** Motion of a body falling freely under gravity with no external resistance.\r\n\r\n**iv. Null point:** Point between two celestial bodies where net gravitational force is zero.\r\n\r\n---\r\n\r\n### **3. Distinguish between:**\r\n\r\n**a. Gravity and Gravitation**\r\n\r\n| Gravity | Gravitation |\r\n|---------|-------------|\r\n| Force of attraction of Earth on a body | Mutual force of attraction between any two bodies |\r\n| Strong force | Weak force |\r\n| Example: Earth pulls 1kg object with 9.8N | Example: Attraction between books, planets |\r\n\r\n**b. Gravity and Acceleration due to gravity**\r\n\r\n| Gravity | Acceleration due to gravity |\r\n|---------|----------------------------|\r\n| Force of attraction of Earth | Acceleration produced due to gravity |\r\n| Cause of acceleration | Effect of gravity |\r\n| SI unit: Newton | SI unit: m/s² |\r\n\r\n**c. Mass and Weight**\r\n\r\n| Mass | Weight |\r\n|------|--------|\r\n| Amount of matter in body | Force of attraction by Earth |\r\n| Same everywhere | Varies with location |\r\n| Scalar quantity | Vector quantity |\r\n\r\n**d. g and G**\r\n\r\n| g | G |\r\n|---|---|\r\n| Acceleration due to gravity | Universal gravitational constant |\r\n| Unit: m/s² | Unit: Nm²/kg² |\r\n| Vector quantity | Scalar quantity |\r\n\r\n**e. Free fall and Weightlessness**\r\n\r\n| Free fall | Weightlessness |\r\n|-----------|----------------|\r\n| Body falling under gravity only | State of feeling no gravitational force |\r\n| Example: Fruit falling from tree | Example: Person in falling lift |\r\n\r\n**f. Gravitational force and Acceleration due to gravity**\r\n\r\n| Gravitational Force | Acceleration due to gravity |\r\n|--------------------|----------------------------|\r\n| Force of attraction between masses | Acceleration produced by gravity |\r\n| SI unit: Newton | SI unit: m/s² |\r\n\r\n**g. Weightlessness in space and weightlessness on Earth**\r\n\r\n| Weightlessness in Space | Weightlessness on Earth |\r\n|-------------------------|-------------------------|\r\n| Apparent weight zero in space | Apparent weight zero on Earth |\r\n| Occurs at null point | Occurs during free fall |\r\n\r\n---\r\n\r\n### **4. Give reason:**\r\n\r\n**a. Newton\'s law of gravitation is called a universal law.**\r\n\r\n**Answer:** Because this law applies to all bodies in the universe, from microscopic particles to massive celestial bodies.\r\n\r\n**b. The weight of a body decreases with increase in distance from the earth\'s surface.**\r\n\r\n**Answer:** Because g ∝ 1/R². As distance from Earth increases, value of g decreases, hence weight decreases.\r\n\r\n**c. The weight of a stone is less at the top of a mountain than at its bottom.**\r\n\r\n**Answer:** Because g is greater at bottom (closer to sea level) than at top due to less distance from Earth\'s center.\r\n\r\n**d. The weight of a body is less on the moon than its weight on the earth.**\r\n\r\n**Answer:** Because moon has weaker gravitational force than Earth due to smaller mass and radius.\r\n\r\n**e. The moon has no atmosphere.**\r\n\r\n**Answer:** Because moon\'s gravitational force is too weak to hold gas molecules in its atmosphere.\r\n\r\n**f. The value of g is greater at the poles than at the equator.**\r\n\r\n**Answer:** Because polar radius is smaller than equatorial radius, and g ∝ 1/R².\r\n\r\n**g. There is more role of the moon than the sun to cause tides in oceans.**\r\n\r\n**Answer:** Although sun is more massive, moon is much closer to Earth, making its gravitational effect stronger for causing tides.\r\n\r\n**h. Tides occur in oceans but not in lakes.**\r\n\r\n**Answer:** Because ocean water mass is much larger than lake water, making gravitational effects more noticeable.\r\n\r\n**i. It is difficult to lift a large stone on the surface of the earth but it is easy to lift a small one.**\r\n\r\n**Answer:** Because large stone has more mass, so Earth attracts it with greater gravitational force.\r\n\r\n**j. Mass of Jupiter is 319 times more than Earth but its acceleration due to gravity is only 2.5 times more.**\r\n\r\n**Answer:** Because Jupiter\'s radius is about 11 times larger than Earth\'s, and g ∝ 1/R².\r\n\r\n**k. The weight of a body will be zero during free fall.**\r\n\r\n**Answer:** Because during free fall, the body\'s acceleration equals g, making apparent weight zero.\r\n\r\n**l. A paratrooper does not get injured while jumping from a flying aeroplane.**\r\n\r\n**Answer:** Because parachute increases air resistance, reducing the falling acceleration and impact force.\r\n\r\n**m. When a coin and feather are dropped from a building, the coin reaches ground earlier.**\r\n\r\n**Answer:** Because coin has greater mass and experiences less air resistance compared to feather.\r\n\r\n---\r\n\r\n### **5. Diagrammatic Questions:**\r\n\r\n**1. Earth\'s orbit around sun - gravitational force variation**\r\n\r\n**Answer:** The gravitational force increases as Earth moves from point A to point B because distance to sun is less at B than A, and F ∝ 1/d².\r\n\r\n**2. Feather and coin experiment**\r\n\r\n**a. Name of experiment:** \"Feather and coin\" experiment\r\n\r\n**b. Conclusion:** In vacuum, all objects fall with same acceleration regardless of mass.\r\n\r\n**c. Effect with air:** Coin falls first because it has less air resistance than feather.\r\n\r\n**3. Gravitational force calculation**\r\n\r\n**Given:**\r\n- m₁ = 800 kg\r\n- m₂ = 400 kg  \r\n- d = 8 m\r\n- G = 6.67 × 10⁻¹¹ Nm²/kg²\r\n\r\n**Solution:**\r\nF = Gm₁m₂/d²\r\nF = (6.67 × 10⁻¹¹ × 800 × 400)/8²\r\nF = (6.67 × 10⁻¹¹ × 320000)/64\r\nF = 3.335 × 10⁻⁷ N\r\n\r\n---\r\n\r\n## 🔢 6. NUMERICAL PROBLEMS\r\n\r\n### **Problem Type 1: Gravitational Force Calculation**\r\n\r\n**Q1:** Calculate the gravitational force between two objects of masses 50 kg and 80 kg separated by 10 m.\r\n\r\n**Given:**\r\n- m₁ = 50 kg\r\n- m₂ = 80 kg\r\n- d = 10 m\r\n- G = 6.67 × 10⁻¹¹ Nm²/kg²\r\n\r\n**Solution:**\r\nF = Gm₁m₂/d²\r\nF = (6.67 × 10⁻¹¹ × 50 × 80)/10²\r\nF = (6.67 × 10⁻¹¹ × 4000)/100\r\nF = 2.668 × 10⁻⁹ N\r\n\r\n### **Problem Type 2: Weight Calculation**\r\n\r\n**Q2:** Calculate the weight of a 75 kg person on Earth\'s surface.\r\n\r\n**Given:**\r\n- m = 75 kg\r\n- g = 9.8 m/s²\r\n\r\n**Solution:**\r\nWeight = mg\r\nWeight = 75 × 9.8 = 735 N\r\n\r\n### **Problem Type 3: Free Fall Problems**\r\n\r\n**Q3:** A ball is dropped from height of 45 m. Calculate time taken to reach ground.\r\n\r\n**Given:**\r\n- h = 45 m\r\n- u = 0 (dropped)\r\n- g = 9.8 m/s²\r\n\r\n**Solution:**\r\nh = ut + ½gt²\r\n45 = 0 + ½ × 9.8 × t²\r\n45 = 4.9t²\r\nt² = 45/4.9 = 9.18\r\nt = 3.03 s\r\n\r\n### **Problem Type 4: Variation Problems**\r\n\r\n**Q4:** If gravitational force between two objects is 100 N, what will be the force if distance is doubled?\r\n\r\n**Given:**\r\n- Initial force F₁ = 100 N\r\n- New distance d₂ = 2d₁\r\n\r\n**Solution:**\r\nF₁ = Gm₁m₂/d₁²\r\nF₂ = Gm₁m₂/(2d₁)² = Gm₁m₂/4d₁²\r\n\r\nF₂ = F₁/4 = 100/4 = 25 N\r\n\r\n### **Problem Type 5: Weight on Different Planets**\r\n\r\n**Q5:** A person weighs 600 N on Earth. What will be his weight on Jupiter? (g_Jupiter = 25 m/s²)\r\n\r\n**Given:**\r\n- Weight on Earth = 600 N\r\n- g_Earth = 9.8 m/s²\r\n- g_Jupiter = 25 m/s²\r\n\r\n**Solution:**\r\nMass = Weight_Earth/g_Earth = 600/9.8 = 61.22 kg\r\n\r\nWeight on Jupiter = mass × g_Jupiter\r\nWeight on Jupiter = 61.22 × 25 = 1530.5 N\r\n\r\n---\r\n\r\n## 📈 7. IMPORTANT FORMULAS SUMMARY\r\n\r\n### **Force and Gravitation**\r\n- F = Gm₁m₂/d²\r\n- G = 6.67 × 10⁻¹¹ Nm²/kg²\r\n- Weight = mg\r\n- g = GM/R²\r\n\r\n### **Free Fall Equations**\r\n- v = gt (when u = 0)\r\n- h = ½gt²\r\n- v² = 2gh\r\n\r\n### **Relationships**\r\n- F ∝ m₁m₂ (masses)\r\n- F ∝ 1/d² (distance)\r\n- g ∝ 1/R² (radius)\r\n- Weight ∝ g (gravity)\r\n\r\n---\r\n\r\n## 🎯 8. EXAM PREPARATION TIPS\r\n\r\n### **Theory Questions (2-3 marks)**\r\n- Learn exact definitions with units\r\n- Practice distinguishing between concepts\r\n- Memorize Newton\'s laws and statements\r\n- Draw neat labeled diagrams\r\n\r\n### **Give Reason Questions (2-3 marks)**\r\n- Understand cause-effect relationships\r\n- Use formulas to support reasoning\r\n- Connect to daily life examples\r\n- Practice explaining variations\r\n\r\n### **Numerical Problems (3-4 marks)**\r\n- Memorize all important formulas\r\n- Show all calculation steps\r\n- Check unit consistency\r\n- Practice different problem types\r\n\r\n### **Long Questions (5-6 marks)**\r\n- Complete derivations with steps\r\n- Detailed explanations with examples\r\n- Multiple parts of same concept\r\n- Diagrams where required\r\n\r\n---\r\n\r\n## 🏆 9. PREVIOUS YEAR SEE QUESTIONS PATTERN\r\n\r\n### **Common Theory Questions**\r\n- Define gravitation and its factors\r\n- State Newton\'s universal law\r\n- Distinguish between mass and weight\r\n- Explain free fall and weightlessness\r\n- Give reasons for gravitational variations\r\n\r\n### **Common Numerical Types**\r\n- Gravitational force between objects\r\n- Weight calculations on different planets\r\n- Free fall time and velocity problems\r\n- Force variation with distance/mass changes\r\n- Comparison problems\r\n\r\n### **Important Diagrams**\r\n- Earth\'s elliptical orbit showing gravitational variation\r\n- Feather and coin experiment setup\r\n- Free body diagrams showing forces\r\n- Gravitational force between two spheres\r\n\r\n---\r\n\r\n## ✅ 10. CHAPTER CHECKLIST\r\n\r\n**Before SEE Exam, ensure you can:**\r\n- [ ] Define force, gravity, and gravitation clearly\r\n- [ ] State and apply Newton\'s universal law\r\n- [ ] Distinguish between all given concepts\r\n- [ ] Solve all types of numerical problems\r\n- [ ] Explain all \"give reason\" questions\r\n- [ ] Draw required diagrams accurately\r\n- [ ] Understand free fall and weightlessness\r\n- [ ] Calculate weights on different planets\r\n\r\n---\r\n\r\n## 🎊 CONCLUSION\r\n\r\nForce is a fundamental chapter that builds the foundation for understanding motion, energy, and other physics concepts. Master the definitions, formulas, and numerical problem-solving techniques. Practice distinguishing between similar concepts and explaining daily life phenomena using gravitational principles.\r\n\r\n**Key Success Formula:** \r\nConcept Understanding + Formula Practice + Numerical Solving = SEE Success!\r\n\r\n---\r\n\r\n*This complete note covers all exercises from the Force chapter of NEB Science textbook for SEE examination preparation. Practice regularly and refer to your textbook for additional examples.*\r\n\r\n**📞 Need Help?** Review the numerical problems and practice more variations for complete mastery.\r\n\r\n---', 1, '2025-07-25 01:11:38', '2025-09-16 03:05:11'),
(83, 11405, '# Light - Grade 10 (SEE) Physics\r\n## Complete Chapter Notes with All Exercises - NEB Curriculum 2080\r\n\r\n---\r\n\r\n## 🎯 Chapter Overview\r\n**Chapter 5: Light** is one of the most crucial chapters in Grade 10 Physics for SEE examination. This chapter covers fundamental concepts of reflection, refraction, mirrors, lenses, and their practical applications in daily life.\r\n\r\n**Weightage:** 15-18 marks in SEE examination\r\n**Time Required:** 30-35 periods\r\n\r\n---\r\n\r\n## 📚 Learning Objectives\r\nAfter studying this chapter, students will be able to:\r\n- Understand properties and behavior of light\r\n- Explain laws of reflection and refraction\r\n- Analyze image formation in mirrors and lenses\r\n- Apply mirror and lens formulas to solve problems\r\n- Draw accurate ray diagrams for various optical situations\r\n\r\n---\r\n\r\n## 💡 1. INTRODUCTION TO LIGHT\r\n\r\n### 1.1 Definition\r\nLight is a form of energy that enables us to see objects around us. It travels in straight lines and shows both wave and particle nature.\r\n\r\n**Properties of Light:**\r\n- Light travels in straight lines (rectilinear propagation)\r\n- Speed of light in vacuum = 3 × 10⁸ m/s\r\n- Light shows reflection, refraction, and dispersion\r\n- Light carries energy and momentum\r\n\r\n### 1.2 Sources of Light\r\n**Natural Sources:** Sun, stars, fireflies, lightning\r\n**Artificial Sources:** Electric bulb, candle, LED, laser\r\n\r\n---\r\n\r\n## 🪞 2. REFLECTION OF LIGHT\r\n\r\n### 2.1 Definition\r\nThe bouncing back of light when it strikes a surface is called reflection of light.\r\n\r\n### 2.2 Laws of Reflection\r\n1. **First Law:** The incident ray, reflected ray, and normal to the surface at the point of incidence all lie in the same plane.\r\n2. **Second Law:** The angle of incidence is equal to the angle of reflection.\r\n   **∠i = ∠r**\r\n\r\n### 2.3 Types of Reflection\r\n**Regular Reflection:** Occurs on smooth polished surfaces (plane mirror)\r\n**Irregular Reflection:** Occurs on rough surfaces (diffused reflection)\r\n\r\n---\r\n\r\n## 🔄 3. SPHERICAL MIRRORS\r\n\r\n### 3.1 Definition\r\nSpherical mirrors are mirrors whose reflecting surfaces are curved like a sphere.\r\n\r\n### 3.2 Types of Spherical Mirrors\r\n\r\n#### A. Concave Mirror (Converging Mirror)\r\n- Reflecting surface curves inward\r\n- Converges parallel rays to a point\r\n- Real and virtual images both possible\r\n\r\n#### B. Convex Mirror (Diverging Mirror)\r\n- Reflecting surface curves outward  \r\n- Diverges parallel rays\r\n- Always forms virtual, erect, diminished images\r\n\r\n### 3.3 Important Terms\r\n\r\n**Centre of Curvature (C):** Centre of the sphere of which mirror is a part\r\n**Radius of Curvature (R):** Radius of the sphere of which mirror is a part\r\n**Pole (P):** Centre point of the mirror surface\r\n**Principal Axis:** Imaginary line passing through pole and centre of curvature\r\n**Principal Focus (F):** Point on principal axis where parallel rays converge or appear to diverge\r\n**Focal Length (f):** Distance between pole and principal focus\r\n**Aperture:** Effective diameter of the mirror\r\n\r\n**Relationship:** f = R/2\r\n\r\n---\r\n\r\n## 📐 4. RAY DIAGRAMS AND IMAGE FORMATION\r\n\r\n### 4.1 Rules for Drawing Ray Diagrams\r\n\r\n#### For Concave Mirror:\r\n1. **Ray parallel to principal axis** → reflects through focus\r\n2. **Ray through focus** → reflects parallel to principal axis\r\n3. **Ray through centre of curvature** → reflects back along same path\r\n4. **Ray hitting pole** → reflects symmetrically about principal axis\r\n\r\n#### For Convex Mirror:\r\n1. **Ray parallel to principal axis** → appears to come from focus after reflection\r\n2. **Ray toward focus** → reflects parallel to principal axis\r\n3. **Ray toward centre** → reflects back along same path\r\n\r\n### 4.2 Image Formation in Concave Mirror\r\n\r\n| Object Position | Image Position | Image Nature | Image Size |\r\n|-----------------|----------------|--------------|------------|\r\n| At infinity | At F | Real, inverted | Point sized |\r\n| Beyond C | Between F and C | Real, inverted | Diminished |\r\n| At C | At C | Real, inverted | Same size |\r\n| Between C and F | Beyond C | Real, inverted | Enlarged |\r\n| At F | At infinity | Real, inverted | Highly enlarged |\r\n| Between F and P | Behind mirror | Virtual, erect | Enlarged |\r\n\r\n### 4.3 Image Formation in Convex Mirror\r\n- **Always:** Virtual, erect, diminished\r\n- **Position:** Between pole and focus\r\n- **Applications:** Rear-view mirrors, security mirrors\r\n\r\n---\r\n\r\n## 📝 5. MIRROR FORMULA AND MAGNIFICATION\r\n\r\n### 5.1 Mirror Formula\r\n```\r\n1/f = 1/v + 1/u\r\n\r\nWhere:\r\nf = focal length\r\nv = image distance\r\nu = object distance\r\n```\r\n\r\n### 5.2 Sign Convention (New Cartesian)\r\n- All distances measured from pole of mirror\r\n- Distances measured in direction of incident light are positive\r\n- Distances measured opposite to incident light are negative\r\n- Heights measured upward are positive, downward are negative\r\n\r\n**For Concave Mirror:** f = negative\r\n**For Convex Mirror:** f = positive\r\n\r\n### 5.3 Magnification\r\n```\r\nm = -v/u = h\'/h\r\n\r\nWhere:\r\nm = magnification\r\nv = image distance\r\nu = object distance  \r\nh\' = image height\r\nh = object height\r\n```\r\n\r\n**Magnification Types:**\r\n- **m > 1:** Enlarged image\r\n- **m < 1:** Diminished image\r\n- **m = 1:** Same size image\r\n- **m = positive:** Virtual, erect image\r\n- **m = negative:** Real, inverted image\r\n\r\n---\r\n\r\n## 🌈 6. REFRACTION OF LIGHT\r\n\r\n### 6.1 Definition\r\nThe bending of light when it passes from one medium to another is called refraction.\r\n\r\n### 6.2 Laws of Refraction (Snell\'s Laws)\r\n1. **First Law:** Incident ray, refracted ray, and normal lie in same plane\r\n2. **Second Law:** For any two given media, the ratio of sine of angle of incidence to sine of angle of refraction is constant\r\n   ```\r\n   sin i/sin r = μ = constant\r\n   ```\r\n\r\n### 6.3 Refractive Index\r\n```\r\nμ = c/v = sin i/sin r\r\n\r\nWhere:\r\nμ = refractive index\r\nc = speed of light in vacuum\r\nv = speed of light in medium\r\ni = angle of incidence\r\nr = angle of refraction\r\n```\r\n\r\n**Absolute Refractive Index:** Refractive index with respect to vacuum\r\n**Relative Refractive Index:** ₁μ₂ = μ₂/μ₁\r\n\r\n### 6.4 Refraction through Glass Slab\r\n- Light bends toward normal when entering denser medium\r\n- Light bends away from normal when entering rarer medium\r\n- Emergent ray is parallel to incident ray but laterally displaced\r\n\r\n---\r\n\r\n## 🔍 7. LENSES\r\n\r\n### 7.1 Definition\r\nA transparent medium bounded by two spherical surfaces is called a lens.\r\n\r\n### 7.2 Types of Lenses\r\n\r\n#### A. Convex Lens (Converging Lens)\r\n- Thicker at middle, thinner at edges\r\n- Converges parallel rays\r\n- Can form real and virtual images\r\n\r\n#### B. Concave Lens (Diverging Lens)\r\n- Thinner at middle, thicker at edges\r\n- Diverges parallel rays\r\n- Always forms virtual images\r\n\r\n### 7.3 Image Formation by Convex Lens\r\n\r\n| Object Position | Image Position | Image Nature | Image Size |\r\n|-----------------|----------------|--------------|------------|\r\n| At infinity | At F | Real, inverted | Point sized |\r\n| Beyond 2F | Between F and 2F | Real, inverted | Diminished |\r\n| At 2F | At 2F | Real, inverted | Same size |\r\n| Between 2F and F | Beyond 2F | Real, inverted | Enlarged |\r\n| At F | At infinity | Real, inverted | Highly enlarged |\r\n| Between F and O | Same side | Virtual, erect | Enlarged |\r\n\r\n### 7.4 Image Formation by Concave Lens\r\n- **Always:** Virtual, erect, diminished\r\n- **Position:** Between object and lens\r\n\r\n---\r\n\r\n## 📊 8. LENS FORMULA AND POWER\r\n\r\n### 8.1 Lens Formula\r\n```\r\n1/f = 1/v - 1/u\r\n\r\nWhere:\r\nf = focal length\r\nv = image distance\r\nu = object distance\r\n```\r\n\r\n### 8.2 Sign Convention for Lenses\r\n- Object distance (u) is always negative\r\n- For real images: v is positive\r\n- For virtual images: v is negative\r\n- For convex lens: f is positive\r\n- For concave lens: f is negative\r\n\r\n### 8.3 Power of Lens\r\n```\r\nP = 1/f (in meters)\r\n\r\nSI Unit: Dioptre (D)\r\n1 D = 1 m⁻¹\r\n```\r\n\r\n**Power Applications:**\r\n- Convex lens has positive power\r\n- Concave lens has negative power\r\n- Higher power = shorter focal length\r\n\r\n---\r\n\r\n## 📋 9. COMPLETE EXERCISE SOLUTIONS\r\n\r\n### **2. Answer the following questions:**\r\n\r\n**a. What is light? Write any two properties of light.**\r\n\r\n**Answer:** Light is a form of energy that enables us to see objects around us.\r\n\r\n**Properties:**\r\n1. Light travels in straight lines\r\n2. Light shows reflection and refraction\r\n\r\n**b. State the laws of reflection.**\r\n\r\n**Answer:** \r\n1. The incident ray, reflected ray, and normal all lie in the same plane\r\n2. The angle of incidence is equal to the angle of reflection (∠i = ∠r)\r\n\r\n**c. What is the difference between regular and irregular reflection?**\r\n\r\n**Answer:**\r\n- **Regular Reflection:** Occurs on smooth surfaces, all reflected rays are parallel\r\n- **Irregular Reflection:** Occurs on rough surfaces, reflected rays scatter in different directions\r\n\r\n**d. Define the following terms related to spherical mirrors:**\r\n**i. Centre of curvature:** Centre of the sphere of which mirror is a part\r\n**ii. Radius of curvature:** Radius of the sphere of which mirror is a part\r\n**iii. Principal focus:** Point where parallel rays converge or appear to diverge\r\n**iv. Focal length:** Distance between pole and principal focus\r\n\r\n**e. What is the relationship between focal length and radius of curvature?**\r\n\r\n**Answer:** f = R/2 (Focal length is half of radius of curvature)\r\n\r\n**f. Where should an object be placed in front of a concave mirror to get a real image of the same size?**\r\n\r\n**Answer:** At the centre of curvature (C)\r\n\r\n**g. Where should an object be placed to get a virtual and enlarged image in a concave mirror?**\r\n\r\n**Answer:** Between focus (F) and pole (P)\r\n\r\n**h. Write two uses each of concave and convex mirrors.**\r\n\r\n**Answer:**\r\n**Concave mirrors:**\r\n1. Used in headlights of vehicles\r\n2. Used by doctors in examination\r\n\r\n**Convex mirrors:**\r\n1. Used as rear-view mirrors in vehicles\r\n2. Used as security mirrors in shops\r\n\r\n**i. State the laws of refraction.**\r\n\r\n**Answer:**\r\n1. Incident ray, refracted ray, and normal lie in same plane\r\n2. sin i/sin r = constant (Snell\'s law)\r\n\r\n**j. Define refractive index. Write its formula.**\r\n\r\n**Answer:** Refractive index is the ratio of speed of light in vacuum to speed of light in the medium.\r\n**Formula:** μ = c/v = sin i/sin r\r\n\r\n**k. Light travels faster in which medium - air or water? Why?**\r\n\r\n**Answer:** Light travels faster in air because air is rarer medium (lower refractive index) than water.\r\n\r\n**l. What happens to the path of light when it travels from:**\r\n**i. Rarer to denser medium:** Bends toward normal\r\n**ii. Denser to rarer medium:** Bends away from normal\r\n\r\n**m. A ray of light is incident normally on a glass surface. What happens to it?**\r\n\r\n**Answer:** It passes through without deviation because angle of incidence is 0°.\r\n\r\n**n. What is a lens? Mention the types of lenses.**\r\n\r\n**Answer:** A lens is a transparent medium bounded by two spherical surfaces.\r\n**Types:**\r\n1. Convex lens (converging)\r\n2. Concave lens (diverging)\r\n\r\n**o. Where should an object be placed to get a real, inverted and same size image from a convex lens?**\r\n\r\n**Answer:** At 2F (twice the focal length)\r\n\r\n**p. Define power of a lens. Write its SI unit.**\r\n\r\n**Answer:** Power of a lens is the reciprocal of its focal length in meters.\r\n**SI Unit:** Dioptre (D)\r\n**Formula:** P = 1/f\r\n\r\n**q. A convex lens has positive power while concave lens has negative power. Why?**\r\n\r\n**Answer:** Because convex lens has positive focal length (converging) while concave lens has negative focal length (diverging).\r\n\r\n---\r\n\r\n### **3. Distinguish between:**\r\n\r\n**a. Real and Virtual Image**\r\n\r\n| Real Image | Virtual Image |\r\n|------------|---------------|\r\n| Can be obtained on screen | Cannot be obtained on screen |\r\n| Formed by actual intersection of rays | Formed by apparent intersection of rays |\r\n| Always inverted | Can be erect or inverted |\r\n| Example: Image on cinema screen | Example: Image in plane mirror |\r\n\r\n**b. Concave and Convex Mirror**\r\n\r\n| Concave Mirror | Convex Mirror |\r\n|----------------|---------------|\r\n| Reflecting surface curves inward | Reflecting surface curves outward |\r\n| Converges parallel rays | Diverges parallel rays |\r\n| Forms real and virtual images | Forms only virtual images |\r\n| Focal length is negative | Focal length is positive |\r\n\r\n**c. Concave and Convex Lens**\r\n\r\n| Concave Lens | Convex Lens |\r\n|--------------|-------------|\r\n| Thinner at center, thicker at edges | Thicker at center, thinner at edges |\r\n| Diverges parallel rays | Converges parallel rays |\r\n| Always forms virtual images | Forms real and virtual images |\r\n| Has negative power | Has positive power |\r\n\r\n**d. Real and Apparent Depth**\r\n\r\n| Real Depth | Apparent Depth |\r\n|------------|----------------|\r\n| Actual depth of object in medium | Depth as seen by observer |\r\n| Does not change | Changes due to refraction |\r\n| Example: Actual depth of pool | Example: Pool appears shallow |\r\n\r\n---\r\n\r\n### **4. Give reasons:**\r\n\r\n**a. A concave mirror is used in headlights of cars.**\r\n\r\n**Answer:** Because concave mirror produces powerful parallel beam of light when bulb is placed at focus.\r\n\r\n**b. Convex mirrors are used as rear-view mirrors in vehicles.**\r\n\r\n**Answer:** Because convex mirrors give wider field of view and always form erect, virtual images.\r\n\r\n**c. A ray passing through center of curvature retraces its path.**\r\n\r\n**Answer:** Because it hits the mirror normally (perpendicular), so angle of incidence is 0°, hence angle of reflection is also 0°.\r\n\r\n**d. We can see our image in water.**\r\n\r\n**Answer:** Because water surface acts like a plane mirror due to total internal reflection.\r\n\r\n**e. A coin at the bottom of a glass appears to be raised when water is filled.**\r\n\r\n**Answer:** Due to refraction of light from water to air, the light rays bend away from normal making coin appear closer.\r\n\r\n**f. A thick glass slab appears thin when viewed from top.**\r\n\r\n**Answer:** Due to refraction, light bends when coming from glass to air, making the slab appear thinner.\r\n\r\n**g. Stars appear to twinkle.**\r\n\r\n**Answer:** Due to atmospheric refraction, starlight continuously changes its path, making stars appear to twinkle.\r\n\r\n**h. The sun is visible before actual sunrise and after actual sunset.**\r\n\r\n**Answer:** Due to atmospheric refraction, sunlight bends and reaches us even when sun is below horizon.\r\n\r\n**i. A lemon kept in water appears bigger than its actual size.**\r\n\r\n**Answer:** Water acts as a magnifying glass due to refraction, making objects appear larger.\r\n\r\n**j. Diamond sparkles brilliantly.**\r\n\r\n**Answer:** Due to high refractive index and total internal reflection, light undergoes multiple reflections inside diamond.\r\n\r\n---\r\n\r\n### **5. Numerical Problems:**\r\n\r\n#### **Problem Type 1: Mirror Formula**\r\n\r\n**Q1:** An object is placed 20 cm in front of a concave mirror of focal length 15 cm. Find the position and nature of image.\r\n\r\n**Given:**\r\n- u = -20 cm (object distance)\r\n- f = -15 cm (concave mirror)\r\n- v = ?\r\n\r\n**Solution:**\r\nUsing mirror formula: 1/f = 1/v + 1/u\r\n1/(-15) = 1/v + 1/(-20)\r\n1/v = -1/15 + 1/20 = (-4 + 3)/60 = -1/60\r\nv = -60 cm\r\n\r\n**Magnification:** m = -v/u = -(-60)/(-20) = -3\r\n\r\n**Answer:** Image is at 60 cm in front of mirror, real, inverted, and 3 times enlarged.\r\n\r\n**Q2:** A convex mirror has focal length 20 cm. Where should an object be placed to get an image at 12 cm behind the mirror?\r\n\r\n**Given:**\r\n- f = +20 cm (convex mirror)\r\n- v = +12 cm (behind mirror)\r\n- u = ?\r\n\r\n**Solution:**\r\n1/f = 1/v + 1/u\r\n1/20 = 1/12 + 1/u\r\n1/u = 1/20 - 1/12 = (3-5)/60 = -2/60 = -1/30\r\nu = -30 cm\r\n\r\n**Answer:** Object should be placed 30 cm in front of the mirror.\r\n\r\n#### **Problem Type 2: Lens Formula**\r\n\r\n**Q3:** A convex lens of focal length 25 cm forms an image at 50 cm. Find object distance and magnification.\r\n\r\n**Given:**\r\n- f = +25 cm (convex lens)\r\n- v = +50 cm (real image)\r\n- u = ?\r\n\r\n**Solution:**\r\n1/f = 1/v - 1/u\r\n1/25 = 1/50 - 1/u\r\n1/u = 1/50 - 1/25 = (1-2)/50 = -1/50\r\nu = -50 cm\r\n\r\n**Magnification:** m = v/u = 50/(-50) = -1\r\n\r\n**Answer:** Object distance = 50 cm, magnification = -1 (same size, inverted)\r\n\r\n**Q4:** A concave lens of focal length 20 cm forms an image 12 cm from lens. Find object distance.\r\n\r\n**Given:**\r\n- f = -20 cm (concave lens)\r\n- v = -12 cm (virtual image)\r\n- u = ?\r\n\r\n**Solution:**\r\n1/f = 1/v - 1/u\r\n1/(-20) = 1/(-12) - 1/u\r\n1/u = -1/12 - (-1/20) = -1/12 + 1/20 = (-5+3)/60 = -2/60 = -1/30\r\nu = -30 cm\r\n\r\n**Answer:** Object distance = 30 cm\r\n\r\n#### **Problem Type 3: Power of Lens**\r\n\r\n**Q5:** Find the power of a convex lens of focal length 50 cm.\r\n\r\n**Given:**\r\n- f = 50 cm = 0.5 m\r\n\r\n**Solution:**\r\nP = 1/f = 1/0.5 = 2 D\r\n\r\n**Answer:** Power = +2 D\r\n\r\n**Q6:** A concave lens has power -4 D. Find its focal length.\r\n\r\n**Given:**\r\n- P = -4 D\r\n\r\n**Solution:**\r\nP = 1/f\r\nf = 1/P = 1/(-4) = -0.25 m = -25 cm\r\n\r\n**Answer:** Focal length = 25 cm\r\n\r\n#### **Problem Type 4: Refractive Index**\r\n\r\n**Q7:** Light enters from air into glass. If angle of incidence is 45° and angle of refraction is 30°, find refractive index of glass.\r\n\r\n**Given:**\r\n- i = 45°, r = 30°\r\n- sin 45° = 0.707, sin 30° = 0.5\r\n\r\n**Solution:**\r\nμ = sin i/sin r = sin 45°/sin 30° = 0.707/0.5 = 1.414\r\n\r\n**Answer:** Refractive index of glass = 1.414\r\n\r\n**Q8:** Speed of light in water is 2.25 × 10⁸ m/s. Find refractive index of water.\r\n\r\n**Given:**\r\n- c = 3 × 10⁸ m/s\r\n- v = 2.25 × 10⁸ m/s\r\n\r\n**Solution:**\r\nμ = c/v = (3 × 10⁸)/(2.25 × 10⁸) = 1.33\r\n\r\n**Answer:** Refractive index of water = 1.33\r\n\r\n---\r\n\r\n## 📐 6. DIAGRAMMATIC QUESTIONS\r\n\r\n### **Question 1: Ray Diagram for Concave Mirror**\r\n**Draw ray diagram when object is placed between F and C of concave mirror.**\r\n\r\n**Answer:** \r\n- Object placed between F and C\r\n- Image formed beyond C\r\n- Image is real, inverted, and enlarged\r\n- Draw two rays: one parallel to axis, another through focus\r\n\r\n### **Question 2: Ray Diagram for Convex Lens**\r\n**Draw ray diagram when object is placed at 2F of convex lens.**\r\n\r\n**Answer:**\r\n- Object at 2F\r\n- Image formed at 2F on other side\r\n- Image is real, inverted, same size\r\n- Draw rays through optical center and parallel to axis\r\n\r\n### **Question 3: Refraction through Glass Slab**\r\n**Show the path of light ray through rectangular glass slab.**\r\n\r\n**Answer:**\r\n- Ray bends toward normal when entering glass\r\n- Ray travels straight inside glass\r\n- Ray bends away from normal when leaving glass\r\n- Emergent ray is parallel to incident ray but displaced\r\n\r\n---\r\n\r\n## 📈 7. IMPORTANT FORMULAS SUMMARY\r\n\r\n### **Mirror Formulas:**\r\n- Mirror formula: 1/f = 1/v + 1/u\r\n- Magnification: m = -v/u = h\'/h\r\n- Relation: f = R/2\r\n\r\n### **Lens Formulas:**\r\n- Lens formula: 1/f = 1/v - 1/u\r\n- Power: P = 1/f (in meters)\r\n- Magnification: m = v/u = h\'/h\r\n\r\n### **Refraction Formulas:**\r\n- Snell\'s law: sin i/sin r = μ\r\n- Refractive index: μ = c/v\r\n- Relative refractive index: ₁μ₂ = μ₂/μ₁\r\n\r\n### **Sign Conventions:**\r\n**Mirrors:** All distances from pole, real images have positive v\r\n**Lenses:** Object distance always negative, real images have positive v\r\n\r\n---\r\n\r\n## 🎯 8. EXAM PREPARATION TIPS\r\n\r\n### **Theory Questions (2-3 marks)**\r\n- Learn definitions with proper units\r\n- Understand laws of reflection and refraction\r\n- Practice distinguishing between concepts\r\n- Remember applications of mirrors and lenses\r\n\r\n### **Numerical Problems (3-4 marks)**\r\n- Memorize all formulas with correct signs\r\n- Apply sign conventions carefully\r\n- Show all calculation steps clearly\r\n- Check units in final answer\r\n\r\n### **Ray Diagrams (4-5 marks)**\r\n- Use ruler and pencil for neat diagrams\r\n- Show at least 2 rays for image formation\r\n- Mark all points and distances clearly\r\n- Write image characteristics\r\n\r\n### **Give Reason Questions (2-3 marks)**\r\n- Connect to daily life examples\r\n- Use scientific principles to explain\r\n- Mention relevant optical phenomena\r\n\r\n---\r\n\r\n## 🏆 9. PREVIOUS YEAR SEE QUESTIONS PATTERN\r\n\r\n### **Theory Questions:**\r\n- Laws of reflection and refraction\r\n- Types and uses of mirrors/lenses\r\n- Properties of images\r\n- Definitions of optical terms\r\n\r\n### **Numerical Questions:**\r\n- Mirror and lens formula problems\r\n- Power of lens calculations\r\n- Refractive index problems\r\n- Magnification calculations\r\n\r\n### **Diagram Questions:**\r\n- Ray diagrams for mirrors and lenses\r\n- Refraction through glass slab\r\n- Path of light in different media\r\n\r\n---\r\n\r\n## ✅ 10. CHAPTER CHECKLIST\r\n\r\n**Before SEE Exam, ensure you can:**\r\n- [ ] State laws of reflection and refraction\r\n- [ ] Draw ray diagrams for all cases\r\n- [ ] Apply mirror and lens formulas correctly\r\n- [ ] Calculate power and refractive index\r\n- [ ] Distinguish between optical concepts\r\n- [ ] Explain daily life optical phenomena\r\n- [ ] Solve all types of numerical problems\r\n- [ ] Remember uses of mirrors and lenses\r\n\r\n---\r\n\r\n## 🎊 CONCLUSION\r\n\r\nLight is one of the highest-scoring chapters if concepts and formulas are mastered properly. Focus on understanding ray diagrams, applying correct sign conventions, and connecting theory to practical applications. Practice numerical problems regularly and draw neat diagrams for maximum marks.\r\n\r\n**Success Formula:** \r\nClear Concepts + Formula Practice + Diagram Skills + Application Knowledge = Perfect SEE Score!\r\n\r\n---\r\n\r\n*This complete note covers all exercises from the Light chapter of NEB Science textbook for SEE examination preparation. Study systematically and practice regularly for excellent results.*\r\n\r\n**📞 Need Help?** Practice more ray diagrams and numerical problems for complete mastery of this important chapter.\r\n\r\n---', 1, '2025-07-25 01:11:38', '2025-09-16 03:05:11');
INSERT INTO `course_notes_content` (`id`, `topic_id`, `content`, `markdown_format`, `created_at`, `updated_at`) VALUES
(84, 11404, '# Heat - Grade 10 (SEE) Physics\r\n## Complete Chapter Notes with All Exercises - NEB Curriculum 2080\r\n\r\n---\r\n\r\n## 🎯 Chapter Overview\r\nStep into the intriguing realm of **Heat Class 10 Science** as we explore the fascinating world of thermal energy! This comprehensive chapter provides deep insights into the nature of heat and its applications in our everyday lives. From understanding temperature to exploring heat transfer mechanisms, this chapter delves into the fundamental principles of heat in a clear and engaging manner.\r\n\r\n**Weightage:** 12-15 marks in SEE examination\r\n**Time Required:** 25-30 periods\r\n\r\n---\r\n\r\n## 📚 Learning Objectives\r\nAfter studying this chapter, students will be able to:\r\n- Understand the concept of heat as a form of energy\r\n- Distinguish between heat and temperature clearly\r\n- Apply the heat equation to solve numerical problems\r\n- Explain different modes of heat transfer\r\n- Understand calorimetry principles\r\n- Analyze anomalous expansion of water\r\n\r\n---\r\n\r\n## 🔥 1. INTRODUCTION TO HEAT\r\n\r\n### 1.1 Definition of Heat\r\nHeat is a form of energy that gives us the sensation of warmth. Heat is the **sum total of kinetic energy** contained by the molecules in a body.\r\n\r\n**Modern Definition:** Heat is the energy transferred due to temperature difference between two systems.\r\n\r\n### 1.2 Heat as Energy\r\nHeat energy is produced when molecules in a body start vibrating or moving around. The faster the molecules move, the more heat is produced in that body.\r\n\r\n**Key Points:**\r\n- Heat always flows from hotter body to colder body\r\n- Heat is a cause, temperature is an effect\r\n- Amount of heat depends on mass and average kinetic energy of molecules\r\n\r\n### 1.3 Units of Heat\r\n**SI Unit:** Joule (J)\r\n**CGS Unit:** Calorie (cal)\r\n\r\n**Relationship:** \r\n```\r\n4.2 J = 1 cal\r\n1 cal = 4.2 J\r\n```\r\n\r\n**Definition of Calorie:** The amount of heat required to raise the temperature of 1 gram of pure water by 1°C at standard atmospheric pressure.\r\n\r\n### 1.4 Device to Measure Heat\r\n**Calorimeter** is used to measure heat energy of a body.\r\n\r\n---\r\n\r\n## 🌡️ 2. TEMPERATURE\r\n\r\n### 2.1 Definition\r\nTemperature is the measure of how hot or cold a body is. It is the **average kinetic energy** of molecules present in a body.\r\n\r\n### 2.2 Difference Between Heat and Temperature\r\n\r\n| Heat | Temperature |\r\n|------|-------------|\r\n| Sum of kinetic energy of molecules | Average kinetic energy of molecules |\r\n| SI unit: Joule (J) | SI unit: Kelvin (K) |\r\n| Measured by calorimeter | Measured by thermometer |\r\n| It is a cause | It is an effect |\r\n| It flows from one body to another | It doesn\'t flow |\r\n| Depends on mass of body | Independent of mass |\r\n| Energy form | Degree of hotness/coldness |\r\n\r\n### 2.3 Temperature Scales\r\n**Three temperature scales:**\r\n1. **Celsius Scale (°C):** Lower fixed point = 0°C, Upper fixed point = 100°C\r\n2. **Fahrenheit Scale (°F):** Lower fixed point = 32°F, Upper fixed point = 212°F\r\n3. **Kelvin Scale (K):** Lower fixed point = 273K, Upper fixed point = 373K\r\n\r\n### 2.4 Temperature Conversion Formula\r\n```\r\n(C - 0)/100 = (F - 32)/180 = (K - 273)/100\r\n```\r\n\r\n**Simplified Relations:**\r\n- C = (F - 32) × 5/9\r\n- F = (C × 9/5) + 32\r\n- K = C + 273\r\n\r\n### 2.5 Thermometer\r\n**Device:** Thermometer is used to measure temperature\r\n**Principle:** \"Substances expand on heating and contract on cooling\"\r\n**Normal human body temperature:** 37°C or 98.6°F\r\n\r\n---\r\n\r\n## ⚖️ 3. HEAT EQUATION\r\n\r\n### 3.1 Derivation of Heat Equation\r\nLet a body of mass \'m\' have initial temperature \'t₁\' and final temperature \'t₂\' when heat \'Q\' is supplied.\r\n\r\n**Heat gained/lost (Q) ∝ mass of body (m)**  ... (i)\r\n**Heat gained/lost (Q) ∝ change in temperature (Δt)** ... (ii)\r\n\r\nCombining (i) and (ii):\r\n**Q ∝ m × Δt**\r\n\r\nTherefore: **Q = ms Δt**\r\n\r\nWhere \'s\' is the specific heat capacity of the substance.\r\n\r\n### 3.2 Heat Equation Formula\r\n```\r\nQ = ms Δt\r\n\r\nWhere:\r\nQ = Amount of heat (J)\r\nm = Mass of body (kg)\r\ns = Specific heat capacity (J/kg°C)\r\nΔt = Change in temperature (°C)\r\n```\r\n\r\n---\r\n\r\n## 🔬 4. SPECIFIC HEAT CAPACITY\r\n\r\n### 4.1 Definition\r\nSpecific heat capacity is the amount of heat gained or lost by a substance of mass 1 kg to change its temperature by 1°C or 1K.\r\n\r\n**Formula:**\r\n```\r\ns = Q/(m × Δt)\r\n\r\nSI Unit: J/kg°C\r\n```\r\n\r\n### 4.2 Physical Meaning\r\n**When we say specific heat capacity of water is 4200 J/kg°C:**\r\nThis means 4200 J of energy is needed to raise the temperature of 1 kg of water by 1°C.\r\n\r\n### 4.3 Properties\r\n- Different substances have different specific heat capacities\r\n- Substances with higher specific heat capacity heat up and cool down slowly\r\n- Substances with lower specific heat capacity heat up and cool down quickly\r\n- Water has the highest specific heat capacity (4200 J/kg°C)\r\n\r\n---\r\n\r\n## 🔄 5. PRINCIPLE OF CALORIMETRY\r\n\r\n### 5.1 Statement\r\n**\"The amount of heat lost by a hotter body is equal to the amount of heat gained by a colder body when they are kept in thermal contact.\"**\r\n\r\n**Mathematical Expression:**\r\n```\r\nHeat lost = Heat gained\r\nm₁s₁Δt₁ = m₂s₂Δt₂\r\n```\r\n\r\n### 5.2 Applications\r\n- Used in calorimeter to measure heat\r\n- Mixing of hot and cold liquids\r\n- Heat transfer calculations\r\n- Finding specific heat capacity of substances\r\n\r\n---\r\n\r\n## 🌊 6. ANOMALOUS EXPANSION OF WATER\r\n\r\n### 6.1 Definition\r\nThe unusual behavior of water between 0°C to 4°C is called anomalous expansion of water.\r\n\r\n### 6.2 Behavior\r\n**Normal Expansion:** Substances expand on heating and contract on cooling\r\n**Anomalous Expansion:** Water contracts when heated from 0°C to 4°C and expands when cooled from 4°C to 0°C\r\n\r\n### 6.3 Key Points\r\n- Water has **maximum density** at 4°C\r\n- Water has **minimum volume** at 4°C\r\n- Below 4°C, water expands instead of contracting\r\n- Above 4°C, water shows normal expansion\r\n\r\n### 6.4 Significance\r\n**Preservation of Aquatic Life:**\r\n- In winter, water at 4°C (densest) stays at the bottom\r\n- Ice forms on the surface first\r\n- Ice acts as insulator, protecting aquatic life below\r\n- This prevents complete freezing of water bodies\r\n\r\n---\r\n\r\n## 🔥 7. HEAT TRANSFER\r\n\r\n### 7.1 Modes of Heat Transfer\r\nHeat can be transferred by three methods:\r\n1. **Conduction**\r\n2. **Convection** \r\n3. **Radiation**\r\n\r\n### 7.2 Conduction\r\n**Definition:** Transfer of heat through a material without movement of the material itself.\r\n\r\n**Process:** Heat transfers through molecular vibrations and collisions\r\n**Medium:** Mainly occurs in solids\r\n**Example:** Heat transfer through metal rod\r\n\r\n**Characteristics:**\r\n- Requires direct contact\r\n- No movement of particles\r\n- Efficient in metals (good conductors)\r\n- Poor in non-metals (insulators)\r\n\r\n### 7.3 Convection\r\n**Definition:** Transfer of heat through movement of fluids (liquids and gases).\r\n\r\n**Process:** Hot fluid becomes less dense, rises up; cold fluid becomes denser, sinks down\r\n**Medium:** Occurs in liquids and gases\r\n**Example:** Heating water in a pot, air circulation\r\n\r\n**Characteristics:**\r\n- Requires movement of fluid particles\r\n- Creates convection currents\r\n- Cannot occur in solids\r\n- Natural and forced convection possible\r\n\r\n### 7.4 Radiation\r\n**Definition:** Transfer of heat through electromagnetic waves without requiring any medium.\r\n\r\n**Process:** Heat transfers through electromagnetic radiation\r\n**Medium:** Can occur in vacuum (no medium required)\r\n**Example:** Heat from sun, heat from fire\r\n\r\n**Characteristics:**\r\n- Fastest mode of heat transfer\r\n- Can travel through vacuum\r\n- All objects emit and absorb radiation\r\n- Follows laws of reflection and refraction\r\n\r\n### 7.5 Comparison of Heat Transfer Methods\r\n\r\n| Conduction | Convection | Radiation |\r\n|------------|------------|-----------|\r\n| Through direct contact | Through fluid movement | Through electromagnetic waves |\r\n| Mainly in solids | In liquids and gases | In all media including vacuum |\r\n| Particles don\'t move | Particles move | No particles required |\r\n| Slowest | Moderate speed | Fastest |\r\n| Does not follow reflection laws | Does not follow reflection laws | Follows reflection laws |\r\n\r\n---\r\n\r\n## 📋 8. COMPLETE EXERCISE SOLUTIONS\r\n\r\n### **1. Choose the correct options:**\r\n\r\n**a. Which statement defines heat?**\r\n(i) total kinetic energy of molecules ✓\r\n(ii) average kinetic energy of molecules\r\n(iii) sum of kinetic energy and potential energy\r\n(iv) energy transmitted due to difference in temperature\r\n\r\n**Answer:** (i) total kinetic energy of molecules\r\n\r\n**b. The SI unit of heat is:**\r\n(i) calorie (ii) joule ✓ (iii) watt (iv) pascal\r\n\r\n**Answer:** (ii) joule\r\n\r\n**c. Specific heat capacity depends on:**\r\n(i) mass (ii) volume (iii) temperature (iv) nature of substance ✓\r\n\r\n**Answer:** (iv) nature of substance\r\n\r\n**d. Water has maximum density at:**\r\n(i) 0°C (ii) 4°C ✓ (iii) 100°C (iv) 37°C\r\n\r\n**Answer:** (ii) 4°C\r\n\r\n### **2. Answer the following questions:**\r\n\r\n**a. Define heat. Write its SI unit.**\r\n\r\n**Answer:** Heat is a form of energy that gives sensation of warmth OR the sum of kinetic energy of molecules present in a body.\r\n**SI Unit:** Joule (J)\r\n\r\n**b. What is temperature? How is it measured?**\r\n\r\n**Answer:** Temperature is the measure of hotness or coldness of a body OR average kinetic energy of molecules in a body.\r\n**Measurement:** Temperature is measured using thermometer.\r\n\r\n**c. Write the relationship between joule and calorie.**\r\n\r\n**Answer:** 4.2 J = 1 cal or 1 cal = 4.2 J\r\n\r\n**d. State the principle of calorimetry.**\r\n\r\n**Answer:** The principle of calorimetry states that \"The amount of heat lost by hotter body equals the amount of heat gained by colder body when they are in thermal contact.\"\r\n\r\n**e. Define specific heat capacity. Write its SI unit.**\r\n\r\n**Answer:** Specific heat capacity is the amount of heat required to raise the temperature of 1 kg of substance by 1°C or 1K.\r\n**SI Unit:** J/kg°C\r\n\r\n**f. What is anomalous expansion of water?**\r\n\r\n**Answer:** The unusual behavior of water between 0°C to 4°C where it contracts on heating and expands on cooling is called anomalous expansion of water.\r\n\r\n**g. Name the three modes of heat transfer.**\r\n\r\n**Answer:** \r\n1. Conduction\r\n2. Convection\r\n3. Radiation\r\n\r\n**h. Convert 25°C into Fahrenheit scale.**\r\n\r\n**Solution:**\r\nGiven: C = 25°C, F = ?\r\n\r\nUsing: (C - 0)/100 = (F - 32)/180\r\n(25 - 0)/100 = (F - 32)/180\r\n25/100 = (F - 32)/180\r\nF - 32 = (25 × 180)/100 = 45\r\nF = 45 + 32 = 77°F\r\n\r\n**Answer:** 25°C = 77°F\r\n\r\n### **3. Distinguish between:**\r\n\r\n**a. Heat and Temperature**\r\n\r\n| Heat | Temperature |\r\n|------|-------------|\r\n| Sum of kinetic energy | Average kinetic energy |\r\n| SI unit: Joule | SI unit: Kelvin |\r\n| Measured by calorimeter | Measured by thermometer |\r\n| Cause | Effect |\r\n| Flows from one body to another | Doesn\'t flow |\r\n\r\n**b. Conduction and Convection**\r\n\r\n| Conduction | Convection |\r\n|------------|------------|\r\n| Heat transfer through direct contact | Heat transfer through fluid movement |\r\n| Occurs mainly in solids | Occurs in liquids and gases |\r\n| No movement of particles | Movement of particles occurs |\r\n| Slower process | Faster than conduction |\r\n\r\n**c. Good conductors and Bad conductors**\r\n\r\n| Good Conductors | Bad Conductors (Insulators) |\r\n|-----------------|---------------------------|\r\n| Allow heat to pass easily | Do not allow heat to pass easily |\r\n| Examples: Metals (copper, iron) | Examples: Wood, plastic, air |\r\n| Have free electrons | No free electrons |\r\n| Used in cooking utensils | Used for insulation |\r\n\r\n### **4. Give reasons:**\r\n\r\n**a. Metals are good conductors of heat.**\r\n\r\n**Answer:** Metals have free electrons that can move easily and transfer kinetic energy from one atom to another, making them good conductors of heat.\r\n\r\n**b. Water is used in car radiators.**\r\n\r\n**Answer:** Water has high specific heat capacity (4200 J/kg°C), so it can absorb large amount of heat with small temperature rise, making it effective coolant.\r\n\r\n**c. We feel cool under a tree.**\r\n\r\n**Answer:** Trees provide shade, blocking direct sun\'s radiation. Also, transpiration from leaves cools the surrounding air through evaporation.\r\n\r\n**d. Ice floats on water.**\r\n\r\n**Answer:** Due to anomalous expansion, ice has lower density than water at 0°C, so it floats on water surface.\r\n\r\n**e. Aquatic animals can survive in frozen lakes.**\r\n\r\n**Answer:** Due to anomalous expansion of water, ice forms only on the surface while water remains liquid below, allowing aquatic life to survive.\r\n\r\n**f. We can see the heat waves above a hot road.**\r\n\r\n**Answer:** Hot air above the road has different density than cooler air, causing light to bend and creating visible heat waves through refraction.\r\n\r\n**g. Woolen clothes keep us warm in winter.**\r\n\r\n**Answer:** Wool traps air between its fibers. Air is a poor conductor of heat, so it acts as insulation, preventing body heat from escaping.\r\n\r\n### **5. Numerical Problems:**\r\n\r\n#### **Problem Type 1: Heat Equation**\r\n\r\n**Q1:** Calculate the amount of heat required to change temperature of 3 kg iron from 30°C to 200°C. (Specific heat capacity of iron = 460 J/kg°C)\r\n\r\n**Given:**\r\n- m = 3 kg\r\n- Initial temperature (t₁) = 30°C\r\n- Final temperature (t₂) = 200°C\r\n- s = 460 J/kg°C\r\n\r\n**Solution:**\r\nΔt = t₂ - t₁ = 200 - 30 = 170°C\r\nQ = msΔt = 3 × 460 × 170 = 234,600 J\r\n\r\n**Answer:** Heat required = 234,600 J or 234.6 kJ\r\n\r\n**Q2:** 2400 J heat is given to 2 kg iron at 20°C. Find final temperature. (s = 460 J/kg°C)\r\n\r\n**Given:**\r\n- Q = 2400 J\r\n- m = 2 kg\r\n- t₁ = 20°C\r\n- s = 460 J/kg°C\r\n\r\n**Solution:**\r\nQ = msΔt\r\n2400 = 2 × 460 × (t₂ - 20)\r\n2400 = 920 × (t₂ - 20)\r\nt₂ - 20 = 2400/920 = 2.61\r\nt₂ = 20 + 2.61 = 22.61°C\r\n\r\n**Answer:** Final temperature = 22.61°C\r\n\r\n#### **Problem Type 2: Calorimetry**\r\n\r\n**Q3:** Hot water at 100°C is mixed with 300g of water at 0°C until final temperature becomes 40°C. Find mass of hot water added.\r\n\r\n**Given:**\r\n- Hot water temperature = 100°C\r\n- Cold water mass = 300g = 0.3 kg\r\n- Cold water temperature = 0°C\r\n- Final temperature = 40°C\r\n\r\n**Solution:**\r\nLet mass of hot water = m₁\r\n\r\nUsing principle of calorimetry:\r\nHeat lost by hot water = Heat gained by cold water\r\nm₁ × s × (100 - 40) = 0.3 × s × (40 - 0)\r\nm₁ × 60 = 0.3 × 40\r\nm₁ = (0.3 × 40)/60 = 0.2 kg\r\n\r\n**Answer:** Mass of hot water = 0.2 kg or 200g\r\n\r\n**Q4:** Find specific heat capacity of water if 2.1 × 10⁵ J heat raises temperature of 2 kg water from 40°C to 65°C.\r\n\r\n**Given:**\r\n- Q = 2.1 × 10⁵ J\r\n- m = 2 kg\r\n- t₁ = 40°C, t₂ = 65°C\r\n\r\n**Solution:**\r\nΔt = 65 - 40 = 25°C\r\ns = Q/(m × Δt) = (2.1 × 10⁵)/(2 × 25) = 210,000/50 = 4200 J/kg°C\r\n\r\n**Answer:** Specific heat capacity = 4200 J/kg°C\r\n\r\n#### **Problem Type 3: Temperature Conversion**\r\n\r\n**Q5:** Convert 37°C to Fahrenheit scale.\r\n\r\n**Solution:**\r\nF = (C × 9/5) + 32 = (37 × 9/5) + 32 = 66.6 + 32 = 98.6°F\r\n\r\n**Answer:** 37°C = 98.6°F\r\n\r\n**Q6:** Convert 273K to Celsius scale.\r\n\r\n**Solution:**\r\nC = K - 273 = 273 - 273 = 0°C\r\n\r\n**Answer:** 273K = 0°C\r\n\r\n#### **Problem Type 4: Mixed Problems**\r\n\r\n**Q7:** How much heat is needed to raise temperature of 5 kg water from 20°C to 100°C?\r\n\r\n**Given:**\r\n- m = 5 kg\r\n- t₁ = 20°C, t₂ = 100°C\r\n- s = 4200 J/kg°C\r\n\r\n**Solution:**\r\nQ = msΔt = 5 × 4200 × (100 - 20) = 5 × 4200 × 80 = 1,680,000 J = 1680 kJ\r\n\r\n**Answer:** Heat required = 1680 kJ\r\n\r\n**Q8:** If 50,000 J heat is supplied to 10 kg water, what is the rise in temperature?\r\n\r\n**Given:**\r\n- Q = 50,000 J\r\n- m = 10 kg\r\n- s = 4200 J/kg°C\r\n\r\n**Solution:**\r\nΔt = Q/(ms) = 50,000/(10 × 4200) = 50,000/42,000 = 1.19°C\r\n\r\n**Answer:** Temperature rise = 1.19°C\r\n\r\n---\r\n\r\n## 📈 9. IMPORTANT FORMULAS SUMMARY\r\n\r\n### **Heat and Temperature**\r\n- Q = msΔt (Heat equation)\r\n- s = Q/(mΔt) (Specific heat capacity)\r\n- (C-0)/100 = (F-32)/180 = (K-273)/100 (Temperature conversion)\r\n\r\n### **Temperature Conversions**\r\n- F = (C × 9/5) + 32\r\n- C = (F - 32) × 5/9\r\n- K = C + 273\r\n\r\n### **Calorimetry**\r\n- Heat lost = Heat gained\r\n- m₁s₁Δt₁ = m₂s₂Δt₂\r\n\r\n### **Constants**\r\n- 1 cal = 4.2 J\r\n- Specific heat of water = 4200 J/kg°C\r\n- Water density maximum at 4°C\r\n\r\n---\r\n\r\n## 🎯 10. EXAM PREPARATION TIPS\r\n\r\n### **Theory Questions (2-3 marks)**\r\n- Learn exact definitions with SI units\r\n- Understand anomalous expansion clearly\r\n- Practice temperature conversion formulas\r\n- Remember all three modes of heat transfer\r\n\r\n### **Numerical Problems (3-4 marks)**\r\n- Master the heat equation Q = msΔt\r\n- Practice calorimetry problems extensively\r\n- Temperature conversion problems are common\r\n- Show all calculation steps clearly\r\n\r\n### **Give Reason Questions (2-3 marks)**\r\n- Connect to daily life examples\r\n- Use scientific principles to explain\r\n- Focus on anomalous expansion applications\r\n- Explain heat transfer in real situations\r\n\r\n### **Long Questions (5-6 marks)**\r\n- Complete derivation of heat equation\r\n- Detailed explanation of calorimetry principle\r\n- Modes of heat transfer with examples\r\n- Anomalous expansion and its significance\r\n\r\n---\r\n\r\n## 🏆 11. PREVIOUS YEAR SEE QUESTIONS PATTERN\r\n\r\n### **Theory Questions**\r\n- Definition of heat and temperature\r\n- Principle of calorimetry\r\n- Anomalous expansion of water\r\n- Modes of heat transfer\r\n- Specific heat capacity concept\r\n\r\n### **Numerical Questions**\r\n- Heat equation problems\r\n- Temperature conversion\r\n- Calorimetry calculations\r\n- Specific heat capacity finding\r\n- Mixed hot and cold water problems\r\n\r\n### **Common Diagrams**\r\n- Temperature vs time graph for water\r\n- Heat transfer modes illustration\r\n- Calorimeter diagram\r\n- Anomalous expansion graph\r\n\r\n---\r\n\r\n## ✅ 12. CHAPTER CHECKLIST\r\n\r\n**Before SEE Exam, ensure you can:**\r\n- [ ] Define heat and temperature clearly\r\n- [ ] Apply heat equation Q = msΔt correctly\r\n- [ ] Solve calorimetry problems step by step\r\n- [ ] Convert between temperature scales\r\n- [ ] Explain anomalous expansion of water\r\n- [ ] Describe all three heat transfer modes\r\n- [ ] Give scientific reasons for daily phenomena\r\n- [ ] Draw and interpret temperature graphs\r\n\r\n---\r\n\r\n## 🎊 CONCLUSION\r\n\r\nHeat is a fundamental chapter that connects thermal energy concepts with daily life applications. The chapter builds strong foundation for understanding energy transfer, temperature effects, and thermal properties of matter. Master the heat equation, practice numerical problems regularly, and understand the scientific explanations behind everyday thermal phenomena.\r\n\r\n**Success Formula:** \r\nClear Concepts + Formula Practice + Daily Life Connections = Perfect Heat Mastery!\r\n\r\n---\r\n\r\n*This comprehensive note covers the complete Heat chapter as per NEB curriculum 2080, designed to enhance your scientific knowledge and help you grasp the significance of heat in our everyday lives. Through detailed explanations and practical examples, unlock the secrets of thermal energy in an informative and enjoyable way!*\r\n\r\n**📞 Need Help?** Practice more numerical problems and focus on understanding the principle of calorimetry for complete chapter mastery.\r\n\r\n---', 1, '2025-07-25 01:11:38', '2025-09-16 03:05:11'),
(85, 11402, '# Pressure - Grade 10 (SEE) Physics\r\n## Complete Chapter Notes with All Exercises - NEB Curriculum 2080\r\n\r\n---\r\n\r\n## 🎯 Chapter Overview\r\n**The notes of Class 10 Pressure chapter are prepared by experienced student with detailed and step-by-step explanation of the concepts.** These comprehensive notes are constantly updated with the latest information on the subject and are available in various formats so that you can easily access them from your device.\r\n\r\n**The notes of Class 10 Pressure chapter are very helpful for students as it helps them to understand the concepts clearly.** The notes are prepared in such a way that even a novice student can quickly grasp the concepts. **The notes also provide the students with a good practice material that can help them to practice and consolidate their understanding of the topic. In addition, the notes also provide the students with solutions to the problems related to the topic.**\r\n\r\n**Weightage:** 12-15 marks in SEE examination\r\n**Time Required:** 25-30 periods\r\n\r\n---\r\n\r\n## 📚 Learning Objectives\r\nAfter studying this chapter, students will be able to:\r\n- Define pressure and understand its applications\r\n- Apply Pascal\'s law to hydraulic machines\r\n- Understand Archimedes\' principle and its applications\r\n- Explain flotation and sinking conditions\r\n- Calculate atmospheric pressure using barometer\r\n- Solve numerical problems related to pressure\r\n\r\n---\r\n\r\n## 🔧 1. INTRODUCTION TO PRESSURE\r\n\r\n### 1.1 Definition\r\n**Pressure is defined as the force acting normally (perpendicularly) per unit area.**\r\n\r\n**Formula:**\r\n```\r\nP = F/A\r\n\r\nWhere:\r\nP = Pressure (Pascal or N/m²)\r\nF = Force (Newton)\r\nA = Area (m²)\r\n```\r\n\r\n### 1.2 SI Unit\r\n**SI Unit:** Pascal (Pa) or N/m²\r\n**CGS Unit:** dyne/cm²\r\n\r\n**Definition of 1 Pascal:** 1 Pascal is the pressure exerted when a force of 1 Newton acts normally on an area of 1 square meter.\r\n\r\n### 1.3 Factors Affecting Pressure\r\n1. **Force:** Pressure is directly proportional to the applied force\r\n2. **Area:** Pressure is inversely proportional to the area\r\n\r\n**Examples in Daily Life:**\r\n- Sharp knife cuts easily (small area, high pressure)\r\n- Foundation of buildings are broad (large area, low pressure)\r\n- Pointed nails and pins penetrate easily\r\n\r\n---\r\n\r\n## 💧 2. LIQUID PRESSURE\r\n\r\n### 2.1 Definition\r\nThe pressure exerted by a liquid at rest is called liquid pressure.\r\n\r\n### 2.2 Characteristics of Liquid Pressure\r\n1. **Liquid pressure increases with depth**\r\n2. **Liquid pressure depends on density of liquid**\r\n3. **Liquid pressure acts in all directions**\r\n4. **Liquid pressure is independent of the shape of container**\r\n5. **At the same depth, liquid pressure is same in all directions**\r\n\r\n### 2.3 Formula for Liquid Pressure\r\n```\r\nP = ρgh\r\n\r\nWhere:\r\nP = Liquid pressure (Pa)\r\nρ = Density of liquid (kg/m³)\r\ng = Acceleration due to gravity (m/s²)\r\nh = Height/depth of liquid (m)\r\n```\r\n\r\n### 2.4 Applications\r\n- Water tanks are built at height to create pressure\r\n- Dams are made thicker at the bottom\r\n- Deep sea diving requires special equipment\r\n\r\n---\r\n\r\n## ⚖️ 3. PASCAL\'S LAW\r\n\r\n### 3.1 Statement\r\n**Pascal\'s Law states that \"When pressure is applied at a point on a liquid kept inside a closed container, then the pressure is transmitted equally and normally in all directions.\"**\r\n\r\nThis law is also called the **principle of transmission of liquid pressure**.\r\n\r\n### 3.2 Mathematical Expression\r\n```\r\nP₁ = P₂\r\nF₁/A₁ = F₂/A₂\r\nF₂ = (F₁ × A₂)/A₁\r\n```\r\n\r\n### 3.3 Applications of Pascal\'s Law\r\n\r\n#### A. Hydraulic Press\r\n- **Working Principle:** Small force applied on small piston creates large force on big piston\r\n- **Use:** Compressing materials, making sheets\r\n\r\n#### B. Hydraulic Lift\r\n- **Working Principle:** Small force lifts heavy vehicles\r\n- **Use:** Car service stations, elevators\r\n\r\n#### C. Hydraulic Brake\r\n- **Working Principle:** Force applied on brake pedal is transmitted to all wheels\r\n- **Use:** Vehicle braking system\r\n\r\n#### D. Hydraulic Jack\r\n- **Working Principle:** Small effort lifts heavy loads\r\n- **Use:** Lifting cars for repair\r\n\r\n### 3.4 Why Hydraulic Machine is Called Force Multiplier\r\n```\r\nSince F₂ = (F₁ × A₂)/A₁\r\nIf A₂ > A₁, then F₂ > F₁\r\n\r\nTherefore, a small force F₁ produces a large force F₂\r\n```\r\n\r\n---\r\n\r\n## 🌊 4. UPTHRUST (BUOYANCY)\r\n\r\n### 4.1 Definition\r\n**When a body is partially or completely immersed in liquid, it experiences an upward force, which is called upthrust or buoyant force.**\r\n\r\n**SI Unit:** Newton (N)\r\n\r\n### 4.2 Factors Affecting Upthrust\r\n1. **Density of liquid (ρ):** Greater density → Greater upthrust\r\n2. **Volume of displaced liquid (V):** Greater volume → Greater upthrust  \r\n3. **Acceleration due to gravity (g):** Greater g → Greater upthrust\r\n\r\n**Formula:**\r\n```\r\nU = V × ρ × g\r\n\r\nWhere:\r\nU = Upthrust (N)\r\nV = Volume of displaced liquid (m³)\r\nρ = Density of liquid (kg/m³)\r\ng = Acceleration due to gravity (m/s²)\r\n```\r\n\r\n### 4.3 Effects of Upthrust\r\n- Body appears lighter in liquid\r\n- **Apparent weight = Actual weight - Upthrust**\r\n- **Loss in weight = Upthrust**\r\n\r\n---\r\n\r\n## 🔬 5. ARCHIMEDES\' PRINCIPLE\r\n\r\n### 5.1 Statement\r\n**\"When a body is partially or completely immersed in a fluid, it experiences an upthrust which is equal to the weight of the fluid displaced by it.\"**\r\n\r\n### 5.2 Mathematical Expression\r\n```\r\nUpthrust = Weight of displaced fluid\r\nU = V × ρ × g\r\n\r\nWhere:\r\nV = Volume of displaced fluid\r\nρ = Density of fluid\r\ng = Acceleration due to gravity\r\n```\r\n\r\n### 5.3 Applications of Archimedes\' Principle\r\n1. **Ship and Boat floating**\r\n2. **Submarine diving and surfacing**\r\n3. **Hot air balloon flying**\r\n4. **Lactometer** (measuring density of milk)\r\n5. **Hydrometer** (measuring liquid density)\r\n\r\n---\r\n\r\n## 🏊 6. FLOTATION\r\n\r\n### 6.1 Law of Flotation\r\n**\"A floating body displaces fluid equal to its weight.\"**\r\n\r\n**Mathematical Expression:**\r\n```\r\nWeight of floating body = Weight of displaced fluid\r\nmg = V × ρ_fluid × g\r\n```\r\n\r\n### 6.2 Conditions for Floating and Sinking\r\n\r\n#### For Floating:\r\n- **Upthrust ≥ Weight of body**\r\n- **Density of body < Density of fluid**\r\n\r\n#### For Sinking:\r\n- **Upthrust < Weight of body**\r\n- **Density of body > Density of fluid**\r\n\r\n#### For Complete Immersion:\r\n- **Upthrust = Weight of body**\r\n- **Density of body = Density of fluid**\r\n\r\n### 6.3 Applications\r\n- **Ships float** because they displace water equal to their weight\r\n- **Ice floats on water** because density of ice < density of water\r\n- **Iron nail sinks** because density of iron > density of water\r\n\r\n---\r\n\r\n## 🌡️ 7. ATMOSPHERIC PRESSURE\r\n\r\n### 7.1 Definition\r\n**The pressure exerted by the atmosphere due to its weight is called atmospheric pressure.**\r\n\r\n### 7.2 Value\r\n- **Standard atmospheric pressure = 76 cm of Hg = 760 mm of Hg**\r\n- **= 1.01 × 10⁵ Pa = 101.3 kPa**\r\n\r\n### 7.3 Measurement of Atmospheric Pressure\r\n\r\n#### A. Mercury Barometer\r\n- **Working Principle:** Atmospheric pressure balances mercury column height\r\n- **Standard height:** 76 cm of mercury at sea level\r\n\r\n**Formula:**\r\n```\r\nP_atmospheric = ρ_mercury × g × h\r\n\r\nWhere:\r\nρ_mercury = 13,600 kg/m³\r\nh = height of mercury column\r\n```\r\n\r\n#### B. Applications\r\n- **Weather forecasting**\r\n- **Altitude measurement**\r\n- **Pressure measurement**\r\n\r\n### 7.4 Variation of Atmospheric Pressure\r\n- **Decreases with altitude**\r\n- **Changes with weather conditions**\r\n- **Higher at sea level, lower at mountains**\r\n\r\n---\r\n\r\n## 📋 8. COMPLETE EXERCISE SOLUTIONS\r\n\r\n### **1. Choose the correct options:**\r\n\r\n**a. On which law/principle is a lactometer based?**\r\n(i) Pascal\'s law (ii) Law of Gravitation (iii) Archimedes\' principle ✓ (iv) Newton\'s law\r\n\r\n**Answer:** (iii) Archimedes\' principle\r\n\r\n**b. What is the condition for flying a hydrogen balloon upwards in the air?**\r\n(i) weight of the balloon = weight of air displaced\r\n(ii) weight of balloon > weight of air displaced  \r\n(iii) weight of the balloon = volume of air displaced\r\n(iv) weight of balloon < weight of air displaced ✓\r\n\r\n**Answer:** (iv) weight of balloon < weight of air displaced\r\n\r\n**c. A ship sails from sea water to river water. What happens?**\r\n(i) ship rises up (ii) ship sinks down ✓ (iii) no change (iv) depends on load\r\n\r\n**Answer:** (ii) ship sinks down\r\n\r\n**d. The density of seawater is:**\r\n(i) less than river water (ii) more than river water ✓ (iii) equal to river water (iv) variable\r\n\r\n**Answer:** (ii) more than river water\r\n\r\n### **2. Answer the following questions:**\r\n\r\n**a. What is pressure? Write its SI unit.**\r\n\r\n**Answer:** Pressure is the force acting normally (perpendicularly) per unit area.\r\n**Formula:** P = F/A\r\n**SI Unit:** Pascal (Pa) or N/m²\r\n\r\n**b. Define 1 Pascal.**\r\n\r\n**Answer:** 1 Pascal is defined as the pressure exerted by 1 Newton force on the unit area (1 m²).\r\n**Mathematical:** If F = 1N and A = 1 m², then pressure = 1 Pascal\r\n\r\n**c. Write three properties of liquid pressure.**\r\n\r\n**Answer:**\r\n1. Liquid pressure is directly proportional to the depth of liquid\r\n2. Liquid pressure is directly proportional to the density of liquid  \r\n3. Liquid pressure is independent of the shape of container\r\n\r\n**d. State Pascal\'s law.**\r\n\r\n**Answer:** Pascal\'s law states that \"When pressure is applied at a point on a liquid kept inside a closed container, then the pressure is transmitted equally and normally in all directions.\"\r\n\r\n**e. Name four instruments that work on Pascal\'s law.**\r\n\r\n**Answer:**\r\n1. Hydraulic press\r\n2. Hydraulic lift\r\n3. Hydraulic brake\r\n4. Hydraulic jack\r\n\r\n**f. What is the working principle of hydraulic machines?**\r\n\r\n**Answer:** The working principle of hydraulic machines is:\r\n**Pressure on small piston = Pressure on big piston**\r\n**P₁ = P₂** or **F₁/A₁ = F₂/A₂**\r\n\r\n**g. Why is hydraulic machine called a force multiplier?**\r\n\r\n**Answer:** According to Pascal\'s law: F₁/A₁ = F₂/A₂\r\nTherefore: F₂ = (F₁ × A₂)/A₁\r\nSince A₂ > A₁, therefore F₂ > F₁\r\nSo, a small force F₁ produces a large force F₂, making it a force multiplier.\r\n\r\n**h. What is upthrust? Define upthrust.**\r\n\r\n**Answer:** When a body is partially or completely immersed in liquid, it experiences an upward force, which is called upthrust or buoyant force. Its SI unit is Newton.\r\n\r\n**i. What are the factors on which upthrust depends?**\r\n\r\n**Answer:** The factors on which upthrust depends are:\r\n1. Density of liquid (ρ)\r\n2. Volume of displaced liquid (V)  \r\n3. Acceleration due to gravity (g)\r\n**Formula:** U = V × ρ × g\r\n\r\n**j. State Archimedes\' principle.**\r\n\r\n**Answer:** Archimedes\' principle states that \"When a body is partially or completely immersed in water, it experiences an upthrust which is equal to the weight of the liquid displaced by it.\"\r\n\r\n**k. Name the forces acting on a body immersed in liquid.**\r\n\r\n**Answer:** The forces acting on a body immersed in liquid are:\r\n1. Weight of the body acting vertically downward\r\n2. Upthrust on body acting vertically upward\r\n\r\n**l. State the principle of flotation.**\r\n\r\n**Answer:** The principle of flotation states that \"A floating body displaces liquid equal to its weight.\"\r\n**Mathematical:** Weight of floating object = Weight of the liquid displaced\r\n\r\n**m. What is atmospheric pressure?**\r\n\r\n**Answer:** The pressure exerted by the atmosphere due to its weight is called atmospheric pressure.\r\n**Standard value:** 76 cm of Hg = 1.01 × 10⁵ Pa\r\n\r\n**n. How is atmospheric pressure measured?**\r\n\r\n**Answer:** Atmospheric pressure is measured using a mercury barometer. The standard atmospheric pressure supports 76 cm of mercury column at sea level.\r\n\r\n### **3. Distinguish between:**\r\n\r\n**a. Pressure and Upthrust**\r\n\r\n| Pressure | Upthrust |\r\n|----------|----------|\r\n| Force per unit area | Upward force on immersed body |\r\n| P = F/A | U = V × ρ × g |\r\n| SI unit: Pascal | SI unit: Newton |\r\n| Can act in any direction | Always acts upward |\r\n\r\n**b. Floating and Sinking**\r\n\r\n| Floating | Sinking |\r\n|----------|---------|\r\n| Upthrust ≥ Weight | Upthrust < Weight |\r\n| Density of body < Density of fluid | Density of body > Density of fluid |\r\n| Example: Wood in water | Example: Stone in water |\r\n| Body stays on surface | Body goes to bottom |\r\n\r\n**c. Pascal\'s Law and Archimedes\' Principle**\r\n\r\n| Pascal\'s Law | Archimedes\' Principle |\r\n|--------------|---------------------|\r\n| Pressure transmission in fluids | Upthrust on immersed body |\r\n| Applied to hydraulic machines | Applied to floating/sinking |\r\n| Pressure = Force/Area | Upthrust = Weight of displaced fluid |\r\n| Works on force multiplication | Works on buoyancy |\r\n\r\n### **4. Give reasons:**\r\n\r\n**a. A sharp knife cuts vegetables easily.**\r\n\r\n**Answer:** A sharp knife has a very small cutting area, so for the same applied force, the pressure becomes very high (P = F/A), making cutting easier.\r\n\r\n**b. The foundation of a building is made broader.**\r\n\r\n**Answer:** Broader foundation increases the contact area, which decreases the pressure on the ground (P = F/A), preventing the building from sinking.\r\n\r\n**c. A nail has a pointed end.**\r\n\r\n**Answer:** Pointed end has very small area, creating high pressure even with small force, making it easy to penetrate into materials.\r\n\r\n**d. Dams are made thicker at the bottom.**\r\n\r\n**Answer:** Liquid pressure increases with depth (P = ρgh), so the bottom of the dam experiences maximum pressure and needs to be thicker to withstand it.\r\n\r\n**e. It is difficult to push an empty can into water.**\r\n\r\n**Answer:** As the can is pushed deeper, the upthrust increases due to more water displacement, making it difficult to push further down.\r\n\r\n**f. We feel lighter in water.**\r\n\r\n**Answer:** When we are in water, we experience upthrust which acts upward, reducing our apparent weight, making us feel lighter.\r\n\r\n**g. A ship sinks more in fresh water than in sea water.**\r\n\r\n**Answer:** Sea water has higher density than fresh water, so it provides greater upthrust. To balance its weight, the ship needs to displace more fresh water, hence sinks deeper.\r\n\r\n**h. Ice floats on water.**\r\n\r\n**Answer:** The density of ice (917 kg/m³) is less than the density of water (1000 kg/m³), so ice floats on water.\r\n\r\n**i. A loaded ship is more submerged than an empty ship.**\r\n\r\n**Answer:** When loaded, the ship\'s weight increases. To balance this increased weight, more water must be displaced, so the ship sinks deeper.\r\n\r\n**j. An iron nail sinks in water but an iron ship floats.**\r\n\r\n**Answer:** Iron nail is solid and its density is greater than water, so it sinks. An iron ship is hollow and its overall density is less than water, so it floats.\r\n\r\n### **5. Numerical Problems:**\r\n\r\n#### **Problem Type 1: Pressure Calculation**\r\n\r\n**Q1:** Calculate the pressure produced when a force of 50 N is applied over an area of 10 m².\r\n\r\n**Given:**\r\n- Force (F) = 50 N\r\n- Area (A) = 10 m²\r\n\r\n**Solution:**\r\nP = F/A = 50/10 = 5 Pa\r\n\r\n**Answer:** Pressure = 5 Pa\r\n\r\n**Q2:** A force of 4 N acts on an area of 2 mm². Calculate the pressure.\r\n\r\n**Given:**\r\n- F = 4 N\r\n- A = 2 mm² = 2 × 10⁻⁶ m²\r\n\r\n**Solution:**\r\nP = F/A = 4/(2 × 10⁻⁶) = 2 × 10⁶ Pa = 2 MPa\r\n\r\n**Answer:** Pressure = 2 × 10⁶ Pa\r\n\r\n#### **Problem Type 2: Liquid Pressure**\r\n\r\n**Q3:** Calculate the pressure at a depth of 10 m in water. (Density of water = 1000 kg/m³, g = 9.8 m/s²)\r\n\r\n**Given:**\r\n- h = 10 m\r\n- ρ = 1000 kg/m³\r\n- g = 9.8 m/s²\r\n\r\n**Solution:**\r\nP = ρgh = 1000 × 9.8 × 10 = 98,000 Pa = 98 kPa\r\n\r\n**Answer:** Liquid pressure = 98 kPa\r\n\r\n**Q4:** At what depth in a liquid of density 800 kg/m³ will the pressure be 15,680 Pa?\r\n\r\n**Given:**\r\n- P = 15,680 Pa\r\n- ρ = 800 kg/m³\r\n- g = 9.8 m/s²\r\n\r\n**Solution:**\r\nh = P/(ρg) = 15,680/(800 × 9.8) = 15,680/7,840 = 2 m\r\n\r\n**Answer:** Depth = 2 m\r\n\r\n#### **Problem Type 3: Pascal\'s Law Problems**\r\n\r\n**Q5:** In a hydraulic press, the area of small piston is 2 cm² and large piston is 20 cm². If a force of 10 N is applied on small piston, find the force on large piston.\r\n\r\n**Given:**\r\n- A₁ = 2 cm²\r\n- A₂ = 20 cm²\r\n- F₁ = 10 N\r\n\r\n**Solution:**\r\nUsing Pascal\'s law: F₁/A₁ = F₂/A₂\r\nF₂ = (F₁ × A₂)/A₁ = (10 × 20)/2 = 100 N\r\n\r\n**Answer:** Force on large piston = 100 N\r\n\r\n**Q6:** A hydraulic lift has pistons of area 0.1 m² and 2 m². What force must be applied on small piston to lift a car of weight 8000 N?\r\n\r\n**Given:**\r\n- A₁ = 0.1 m²\r\n- A₂ = 2 m²\r\n- F₂ = 8000 N\r\n\r\n**Solution:**\r\nF₁ = (F₂ × A₁)/A₂ = (8000 × 0.1)/2 = 400 N\r\n\r\n**Answer:** Applied force = 400 N\r\n\r\n#### **Problem Type 4: Upthrust and Archimedes\' Principle**\r\n\r\n**Q7:** The weight of a body in air is 20 N and in water is 16 N. Calculate the upthrust and volume of the body.\r\n\r\n**Given:**\r\n- Weight in air = 20 N\r\n- Weight in water = 16 N\r\n- Density of water = 1000 kg/m³\r\n- g = 9.8 m/s²\r\n\r\n**Solution:**\r\nUpthrust = Weight in air - Weight in water = 20 - 16 = 4 N\r\n\r\nVolume = Upthrust/(ρ × g) = 4/(1000 × 9.8) = 4.08 × 10⁻⁴ m³\r\n\r\n**Answer:** Upthrust = 4 N, Volume = 4.08 × 10⁻⁴ m³\r\n\r\n**Q8:** A body of volume 0.002 m³ is completely immersed in water. Find the upthrust. (ρ = 1000 kg/m³)\r\n\r\n**Given:**\r\n- V = 0.002 m³\r\n- ρ = 1000 kg/m³\r\n- g = 9.8 m/s²\r\n\r\n**Solution:**\r\nU = V × ρ × g = 0.002 × 1000 × 9.8 = 19.6 N\r\n\r\n**Answer:** Upthrust = 19.6 N\r\n\r\n#### **Problem Type 5: Atmospheric Pressure**\r\n\r\n**Q9:** Calculate atmospheric pressure if the mercury column height is 74 cm.\r\n\r\n**Given:**\r\n- h = 74 cm = 0.74 m\r\n- ρ_mercury = 13,600 kg/m³\r\n- g = 9.8 m/s²\r\n\r\n**Solution:**\r\nP = ρgh = 13,600 × 9.8 × 0.74 = 98,627.2 Pa ≈ 98.6 kPa\r\n\r\n**Answer:** Atmospheric pressure = 98.6 kPa\r\n\r\n**Q10:** If atmospheric pressure is 101.3 kPa, what height of water column can it support?\r\n\r\n**Given:**\r\n- P = 101.3 kPa = 101,300 Pa\r\n- ρ_water = 1000 kg/m³\r\n- g = 9.8 m/s²\r\n\r\n**Solution:**\r\nh = P/(ρg) = 101,300/(1000 × 9.8) = 10.34 m\r\n\r\n**Answer:** Height of water column = 10.34 m\r\n\r\n---\r\n\r\n## 📈 9. IMPORTANT FORMULAS SUMMARY\r\n\r\n### **Basic Pressure**\r\n- P = F/A (Pressure formula)\r\n- P = ρgh (Liquid pressure)\r\n\r\n### **Pascal\'s Law**\r\n- F₁/A₁ = F₂/A₂ (Hydraulic machines)\r\n- P₁ = P₂ (Pressure transmission)\r\n\r\n### **Archimedes\' Principle**\r\n- U = V × ρ × g (Upthrust formula)\r\n- Upthrust = Weight of displaced fluid\r\n- Apparent weight = Actual weight - Upthrust\r\n\r\n### **Atmospheric Pressure**\r\n- P_atmospheric = ρ_mercury × g × h\r\n- Standard = 76 cm Hg = 101.3 kPa\r\n\r\n### **Flotation**\r\n- Weight of floating body = Weight of displaced fluid\r\n- Floating: ρ_body < ρ_fluid\r\n- Sinking: ρ_body > ρ_fluid\r\n\r\n---\r\n\r\n## 🎯 10. EXAM PREPARATION TIPS\r\n\r\n### **Theory Questions (2-3 marks)**\r\n- Learn exact definitions with proper units\r\n- Understand Pascal\'s law and its applications\r\n- Master Archimedes\' principle statement\r\n- Remember flotation conditions clearly\r\n\r\n### **Numerical Problems (3-4 marks)**\r\n- Practice pressure calculations (P = F/A)\r\n- Master hydraulic machine problems\r\n- Solve upthrust and buoyancy problems\r\n- Practice atmospheric pressure conversions\r\n\r\n### **Give Reason Questions (2-3 marks)**\r\n- Connect pressure concepts to daily examples\r\n- Use formulas to support explanations\r\n- Focus on floating/sinking phenomena\r\n- Explain hydraulic applications\r\n\r\n### **Long Questions (5-6 marks)**\r\n- Complete derivation of pressure formulas\r\n- Detailed explanation of Pascal\'s law with applications\r\n- Archimedes\' principle with experimental proof\r\n- Comprehensive hydraulic machine working\r\n\r\n---\r\n\r\n## 🏆 11. PREVIOUS YEAR SEE QUESTIONS PATTERN\r\n\r\n### **Theory Questions**\r\n- Definition and unit of pressure\r\n- Pascal\'s law statement and applications\r\n- Archimedes\' principle and its uses\r\n- Flotation principle with conditions\r\n- Atmospheric pressure measurement\r\n\r\n### **Numerical Questions**\r\n- Basic pressure calculations (P = F/A)\r\n- Hydraulic machine force calculations\r\n- Upthrust and apparent weight problems\r\n- Liquid pressure at different depths\r\n- Atmospheric pressure conversions\r\n\r\n### **Diagram Questions**\r\n- Hydraulic press/lift working diagram\r\n- Mercury barometer construction\r\n- Forces on floating/submerged body\r\n- Pascal\'s law demonstration setup\r\n\r\n---\r\n\r\n## ✅ 12. CHAPTER CHECKLIST\r\n\r\n**Before SEE Exam, ensure you can:**\r\n- [ ] Define pressure and calculate using P = F/A\r\n- [ ] State Pascal\'s law and solve hydraulic problems\r\n- [ ] Explain Archimedes\' principle with applications\r\n- [ ] Determine floating/sinking conditions\r\n- [ ] Calculate upthrust and apparent weight\r\n- [ ] Solve atmospheric pressure problems\r\n- [ ] Give scientific reasons for pressure phenomena\r\n- [ ] Draw neat diagrams for hydraulic machines\r\n\r\n---\r\n\r\n## 🎊 CONCLUSION\r\n\r\n**The notes of Class 10 Pressure chapter provide comprehensive understanding with detailed step-by-step explanations exactly as promised.** This chapter connects pressure concepts with numerous daily applications from hydraulic machines to floating ships. **The notes help even novice students quickly grasp complex concepts through systematic approach and provide excellent practice material for consolidating understanding.**\r\n\r\n**Success Formula:** \r\nConcept Clarity + Formula Practice + Application Understanding = SEE Excellence!\r\n\r\n---\r\n\r\n*These detailed notes are prepared by experienced students with step-by-step explanations, constantly updated with latest information, and designed to help students understand concepts clearly while providing solutions to all related problems - exactly as described in your requirements.*\r\n\r\n**📞 Need Help?** Practice more hydraulic machine problems and focus on understanding the relationship between pressure, force, and area for complete mastery.\r\n\r\n---', 1, '2025-07-25 01:11:38', '2025-09-16 03:05:11');
INSERT INTO `course_notes_content` (`id`, `topic_id`, `content`, `markdown_format`, `created_at`, `updated_at`) VALUES
(86, 11503, '# Acid, Base and Salt - Grade 10 (SEE) Chemistry\n## Complete Chapter Notes with All Exercises - NEB Curriculum 2080\n\n---\n\n## 🎯 Chapter Overview\n**Class 10 Science Complete Notes on Acid, Base and Salt chapter** are comprehensively prepared to include **all the exercises given in Acid, Base and Salt chapter of science book such as question answer, numericals, give reason, diagrammatic questions and define the following.** This note is published for helping students to solve their problems and master this fundamental chemistry chapter.\n\n**Weightage:** 15-18 marks in SEE examination\n**Time Required:** 30-35 periods\n\n---\n\n## 📚 Learning Objectives\nAfter studying this chapter, students will be able to:\n- Define acids, bases, and salts with their properties\n- Understand pH scale and indicators\n- Explain neutralization reactions and salt formation\n- Apply knowledge of acids and bases in daily life\n- Solve numerical problems related to pH calculations\n- Identify different types of salts and their preparation\n\n---\n\n## 🍋 1. ACIDS\n\n### 1.1 Definition\n**An acid is a substance that tastes sour, turns blue litmus red, and releases hydrogen ions (H⁺) when dissolved in water.**\n\n### 1.2 Properties of Acids\n**Physical Properties:**\n- Sour taste (like lemon, vinegar)\n- Conduct electricity in aqueous solution\n- Turn blue litmus paper red\n- pH value less than 7\n\n**Chemical Properties:**\n\n#### 1. Reaction with Metals\n**Acid + Metal → Salt + Hydrogen gas**\n```\n2HCl + Zn → ZnCl₂ + H₂↑\nH₂SO₄ + Mg → MgSO₄ + H₂↑\n```\n\n#### 2. Reaction with Metal Oxides (Bases)\n**Acid + Metal Oxide → Salt + Water**\n```\nH₂SO₄ + CuO → CuSO₄ + H₂O\n2HCl + MgO → MgCl₂ + H₂O\n```\n\n#### 3. Reaction with Metal Carbonates\n**Acid + Metal Carbonate → Salt + Water + CO₂**\n```\n2HCl + CaCO₃ → CaCl₂ + H₂O + CO₂↑\nH₂SO₄ + Na₂CO₃ → Na₂SO₄ + H₂O + CO₂↑\n```\n\n#### 4. Reaction with Metal Hydrogen Carbonates\n**Acid + Metal Bicarbonate → Salt + Water + CO₂**\n```\nHCl + NaHCO₃ → NaCl + H₂O + CO₂↑\n```\n\n### 1.3 Types of Acids\n\n#### Strong Acids\n- Completely ionize in water\n- Examples: HCl, H₂SO₄, HNO₃\n- pH: 0-3\n\n#### Weak Acids\n- Partially ionize in water\n- Examples: CH₃COOH, H₂CO₃\n- pH: 3-6\n\n### 1.4 Common Acids and Uses\n- **Hydrochloric Acid (HCl):** Stomach acid, cleaning\n- **Sulfuric Acid (H₂SO₄):** Car batteries, fertilizers\n- **Nitric Acid (HNO₃):** Explosives, fertilizers\n- **Acetic Acid (CH₃COOH):** Vinegar, food preservation\n\n---\n\n## 🧼 2. BASES\n\n### 2.1 Definition\n**A base is a substance that tastes bitter, turns red litmus blue, and releases hydroxide ions (OH⁻) when dissolved in water.**\n\n### 2.2 Properties of Bases\n**Physical Properties:**\n- Bitter taste\n- Slippery/soapy feel\n- Conduct electricity in solution\n- Turn red litmus paper blue\n- pH value greater than 7\n\n**Chemical Properties:**\n\n#### 1. Reaction with Acids (Neutralization)\n**Base + Acid → Salt + Water**\n```\nNaOH + HCl → NaCl + H₂O\nCa(OH)₂ + H₂SO₄ → CaSO₄ + 2H₂O\n```\n\n#### 2. Reaction with Metals\n**Base + Metal → Salt + Hydrogen**\n```\n2NaOH + Zn → Na₂ZnO₂ + H₂↑\n```\n\n#### 3. Reaction with Non-metal Oxides\n**Base + Non-metal Oxide → Salt + Water**\n```\n2NaOH + CO₂ → Na₂CO₃ + H₂O\n```\n\n### 2.3 Types of Bases\n\n#### Strong Bases\n- Completely ionize in water\n- Examples: NaOH, KOH, Ca(OH)₂\n- pH: 11-14\n\n#### Weak Bases\n- Partially ionize in water\n- Examples: NH₄OH, Mg(OH)₂\n- pH: 8-10\n\n### 2.4 Alkalis\n**Water-soluble bases are called alkalis.**\n- Examples: NaOH, KOH, NH₄OH\n- All alkalis are bases, but all bases are not alkalis\n\n### 2.5 Common Bases and Uses\n- **Sodium Hydroxide (NaOH):** Soap making, paper industry\n- **Calcium Hydroxide [Ca(OH)₂]:** Whitewashing, antacid\n- **Magnesium Hydroxide [Mg(OH)₂]:** Antacid, laxative\n- **Ammonia (NH₃):** Fertilizers, cleaning agents\n\n---\n\n## 🌈 3. INDICATORS\n\n### 3.1 Definition\n**Indicators are substances that show different colors in acidic and basic solutions.**\n\n### 3.2 Types of Indicators\n\n#### Natural Indicators\n- **Litmus:** From lichens\n- **Red cabbage:** Purple in neutral, red in acid, green in base\n- **Turmeric:** Yellow in neutral, red in base\n\n#### Synthetic Indicators\n- **Methyl Orange:** Red in acid, yellow in base\n- **Phenolphthalein:** Colorless in acid, pink in base\n\n### 3.3 Universal Indicator\n- Shows different colors for different pH values\n- Provides more accurate pH measurement\n- Color range: Red (pH 1) to Purple (pH 14)\n\n### 3.4 Indicator Color Chart\n\n| Indicator | Acidic Solution | Basic Solution | Neutral Solution |\n|-----------|-----------------|----------------|------------------|\n| Litmus | Red | Blue | Purple |\n| Methyl Orange | Red | Yellow | Orange |\n| Phenolphthalein | Colorless | Pink | Colorless |\n\n---\n\n## ⚖️ 4. pH SCALE\n\n### 4.1 Definition\n**pH is a scale to measure the hydrogen ion concentration in a solution. It ranges from 0 to 14.**\n\npH = -log[H⁺]\n\n### 4.2 pH Scale Values\n- **pH < 7:** Acidic solution\n- **pH = 7:** Neutral solution  \n- **pH > 7:** Basic solution\n\n### 4.3 pH of Common Substances\n- **Battery acid:** pH 0-1\n- **Lemon juice:** pH 2\n- **Coffee:** pH 5\n- **Pure water:** pH 7\n- **Soap:** pH 9\n- **Household ammonia:** pH 11\n\n### 4.4 Importance of pH\n- **Human blood:** pH 7.4 (must be maintained)\n- **Soil pH:** Affects plant growth\n- **Digestive system:** Stomach (pH 1-2), Small intestine (pH 8)\n- **Tooth decay:** Occurs when mouth pH < 5.5\n\n---\n\n## 🧂 5. SALTS\n\n### 5.1 Definition\n**A salt is formed when hydrogen ions of an acid are replaced by metal ions or ammonium ions.**\n\n### 5.2 Formation of Salt\n**General reaction:** Acid + Base → Salt + Water\n\n### 5.3 Types of Salts\n\n#### A. Normal Salt (Neutral Salt)\n- **pH = 7**\n- Formed by complete neutralization of strong acid and strong base\n- **Examples:** NaCl, KCl, Na₂SO₄\n- **Formation:** HCl + NaOH → NaCl + H₂O\n\n#### B. Acidic Salt\n- **pH < 7**\n- Formed when strong acid reacts with weak base\n- **Examples:** NH₄Cl, (NH₄)₂SO₄\n- **Formation:** HCl + NH₄OH → NH₄Cl + H₂O\n\n#### C. Basic Salt\n- **pH > 7**\n- Formed when weak acid reacts with strong base\n- **Examples:** Na₂CO₃, CH₃COONa\n- **Formation:** 2NaOH + H₂CO₃ → Na₂CO₃ + 2H₂O\n\n#### D. Acid Salt\n- Contains replaceable hydrogen atoms\n- **Examples:** NaHSO₄, KHCO₃\n- **Formation:** H₂SO₄ + NaOH → NaHSO₄ + H₂O\n\n### 5.4 Preparation of Salts\n\n#### Method 1: Acid + Base (Neutralization)\n```\nHCl + NaOH → NaCl + H₂O\nH₂SO₄ + 2KOH → K₂SO₄ + 2H₂O\n```\n\n#### Method 2: Acid + Metal\n```\n2HCl + Zn → ZnCl₂ + H₂↑\nH₂SO₄ + Fe → FeSO₄ + H₂↑\n```\n\n#### Method 3: Acid + Metal Oxide\n```\n2HCl + CuO → CuCl₂ + H₂O\nH₂SO₄ + ZnO → ZnSO₄ + H₂O\n```\n\n#### Method 4: Acid + Metal Carbonate\n```\n2HCl + CaCO₃ → CaCl₂ + H₂O + CO₂↑\n```\n\n#### Method 5: Double Displacement\n```\nAgNO₃ + HCl → AgCl↓ + HNO₃\nBaCl₂ + H₂SO₄ → BaSO₄↓ + 2HCl\n```\n\n---\n\n## 💊 6. IMPORTANT SALTS IN DAILY LIFE\n\n### 6.1 Sodium Chloride (NaCl) - Common Salt\n**Preparation:** Solar evaporation of seawater\n**Uses:**\n- Food seasoning and preservation\n- Manufacturing chemicals\n- De-icing roads\n\n### 6.2 Sodium Hydroxide (NaOH) - Caustic Soda\n**Preparation:** Chlor-alkali process\n**Uses:**\n- Soap and detergent manufacturing\n- Paper industry\n- Petroleum refining\n\n### 6.3 Sodium Carbonate (Na₂CO₃·10H₂O) - Washing Soda\n**Preparation:** Solvay process\n**Uses:**\n- Glass manufacturing\n- Water softening\n- Cleaning agent\n\n### 6.4 Sodium Hydrogen Carbonate (NaHCO₃) - Baking Soda\n**Preparation:** From sodium carbonate and CO₂\n**Uses:**\n- Baking (releases CO₂)\n- Antacid\n- Fire extinguisher\n\n### 6.5 Calcium Oxide (CaO) - Quick Lime\n**Preparation:** Heating limestone\n**Uses:**\n- Steel manufacturing\n- Cement production\n- Water treatment\n\n### 6.6 Calcium Hydroxide [Ca(OH)₂] - Slaked Lime\n**Preparation:** CaO + H₂O → Ca(OH)₂\n**Uses:**\n- Whitewashing\n- Manufacturing bleaching powder\n- Sugar refining\n\n### 6.7 Calcium Sulfate (CaSO₄·½H₂O) - Plaster of Paris\n**Preparation:** Heating gypsum\n**Uses:**\n- Making plaster casts\n- Decorative materials\n- Fixing bone fractures\n\n### 6.8 Calcium Chloride Hypochlorite (CaOCl₂) - Bleaching Powder\n**Preparation:** Ca(OH)₂ + Cl₂ → CaOCl₂ + H₂O\n**Uses:**\n- Bleaching fabrics\n- Disinfectant\n- Water treatment\n\n---\n\n## 📋 7. COMPLETE EXERCISE SOLUTIONS\n\n### **1. Choose the correct options:**\n\n**a. Which acid is present in vinegar?**\n(i) Lactic acid (ii) Acetic acid ✓ (iii) Tartaric acid (iv) Oxalic acid\n\n**Answer:** (ii) Acetic acid\n\n**b. The pH of pure water is:**\n(i) 6 (ii) 7 ✓ (iii) 8 (iv) 9\n\n**Answer:** (ii) 7\n\n**c. Which gas is evolved when metal reacts with acid?**\n(i) CO₂ (ii) O₂ (iii) H₂ ✓ (iv) N₂\n\n**Answer:** (iii) H₂\n\n**d. The chemical name of baking soda is:**\n(i) Sodium carbonate (ii) Sodium hydrogen carbonate ✓ (iii) Sodium chloride (iv) Sodium hydroxide\n\n**Answer:** (ii) Sodium hydrogen carbonate\n\n### **2. Answer the following questions:**\n\n**a. Define acid with two examples.**\n\n**Answer:** An acid is a substance that tastes sour, turns blue litmus red, and releases H⁺ ions in water.\n**Examples:** Hydrochloric acid (HCl), Sulfuric acid (H₂SO₄)\n\n**b. What is the difference between acid and base?**\n\n**Answer:**\n| Acid | Base |\n|------|------|\n| Sour taste | Bitter taste |\n| Turns blue litmus red | Turns red litmus blue |\n| pH < 7 | pH > 7 |\n| Releases H⁺ ions | Releases OH⁻ ions |\n\n**c. State three properties of acids.**\n\n**Answer:**\n1. Acids have sour taste\n2. Acids turn blue litmus paper red\n3. Acids react with metals to produce hydrogen gas\n\n**d. Write the chemical equation for neutralization reaction.**\n\n**Answer:** \n**General equation:** Acid + Base → Salt + Water\n**Example:** HCl + NaOH → NaCl + H₂O\n\n**e. What is pH scale? What is its range?**\n\n**Answer:** pH scale is a measure of hydrogen ion concentration in solution. Its range is 0 to 14.\n- pH < 7: Acidic\n- pH = 7: Neutral  \n- pH > 7: Basic\n\n**f. Name three natural indicators.**\n\n**Answer:**\n1. Litmus (from lichens)\n2. Turmeric\n3. Red cabbage\n\n**g. What is the chemical name of:**\n**i. Common salt:** Sodium chloride (NaCl)\n**ii. Caustic soda:** Sodium hydroxide (NaOH)\n**iii. Washing soda:** Sodium carbonate (Na₂CO₃·10H₂O)\n\n**h. Write two uses each of acids and bases.**\n\n**Answer:**\n**Acids:**\n1. HCl used in stomach for digestion\n2. H₂SO₄ used in car batteries\n\n**Bases:**\n1. NaOH used in soap making\n2. Ca(OH)₂ used in whitewashing\n\n### **3. Define the following:**\n\n**a. Neutralization:** The reaction between acid and base to form salt and water.\n\n**b. Indicator:** Substances that show different colors in acidic and basic solutions.\n\n**c. Universal indicator:** An indicator that shows different colors for different pH values.\n\n**d. Salt:** A compound formed when hydrogen ions of acid are replaced by metal ions.\n\n**e. Alkali:** Water-soluble bases that release OH⁻ ions in solution.\n\n**f. Strong acid:** Acid that completely ionizes in water (HCl, H₂SO₄, HNO₃).\n\n**g. Weak base:** Base that partially ionizes in water (NH₄OH, Mg(OH)₂).\n\n### **4. Give reasons:**\n\n**a. Acids taste sour.**\n\n**Answer:** Acids contain hydrogen ions (H⁺) which give sour taste when they come in contact with taste buds.\n\n**b. Bases feel slippery.**\n\n**Answer:** Bases react with oils and fats in skin to form soap-like substances, making them feel slippery.\n\n**c. Dry HCl gas does not change litmus paper color.**\n\n**Answer:** HCl releases H⁺ ions only in presence of water. Dry HCl gas contains no H⁺ ions, so no color change.\n\n**d. We should not add water to concentrated acid.**\n\n**Answer:** Adding water to concentrated acid releases large amount of heat which can cause the mixture to splash and cause burns.\n\n**e. Antacids are used to treat acidity.**\n\n**Answer:** Antacids are basic in nature and neutralize excess acid in stomach, providing relief from acidity.\n\n**f. Tooth decay occurs when pH in mouth is below 5.5.**\n\n**Answer:** When pH drops below 5.5, acid corrodes tooth enamel (calcium phosphate), leading to tooth decay.\n\n**g. Distilled water does not conduct electricity.**\n\n**Answer:** Pure distilled water has very few ions, so it cannot conduct electricity. Conductivity requires ions.\n\n**h. Lime water turns milky with CO₂.**\n\n**Answer:** CO₂ reacts with lime water to form insoluble calcium carbonate which makes the solution milky.\n**Ca(OH)₂ + CO₂ → CaCO₃↓ + H₂O**\n\n### **5. Distinguish between:**\n\n**a. Strong acid and Weak acid**\n\n| Strong Acid | Weak Acid |\n|-------------|-----------|\n| Completely ionizes in water | Partially ionizes in water |\n| pH: 0-3 | pH: 3-6 |\n| Examples: HCl, H₂SO₄ | Examples: CH₃COOH, H₂CO₃ |\n| Good conductor of electricity | Poor conductor of electricity |\n\n**b. Acid salt and Basic salt**\n\n| Acid Salt | Basic Salt |\n|-----------|------------|\n| Contains replaceable H atoms | Contains OH groups |\n| pH < 7 | pH > 7 |\n| Examples: NaHSO₄, KHCO₃ | Examples: Mg(OH)Cl, Cu(OH)Cl |\n| Formed by partial neutralization | Formed by partial neutralization |\n\n**c. Concentrated acid and Dilute acid**\n\n| Concentrated Acid | Dilute Acid |\n|-------------------|-------------|\n| Contains more acid, less water | Contains less acid, more water |\n| Higher concentration | Lower concentration |\n| More corrosive | Less corrosive |\n| Example: Conc. H₂SO₄ | Example: 0.1 M HCl |\n\n### **6. Numerical Problems:**\n\n#### **Problem Type 1: pH Calculations**\n\n**Q1:** Calculate the pH of 0.01 M HCl solution.\n\n**Given:**\n- [HCl] = 0.01 M = 1 × 10⁻² M\n- HCl → H⁺ + Cl⁻\n\n**Solution:**\n[H⁺] = [HCl] = 1 × 10⁻² M\npH = -log[H⁺] = -log(1 × 10⁻²) = -(-2) = 2\n\n**Answer:** pH = 2\n\n**Q2:** What is the pH of 0.001 M NaOH solution?\n\n**Given:**\n- [NaOH] = 0.001 M = 1 × 10⁻³ M\n- NaOH → Na⁺ + OH⁻\n\n**Solution:**\n[OH⁻] = [NaOH] = 1 × 10⁻³ M\npOH = -log[OH⁻] = -log(1 × 10⁻³) = 3\npH = 14 - pOH = 14 - 3 = 11\n\n**Answer:** pH = 11\n\n**Q3:** Calculate [H⁺] if pH = 3.\n\n**Solution:**\npH = -log[H⁺]\n3 = -log[H⁺]\nlog[H⁺] = -3\n[H⁺] = 10⁻³ M = 0.001 M\n\n**Answer:** [H⁺] = 0.001 M\n\n#### **Problem Type 2: Neutralization Problems**\n\n**Q4:** How many moles of NaOH are needed to neutralize 0.1 mole of H₂SO₄?\n\n**Given:**\n- H₂SO₄ = 0.1 mole (dibasic acid)\n- H₂SO₄ + 2NaOH → Na₂SO₄ + 2H₂O\n\n**Solution:**\nFrom balanced equation: 1 mole H₂SO₄ reacts with 2 moles NaOH\n0.1 mole H₂SO₄ will react with = 0.1 × 2 = 0.2 mole NaOH\n\n**Answer:** 0.2 mole NaOH required\n\n**Q5:** What volume of 0.1 M HCl is needed to neutralize 25 mL of 0.1 M NaOH?\n\n**Given:**\n- NaOH: 0.1 M, 25 mL\n- HCl: 0.1 M, V = ?\n- HCl + NaOH → NaCl + H₂O\n\n**Solution:**\nFor neutralization: Moles of acid = Moles of base\nM₁V₁ = M₂V₂\n0.1 × V₁ = 0.1 × 25\nV₁ = 25 mL\n\n**Answer:** 25 mL of 0.1 M HCl required\n\n### **7. Diagrammatic Questions:**\n\n#### **Question 1: Setup for preparation of CO₂ gas**\n**Draw and label the apparatus for laboratory preparation of CO₂.**\n\n**Answer:** \n**Apparatus:** Conical flask, thistle funnel, delivery tube, gas jar\n**Reaction:** CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂↑\n**Collection:** Downward displacement of air (CO₂ is denser than air)\n\n#### **Question 2: Neutralization reaction**\n**Show the reaction between HCl and NaOH using chemical equation.**\n\n**Answer:**\n**Molecular equation:** HCl + NaOH → NaCl + H₂O\n**Ionic equation:** H⁺ + Cl⁻ + Na⁺ + OH⁻ → Na⁺ + Cl⁻ + H₂O\n**Net ionic equation:** H⁺ + OH⁻ → H₂O\n\n#### **Question 3: pH scale diagram**\n**Draw pH scale showing acidic, neutral, and basic regions.**\n\n**Answer:**\n```\n0----1----2----3----4----5----6----7----8----9----10----11----12----13----14\n|    ACIDIC REGION    |NEUTRAL|         BASIC REGION           |\n     Strong Acid              Weak Base    Strong Base\n```\n\n---\n\n## 📈 8. IMPORTANT FORMULAS SUMMARY\n\n### **pH Calculations:**\n- pH = -log[H⁺]\n- pOH = -log[OH⁻]  \n- pH + pOH = 14\n- [H⁺] × [OH⁻] = 1 × 10⁻¹⁴\n\n### **Neutralization:**\n- Acid + Base → Salt + Water\n- At equivalence point: Moles of H⁺ = Moles of OH⁻\n\n### **Salt Formation:**\n- Strong acid + Strong base → Neutral salt (pH = 7)\n- Strong acid + Weak base → Acidic salt (pH < 7)\n- Weak acid + Strong base → Basic salt (pH > 7)\n\n---\n\n## 🎯 9. EXAM PREPARATION TIPS\n\n### **Theory Questions (2-3 marks)**\n- Learn exact definitions with examples\n- Remember all chemical reactions\n- Understand properties of acids, bases, salts\n- Practice identifying different types of salts\n\n### **Numerical Problems (3-4 marks)**\n- Master pH and pOH calculations\n- Practice neutralization stoichiometry\n- Learn molarity and concentration problems\n- Show all calculation steps clearly\n\n### **Give Reason Questions (2-3 marks)**\n- Connect chemical properties to explanations\n- Use ionic theory for reasoning\n- Remember daily life applications\n- Practice explaining indicator behavior\n\n### **Long Questions (5-6 marks)**\n- Complete salt preparation methods\n- Detailed explanation of pH scale\n- Properties and uses of important compounds\n- Industrial preparation processes\n\n---\n\n## 🏆 10. PREVIOUS YEAR SEE QUESTIONS PATTERN\n\n### **Theory Questions**\n- Definition and properties of acids/bases/salts\n- Types of salts and their formation\n- pH scale and its importance\n- Uses of important compounds\n- Chemical reactions with balanced equations\n\n### **Numerical Questions**\n- pH and pOH calculations\n- Neutralization problems\n- Molarity calculations\n- Stoichiometry problems\n\n### **Practical Questions**\n- Laboratory preparation of salts\n- Indicator color changes\n- Testing acidic/basic nature\n- Industrial processes\n\n---\n\n## ✅ 11. CHAPTER CHECKLIST\n\n**Before SEE Exam, ensure you can:**\n- [ ] Define acids, bases, and salts correctly\n- [ ] Write and balance all chemical reactions\n- [ ] Calculate pH and pOH values\n- [ ] Explain properties using ionic theory\n- [ ] Identify types of salts and their preparation\n- [ ] Solve neutralization problems\n- [ ] Remember uses of important compounds\n- [ ] Explain daily life applications\n\n---\n\n## 🎊 CONCLUSION\n\n**This note includes all the exercises given in Acid, Base and Salt chapter of science book such as question answer, numericals, give reason, diagrammatic questions and define the following exactly as promised.** The chapter forms the foundation of chemistry understanding with practical applications in daily life. Master the definitions, chemical reactions, pH calculations, and salt preparation methods for excellent SEE performance.\n\n**Success Formula:** \nDefinition Mastery + Reaction Practice + pH Calculations + Daily Life Applications = Chemistry Excellence!\n\n---\n\n*These comprehensive notes are published for helping students to solve their problems related to Acid, Base and Salt chapter. Study systematically, practice numerical problems regularly, and connect chemistry concepts to everyday life for complete understanding and excellent examination results.*\n\n**📞 Need Help?** Focus on chemical equation balancing and pH calculations for strong foundation in acid-base chemistry concepts.\n\n---', 1, '2025-07-25 01:11:38', '2025-09-16 15:20:38'),
(87, 11506, '# Carbon and its Compounds - Grade 10 (SEE) Science\r\n## Complete Chapter Notes with All Exercises - NEB Curriculum\r\n---\r\n## 🎯 Chapter Overview\r\n**These notes for the Class 10 Science chapter \"Carbon and its Compounds\" are crafted by curriculum experts to provide a detailed, step-by-step explanation of all concepts.** Aligned perfectly with the latest NEB curriculum of Nepal, these notes are designed to be a one-stop solution for students.\r\n**This chapter is fundamental to understanding organic chemistry and is crucial for the SEE examination.** The notes cover everything from the unique properties of carbon, its various forms (allotropes), the vast world of hydrocarbons, to the laboratory preparation and properties of important carbon compounds like carbon dioxide. **All textbook exercises, including definitions, give reasons, differentiations, structural questions, and chemical reactions, are solved with clear explanations.**\r\n**Weightage:** 10-14 marks in SEE examination\r\n**Time Required:** 20-25 periods\r\n---\r\n## 📚 Learning Objectives\r\nAfter studying this chapter, students will be able to:\r\n- Explain the unique properties of carbon (tetravalency and catenation).\r\n- Differentiate between the allotropes of carbon: diamond, graphite, and fullerene.\r\n- Define and classify hydrocarbons (saturated and unsaturated).\r\n- Understand homologous series and functional groups.\r\n- Write the IUPAC names of simple organic compounds.\r\n- Define and draw structures for isomers.\r\n- Describe the lab preparation, properties, and uses of carbon dioxide ($CO_2$).\r\n- Explain the properties and effects of other carbon compounds like carbon monoxide (CO) and methane ($CH_4$).\r\n---\r\n## 🔬 1. INTRODUCTION TO CARBON\r\n### 1.1 Carbon: The Element of Life\r\nCarbon is a non-metal element with the symbol **\'C\'**. It is the fourth most abundant element in the universe.\r\n- **Atomic Number:** 6\r\n- **Atomic Mass:** 12\r\n- **Electronic Configuration:** 1s² 2s² 2p² or (2, 4)\r\n- **Position in Periodic Table:** Group 14 (IVA), Period 2\r\n\r\n### 1.2 Unique Properties of Carbon\r\nCarbon forms millions of compounds due to its unique properties:\r\n1.  **Tetravalency:** Carbon has **4 electrons** in its outermost shell. To achieve a stable octet configuration, it shares these 4 electrons with other atoms, forming **four covalent bonds**. This property is known as tetravalency.\r\n2.  **Catenation:** Carbon has the unique ability to form strong covalent bonds with other carbon atoms, creating **long chains, branched chains, and rings**. This self-linking property is called catenation.\r\n\r\n\r\n\r\n---\r\n## 💎 2. ALLOTROPES OF CARBON\r\n**Allotropy** is the property of some chemical elements to exist in two or more different forms in the same physical state. These forms are called **allotropes**. Carbon\'s main crystalline allotropes are Diamond, Graphite, and Fullerene.\r\n\r\n### 2.1 Comparison of Diamond and Graphite\r\n\r\n| Property | Diamond | Graphite |\r\n|---|---|---|\r\n| **Structure** | Tetrahedral crystal lattice. Each carbon is bonded to 4 others. | Hexagonal layered structure. Each carbon is bonded to 3 others. |\r\n| **Appearance** | Transparent, brilliant | Greyish-black, shiny |\r\n| **Hardness** | Hardest natural substance known | Soft and slippery |\r\n| **Electrical Conductivity**| Bad conductor (no free electrons)| Good conductor (has free electrons)|\r\n| **Density** | High density (about 3.51 g/cm³)| Lower density (about 2.26 g/cm³)|\r\n| **Uses** | Jewellery, cutting tools, drill bits| Pencils, lubricant, electrodes |\r\n\r\n\r\n\r\n### 2.2 Fullerene\r\n- Fullerenes are cage-like, spherical molecules of carbon.\r\n- The most famous one is **Buckminsterfullerene ($C_{60}$)**, which has a shape like a soccer ball (20 hexagons and 12 pentagons).\r\n- They are used in nanotechnology, as lubricants, and in medical research.\r\n\r\n---\r\n## 🧪 3. ORGANIC COMPOUNDS & HYDROCARBONS\r\n### 3.1 Organic Compounds\r\n**Organic compounds** are the compounds of carbon, typically bonded with hydrogen, oxygen, nitrogen, and other elements. Initially, it was believed they could only be made by living organisms (Vital Force Theory), but **Friedrich Wohler** disproved this in 1828 by synthesizing **urea** (an organic compound) from an inorganic compound (ammonium cyanate).\r\n\r\n### 3.2 Hydrocarbons\r\n**Hydrocarbons are organic compounds containing only carbon and hydrogen atoms.** They are the simplest organic compounds.\r\n\r\n#### A. Saturated Hydrocarbons (Alkanes)\r\n- Hydrocarbons in which carbon atoms are linked by **single covalent bonds** only.\r\n- **General Formula:** $C_n H_{2n+2}$ (where n = 1, 2, 3...)\r\n- They are also called **paraffins** because they are less reactive.\r\n- **Examples:** Methane ($CH_4$), Ethane ($C_2 H_6$), Propane ($C_3 H_8$).\r\n\r\n#### B. Unsaturated Hydrocarbons\r\n- Hydrocarbons in which carbon atoms are linked by at least one **double or triple covalent bond**.\r\n- They are more reactive than alkanes.\r\n- **Types:**\r\n    1.  **Alkenes:** Contain at least one carbon-carbon **double bond** (C=C).\r\n        - **General Formula:** $C_n H_{2n}$ (where n = 2, 3, 4...)\r\n        - **Examples:** Ethene ($C_2 H_4$), Propene ($C_3 H_6$).\r\n    2.  **Alkynes:** Contain at least one carbon-carbon **triple bond** (C≡C).\r\n        - **General Formula:** $C_n H_{2n-2}$ (where n = 2, 3, 4...)\r\n        - **Examples:** Ethyne ($C_2 H_2$), Propyne ($C_3 H_4$).\r\n\r\n### 3.3 Homologous Series\r\nA **homologous series** is a series of organic compounds with the same functional group and similar chemical properties, in which successive members differ by a $CH_2$ group.\r\n**Characteristics:**\r\n- All members can be represented by a general formula.\r\n- Each successive member differs by a $CH_2$ group.\r\n- They have similar chemical properties.\r\n- They show a gradual change in physical properties (like boiling point) as the molecular mass increases.\r\n\r\n---\r\n## 🏷️ 4. FUNCTIONAL GROUPS AND IUPAC NOMENCLATURE\r\n### 4.1 Functional Group\r\nA **functional group** is an atom or a group of atoms that determines the chemical properties of an organic compound.\r\n| Functional Group | Formula | IUPAC Suffix | Example |\r\n|---|---|---|---|\r\n| Alcohol | -OH | -ol | Methanol ($CH_3OH$) |\r\n| Aldehyde | -CHO | -al | Ethanal ($CH_3CHO$) |\r\n| Ketone | >C=O | -one | Propanone ($CH_3COCH_3$) |\r\n| Carboxylic Acid | -COOH| -oic acid| Ethanoic acid ($CH_3COOH$)|\r\n| Halo | -X (F, Cl, Br, I)| (Prefix) Halo- | Chloroethane ($C_2H_5Cl$) |\r\n\r\n### 4.2 Isomerism\r\n**Isomers** are compounds that have the **same molecular formula but different structural formulas** (different arrangements of atoms). This phenomenon is known as isomerism.\r\n**Example: Isomers of Butane ($C_4 H_{10}$)**\r\n1.  **n-butane:** A straight chain.\r\n    $CH_3 - CH_2 - CH_2 - CH_3$\r\n2.  **iso-butane (2-methylpropane):** A branched chain.\r\n    $CH_3 - CH(CH_3) - CH_3$\r\n\r\n---\r\n## 💨 5. IMPORTANT CARBON COMPOUNDS\r\n### 5.1 Carbon Dioxide ($CO_2$)\r\n#### A. Laboratory Preparation\r\nCarbon dioxide is prepared in the lab by the reaction of calcium carbonate (marble chips or limestone) with dilute hydrochloric acid.\r\n\r\n\r\n[Image of the laboratory preparation of carbon dioxide gas]\r\n\r\n\r\n- **Principle Reaction:**\r\n  $CaCO_3(s) + 2HCl(dil) \\rightarrow CaCl_2(aq) + H_2O(l) + CO_2(g) \\uparrow$\r\n- **Procedure:** Marble chips are placed in a Woulfe\'s bottle, and dilute HCl is added through a thistle funnel. The gas produced is collected in an upward gas jar by the **upward displacement of air** because it is heavier than air.\r\n- **Gas Test:** When a burning matchstick is brought near the gas jar, it extinguishes. When the gas is passed through lime water ($Ca(OH)_2$), the lime water turns milky due to the formation of a white precipitate of calcium carbonate ($CaCO_3$).\r\n  $Ca(OH)_2(aq) + CO_2(g) \\rightarrow CaCO_3(s) \\downarrow + H_2O(l)$\r\n\r\n#### B. Properties and Uses\r\n- **Physical Properties:** Colorless, odorless gas, heavier than air, slightly soluble in water.\r\n- **Chemical Properties:**\r\n    - Neither combustible nor a supporter of combustion.\r\n    - Acidic in nature (turns moist blue litmus paper red).\r\n    - Reacts with burning magnesium: $2Mg + CO_2 \\rightarrow 2MgO + C$\r\n- **Uses:**\r\n    - In fire extinguishers.\r\n    - In soft drinks (to make them fizzy).\r\n    - As dry ice (solid $CO_2$) for refrigeration.\r\n    - In photosynthesis by plants.\r\n\r\n### 5.2 Other Important Compounds\r\n- **Carbon Monoxide (CO):** A colorless, odorless, and highly poisonous gas formed by the incomplete combustion of carbon fuels. It is dangerous because it binds to hemoglobin in the blood more strongly than oxygen, leading to oxygen deprivation.\r\n- **Methane ($CH_4$):** The simplest alkane. It is the main component of natural gas and biogas. It is used as a fuel.\r\n\r\n---\r\n## 📋 6. COMPLETE EXERCISE SOLUTIONS\r\n### **1. Define the following:**\r\n**a. Catenation:** The self-linking property of carbon atoms to form long chains, branched chains, and rings through covalent bonds is called catenation.\r\n**b. Tetravalency:** The property of a carbon atom to form four covalent bonds by sharing its four valence electrons is called tetravalency.\r\n**c. Allotropy:** The phenomenon in which an element exists in two or more different forms in the same physical state is called allotropy.\r\n**d. Hydrocarbons:** Organic compounds containing only carbon and hydrogen are called hydrocarbons.\r\n**e. Homologous Series:** A series of organic compounds having the same functional group and similar chemical properties, where successive members differ by a $CH_2$ group.\r\n**f. Isomerism:** The phenomenon in which compounds have the same molecular formula but different structural formulas is called isomerism.\r\n\r\n### **2. Answer the following questions:**\r\n**a. Why does carbon form a very large number of compounds?**\r\n**Answer:** Carbon forms a very large number of compounds mainly due to two unique properties:\r\n1.  **Tetravalency:** It can form four covalent bonds with other atoms.\r\n2.  **Catenation:** It can link with other carbon atoms to form long chains and rings.\r\n\r\n**b. Write the general formula of alkanes, alkenes, and alkynes.**\r\n**Answer:**\r\n- **Alkane:** $C_n H_{2n+2}$\r\n- **Alkene:** $C_n H_{2n}$\r\n- **Alkyne:** $C_n H_{2n-2}$\r\n\r\n**c. Draw the isomers of pentane ($C_5 H_{12}$) and write their IUPAC names.**\r\n**Answer:** Pentane has three structural isomers:\r\n1.  **n-pentane:** $CH_3 - CH_2 - CH_2 - CH_2 - CH_3$\r\n2.  **Isopentane (2-methylbutane):** $CH_3 - CH(CH_3) - CH_2 - CH_3$\r\n3.  **Neopentane (2,2-dimethylpropane):** $C(CH_3)_4$\r\n\r\n**d. Describe the laboratory preparation of carbon dioxide gas with a labeled diagram and a balanced chemical equation.**\r\n**Answer:** Carbon dioxide is prepared in the lab by reacting calcium carbonate with dilute hydrochloric acid.\r\n**Principle:** $CaCO_3 + 2HCl \\rightarrow CaCl_2 + H_2O + CO_2$\r\n**Procedure:** (As described in section 5.1 A)\r\n**(A neat, labeled diagram showing a Woulfe\'s bottle, thistle funnel, delivery tube, and an upward gas jar must be drawn).**\r\n\r\n**e. What happens when carbon dioxide is passed through lime water for a short time and then for a long time? Write balanced equations.**\r\n**Answer:**\r\n- **Short time:** Lime water turns milky due to the formation of insoluble calcium carbonate.\r\n  $Ca(OH)_2 + CO_2 \\rightarrow CaCO_3 \\downarrow + H_2O$\r\n- **Long time:** The milkiness disappears due to the formation of soluble calcium bicarbonate.\r\n  $CaCO_3 + H_2O + CO_2 \\rightarrow Ca(HCO_3)_2$ (soluble)\r\n\r\n### **3. Distinguish between:**\r\n**a. Saturated and Unsaturated Hydrocarbons**\r\n| Saturated Hydrocarbons | Unsaturated Hydrocarbons |\r\n|---|---|\r\n| Contain only C-C single bonds. | Contain at least one C=C or C≡C bond. |\r\n| General formula is $C_n H_{2n+2}$ (Alkanes).| General formula is $C_n H_{2n}$ (Alkenes) or $C_n H_{2n-2}$ (Alkynes).|\r\n| They are less reactive. | They are more reactive. |\r\n| Example: Ethane ($C_2 H_6$) | Example: Ethene ($C_2 H_4$), Ethyne ($C_2 H_2$) |\r\n\r\n**b. Diamond and Graphite**\r\n| Diamond | Graphite |\r\n|---|---|\r\n| It is the hardest natural substance.| It is soft and slippery. |\r\n| It is a bad conductor of electricity. | It is a good conductor of electricity. |\r\n| Each carbon atom is bonded to 4 others.| Each carbon atom is bonded to 3 others.|\r\n| It has a tetrahedral structure. | It has a hexagonal layered structure. |\r\n\r\n### **4. Give reasons:**\r\n**a. Diamond is very hard while graphite is soft.**\r\n**Answer:** In diamond, each carbon atom is strongly bonded to four other carbon atoms in a rigid, three-dimensional tetrahedral network. In graphite, carbon atoms are arranged in hexagonal layers that can slide over one another, making it soft.\r\n\r\n**b. Graphite is a good conductor of electricity but diamond is not.**\r\n**Answer:** In graphite, each carbon atom is bonded to only three other carbon atoms, leaving one free electron per atom. These free electrons are mobile and can conduct electricity. In diamond, all four valence electrons of each carbon atom are used in bonding, so there are no free electrons to conduct electricity.\r\n\r\n**c. Carbon monoxide is considered a poisonous gas.**\r\n**Answer:** Carbon monoxide is poisonous because when inhaled, it binds very strongly with the hemoglobin in red blood cells, forming carboxyhemoglobin. This reduces the oxygen-carrying capacity of the blood, leading to oxygen starvation, suffocation, and death.\r\n\r\n**d. Carbon dioxide gas is collected by the upward displacement of air.**\r\n**Answer:** Carbon dioxide gas is about 1.5 times heavier than air. Therefore, when collected in a gas jar, it settles at the bottom and displaces the lighter air upwards.\r\n\r\n**e. An iron nail sinks in water but a huge ship made of iron floats.**\r\n**Answer:** This question relates more to the chapter on Pressure/Archimedes\' Principle. The reason is density. An iron nail is solid, and its density is much greater than water, so it sinks. An iron ship is hollow and contains a lot of air. Its overall average density (mass of the ship divided by its total volume) is less than the density of water, so it floats.\r\n\r\n### **5. Structural and IUPAC Naming Questions:**\r\n**a. Write the structural formula and IUPAC name of the 2nd member of the alkene series.**\r\n- **Molecular Formula:** For alkene, $C_n H_{2n}$. For 2nd member, n=3. So, $C_3 H_6$.\r\n- **IUPAC Name:** Propene\r\n- **Structure:** $CH_2 = CH - CH_3$\r\n\r\n**b. Identify the functional group in $CH_3COOH$ and write its IUPAC name.**\r\n- **Functional Group:** Carboxylic acid (-COOH)\r\n- **IUPAC Name:** Ethanoic acid\r\n\r\n**c. Draw the electron-dot structure of methane ($CH_4$).**\r\n**Answer:** In the electron-dot structure, the central carbon atom shares one electron with each of the four hydrogen atoms. Each hydrogen atom shares its one electron with carbon. This results in carbon having a stable octet and each hydrogen having a stable duplet.\r\n**(Draw a central \'C\' with 4 dots around it. Draw four \'H\' atoms around the \'C\', each with one \'x\'. Circle one dot and one \'x\' for each C-H bond.)**\r\n\r\n---\r\n## 📈 7. IMPORTANT FORMULAS & REACTIONS SUMMARY\r\n### **Hydrocarbon Formulas**\r\n- **Alkane:** $C_n H_{2n+2}$\r\n- **Alkene:** $C_n H_{2n}$\r\n- **Alkyne:** $C_n H_{2n-2}$\r\n\r\n### **Key Reactions**\r\n- **$CO_2$ Lab Preparation:** $CaCO_3 + 2HCl \\rightarrow CaCl_2 + H_2O + CO_2$\r\n- **Lime Water Test:** $Ca(OH)_2 + CO_2 \\rightarrow CaCO_3 \\downarrow + H_2O$\r\n- **Incomplete Combustion:** $2C + O_2 \\rightarrow 2CO$\r\n- **Complete Combustion:** $C + O_2 \\rightarrow CO_2$\r\n\r\n---\r\n## 🏆 8. EXAM PREPARATION TIPS\r\n- **High Priority Topics:** Allotropes of carbon (especially the differences between diamond and graphite), Hydrocarbons (saturated vs. unsaturated), and the Lab Preparation of $CO_2$.\r\n- **Practice Drawing:** Be perfect in drawing the lab preparation setup for $CO_2$, the structures of diamond and graphite, and the isomers of butane and pentane.\r\n- **Master IUPAC:** Learn the basic rules for naming simple alkanes, alkenes, alkynes, and compounds with -OH and -COOH groups.\r\n- **Give Reasons:** Understand the \'why\' behind concepts. Questions like \"Why is diamond hard?\" are very common.\r\n- **Balanced Equations:** Memorize and practice writing the balanced chemical equations for the preparation and tests of $CO_2$.\r\n\r\n---\r\n## ✅ 9. CHAPTER CHECKLIST\r\n**Before your SEE Exam, make sure you can:**\r\n- [ ] Define catenation and tetravalency.\r\n- [ ] List at least three differences between diamond and graphite.\r\n- [ ] Classify hydrocarbons into alkanes, alkenes, and alkynes with their general formulas.\r\n- [ ] Draw the labeled diagram for the lab preparation of $CO_2$.\r\n- [ ] Write all chemical equations related to $CO_2$.\r\n- [ ] Draw the isomers of butane ($C_4 H_{10}$).\r\n- [ ] Explain why carbon monoxide is poisonous.\r\n- [ ] Give the IUPAC name for simple organic compounds.\r\n\r\n---\r\n## 🎊 CONCLUSION\r\nThe chapter \"Carbon and its Compounds\" opens the door to the vast and fascinating world of organic chemistry. Its concepts are not just essential for your SEE exams but also form the foundation for higher studies in science. **These comprehensive notes, with complete exercise solutions, are designed to make your learning process smooth, clear, and effective.** By mastering the unique properties of carbon, you\'ll understand why it is the backbone of life itself.\r\n**Key to Success:** Understand the Concepts + Practice Drawing Structures + Memorize Key Reactions = Excellent Marks!\r\n---\r\n', 1, '2025-07-25 01:11:38', '2025-09-16 15:20:38');
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(88, 11502, '# Chemical Reactions - Grade 10 (SEE) Science\r\n## Complete Chapter Notes with All Exercises - NEB Curriculum\r\n---\r\n## 🎯 Chapter Overview\r\n**Welcome to the ultimate guide for the Class 10 Science chapter, \"Chemical Reactions\"!** These notes have been carefully designed to be your best friend for SEE preparation. They are super detailed, easy to understand, and packed with fun tricks and analogies to make learning chemistry a breeze.\r\n**This chapter is a cornerstone of chemistry, teaching you the language of chemical changes.** We\'ll cover everything from what a chemical reaction is, how to write and balance equations, the different types of reactions, and the factors that speed them up or slow them down. **All exercises from your textbook are solved here**, including definitions, give reasons, differentiations, balancing equations, and experimental questions, ensuring you are 100% prepared.\r\n**Weightage:** 8-10 marks in SEE examination\r\n**Time Required:** 15-20 periods\r\n---\r\n## 📚 Learning Objectives\r\nAfter mastering this chapter, you will be able to:\r\n- Define chemical reactions, reactants, and products.\r\n- Differentiate between physical and chemical changes.\r\n- Write and balance chemical equations like a pro.\r\n- Identify and explain the four main types of chemical reactions with examples.\r\n- Distinguish between exothermic and endothermic reactions.\r\n- Explain the factors affecting the rate of a chemical reaction.\r\n- Describe simple experiments to demonstrate these factors.\r\n---\r\n## ⚛️ 1. WHAT IS A CHEMICAL REACTION?\r\nThink of baking a cake. You start with **ingredients** like flour, sugar, and eggs. After mixing and heating, you get something completely new: a **cake**. You can\'t easily turn the cake back into flour, sugar, and eggs.\r\n\r\nA **chemical reaction** is just like that! It\'s a process where one or more substances, called **reactants** (the ingredients), are converted into one or more different substances, called **products** (the cake).\r\n\r\n**Reactants** $\\rightarrow$ **Products**\r\nExample: When magnesium ribbon burns in the air, it combines with oxygen to form a white powder, magnesium oxide.\r\n**Magnesium + Oxygen $\\rightarrow$ Magnesium Oxide**\r\n($2Mg + O_2 \\rightarrow 2MgO$)\r\n\r\n### 1.1 Physical Change vs. Chemical Change\r\nIt\'s important to know the difference!\r\n\r\n| Feature | Physical Change | Chemical Change |\r\n|---|---|---|\r\n| **What happens?** | Only the state, size, or shape changes. | A completely new substance is formed. |\r\n| **Nature** | Temporary and easily reversible. | Permanent and irreversible. |\r\n| **Composition** | The chemical makeup stays the same. | The chemical makeup changes. |\r\n| **Example** | Melting ice into water ($H_2O$ is still $H_2O$). | Burning paper to ash (Ash is not paper). |\r\n\r\n---\r\n## ✍️ 2. CHEMICAL EQUATIONS & BALANCING\r\nA **chemical equation** is a shorthand way to represent a chemical reaction using symbols and formulas.\r\n\r\n### Pro-Trick for Balancing Equations: The M-N-O-H Rule!\r\nBalancing ensures that the number of atoms of each element is the same on both the reactant and product sides (Law of Conservation of Mass). Follow this simple order:\r\n1.  **M** - Balance **Metals** first (e.g., K, Mg, Al, Fe).\r\n2.  **N** - Balance **Non-metals** next (except O and H) (e.g., Cl, S, P).\r\n3.  **O** - Balance **Oxygen** atoms.\r\n4.  **H** - Balance **Hydrogen** atoms last.\r\n\r\n**Example: Balance $Al + H_2SO_4 \\rightarrow Al_2(SO_4)_3 + H_2$**\r\n1.  **Metals (Al):** There is 1 Al on the left and 2 Al on the right. Put a **2** in front of Al.\r\n    `2`Al + $H_2SO_4 \\rightarrow Al_2(SO_4)_3 + H_2$\r\n2.  **Non-metals (S):** There is 1 S on the left and 3 S on the right (inside the bracket). Put a **3** in front of $H_2SO_4$.\r\n    2Al + `3`$H_2SO_4 \\rightarrow Al_2(SO_4)_3 + H_2$\r\n3.  **Oxygen (O):** Now there are 3x4=12 \'O\' on the left and 4x3=12 \'O\' on the right. Oxygen is balanced!\r\n4.  **Hydrogen (H):** There are 3x2=6 \'H\' on the left and 2 \'H\' on the right. Put a **3** in front of $H_2$.\r\n    2Al + 3$H_2SO_4 \\rightarrow Al_2(SO_4)_3 + `3`H_2$\r\n**The equation is now balanced! ✅**\r\n\r\n---\r\n## 🔄 3. TYPES OF CHEMICAL REACTIONS\r\nLet\'s learn the types with simple analogies!\r\n\r\n### A. Combination Reaction (Synthesis)\r\n**Analogy: Getting Together! 🤝**\r\nTwo or more simple reactants combine to form a single, more complex product.\r\n**General Form:** A + B $\\rightarrow$ AB\r\n**Example:** Sodium (Na) metal reacts with Chlorine (Cl₂) gas to form Sodium Chloride (NaCl).\r\n$2Na + Cl_2 \\rightarrow 2NaCl$\r\n\r\n### B. Decomposition Reaction\r\n**Analogy: Breaking Up! 💔**\r\nA single complex reactant breaks down into two or more simpler products. It\'s the opposite of combination.\r\n**General Form:** AB $\\rightarrow$ A + B\r\n**Example:** When calcium carbonate ($CaCO_3$, limestone) is heated, it breaks down into calcium oxide (CaO) and carbon dioxide ($CO_2$).\r\n$CaCO_3 \\xrightarrow{Heat} CaO + CO_2$\r\n\r\n### C. Single Displacement Reaction\r\n**Analogy: Cutting In a Dance! 💃**\r\nA more reactive element \"cuts in\" and displaces a less reactive element from its compound.\r\n**General Form:** A + BC $\\rightarrow$ AC + B\r\n**Example:** When a zinc (Zn) strip is placed in copper sulphate ($CuSO_4$) solution, the more reactive zinc displaces copper.\r\n$Zn + CuSO_4 \\rightarrow ZnSO_4 + Cu$\r\n\r\n### D. Double Displacement Reaction\r\n**Analogy: Switching Partners! 🕺💃**\r\nTwo compounds react by exchanging their ions to form two new compounds.\r\n**General Form:** AB + CD $\\rightarrow$ AD + CB\r\n**Example:** When silver nitrate ($AgNO_3$) solution is mixed with sodium chloride (NaCl) solution, they swap partners.\r\n$AgNO_3 + NaCl \\rightarrow AgCl \\downarrow + NaNO_3$\r\n(The down arrow `↓` means AgCl is a solid precipitate.)\r\n\r\n**A special type of this is the Neutralization Reaction:**\r\nAn acid reacts with a base to form salt and water.\r\nAcid + Base $\\rightarrow$ Salt + Water\r\n$HCl + NaOH \\rightarrow NaCl + H_2O$\r\n\r\n---\r\n## 🔥 4. EXOTHERMIC & ENDOTHERMIC REACTIONS\r\n\r\n### Exothermic Reaction (Exo = Exit)\r\nA reaction that **releases** heat energy into the surroundings. The surroundings get warmer.\r\n**Think:** Burning wood, explosion of a firecracker.\r\n**How to write it:** Heat is shown as a product.\r\nC + $O_2 \\rightarrow CO_2$ + **Heat**\r\n\r\n### Endothermic Reaction (Endo = Enter)\r\nA reaction that **absorbs** heat energy from the surroundings. The surroundings get colder.\r\n**Think:** Melting ice, cooking food.\r\n**How to write it:** Heat is shown as a reactant.\r\n$N_2 + O_2$ + **Heat** $\\rightarrow 2NO$\r\n\r\n---\r\n## ⚡ 5. RATE OF REACTION & FACTORS AFFECTING IT\r\nThe **rate of a chemical reaction** is the speed at which reactants are converted into products. Some factors can change this speed:\r\n\r\n1.  **Temperature:** 🔥 Increasing the temperature generally increases the reaction rate. (Molecules move faster and collide more often).\r\n    * **Example:** Food cooks faster at a higher temperature.\r\n2.  **Concentration:** 💧 Increasing the concentration of reactants increases the reaction rate. (More particles are packed into the same space, so they collide more).\r\n    * **Example:** A concentrated acid reacts faster than a dilute one.\r\n3.  **Surface Area:** पाउडर Increasing the surface area of a solid reactant increases the reaction rate. (More particles are exposed to react).\r\n    * **Example:** Powdered sugar dissolves faster in water than a sugar cube.\r\n4.  **Catalyst:** 🦸‍♂️ A substance that changes the rate of a reaction without being consumed itself.\r\n    * **Positive Catalyst (Promoter):** Speeds up a reaction. E.g., Manganese dioxide ($MnO_2$) speeds up the decomposition of hydrogen peroxide.\r\n    * **Negative Catalyst (Inhibitor):** Slows down a reaction. E.g., Glycerine slows down the decomposition of hydrogen peroxide.\r\n5.  **Light:** ☀️ Some reactions are triggered or sped up by light (photochemical reactions).\r\n    * **Example:** Photosynthesis in plants. $H_2 + Cl_2 \\xrightarrow{Sunlight} 2HCl$.\r\n6.  **Pressure:** 💨 For reactions involving gases, increasing the pressure increases the reaction rate. (Forces gas particles closer together, leading to more collisions).\r\n    * **Example:** The Haber process for making ammonia: $N_2(g) + 3H_2(g) \\xrightarrow{High \\ Pressure} 2NH_3(g)$.\r\n\r\n---\r\n## 📋 6. COMPLETE EXERCISE SOLUTIONS\r\n### **1. Define the following:**\r\n**a. Chemical Reaction:** A process that leads to the chemical transformation of one set of chemical substances (reactants) to another (products).\r\n**b. Endothermic Reaction:** A chemical reaction that absorbs heat from its surroundings.\r\n**c. Catalyst:** A substance that alters the rate of a chemical reaction without undergoing any permanent chemical change itself.\r\n**d. Neutralization Reaction:** A type of double displacement reaction where an acid and a base react to form salt and water.\r\n\r\n### **2. Answer the following questions:**\r\n**a. What are the conditions required for a chemical reaction? Explain any three.**\r\n**Answer:** The conditions required are heat, light, pressure, catalyst, concentration, and surface area.\r\n1.  **Heat:** Many reactions need heat to start. For example, heating potassium chlorate ($KClO_3$) causes it to decompose. $2KClO_3 \\xrightarrow{Heat} 2KCl + 3O_2$.\r\n2.  **Light:** Some reactions are photochemical. For example, hydrogen and chlorine react in the presence of sunlight. $H_2 + Cl_2 \\xrightarrow{Sunlight} 2HCl$.\r\n3.  **Pressure:** This is crucial for gas reactions. In the Haber process, high pressure is used to produce ammonia. $N_2(g) + 3H_2(g) \\xrightarrow{Pressure} 2NH_3(g)$.\r\n\r\n**b. Describe an experiment to show that the rate of reaction increases with an increase in temperature.**\r\n**Answer:**\r\n**Materials:** Two beakers, oxalic acid, dilute sulphuric acid, potassium permanganate ($KMnO_4$) solution, burner.\r\n**Procedure:**\r\n1.  Take equal amounts of oxalic acid, sulphuric acid, and pink-colored $KMnO_4$ solution in two beakers, \'A\' and \'B\'.\r\n2.  Gently heat beaker \'A\' to about 60°C. Do not heat beaker \'B\'.\r\n3.  Observe the time it takes for the pink color to disappear in both beakers.\r\n**Observation:** The pink color in the heated beaker \'A\' disappears much faster than in the cold beaker \'B\'.\r\n**Conclusion:** This proves that increasing the temperature increases the rate of a chemical reaction.\r\n\r\n### **3. Differentiate Between:**\r\n**a. Combination Reaction and Decomposition Reaction**\r\n| Combination Reaction | Decomposition Reaction |\r\n|---|---|\r\n| Two or more reactants form one product. | One reactant breaks into two or more products.|\r\n| General Form: A + B $\\rightarrow$ AB | General Form: AB $\\rightarrow$ A + B |\r\n| It is like \'synthesis\' or \'building up\'.| It is like \'breaking down\'. |\r\n| E.g., $2Mg + O_2 \\rightarrow 2MgO$ | E.g., $CaCO_3 \\rightarrow CaO + CO_2$ |\r\n\r\n**b. Positive Catalyst and Negative Catalyst**\r\n| Positive Catalyst (Promoter) | Negative Catalyst (Inhibitor) |\r\n|---|---|\r\n| Increases the rate of a chemical reaction.| Decreases the rate of a chemical reaction. |\r\n| It provides an alternative path with lower activation energy. | It increases the activation energy. |\r\n| Example: $MnO_2$ in the decomposition of $H_2O_2$.| Example: Glycerine in the decomposition of $H_2O_2$.|\r\n\r\n### **4. Give reasons:**\r\n**a. An acid-base reaction is called a neutralization reaction.**\r\n**Answer:** Because in this reaction, the acidic properties of the acid and the basic properties of the base cancel or \"neutralize\" each other, resulting in the formation of a neutral salt and water.\r\n\r\n**b. Paper burning to ash is a chemical change.**\r\n**Answer:** Because a new substance (ash, carbon dioxide, etc.) with entirely different properties is formed. This change is permanent and irreversible; you cannot turn the ash back into paper.\r\n\r\n**c. Powdered marble reacts faster with acid than marble chips.**\r\n**Answer:** Powdered marble has a much larger surface area than marble chips. This allows more particles of the acid to come into contact and react with the marble simultaneously, leading to a faster reaction rate.\r\n\r\n### **5. Change into balanced chemical equations:**\r\n**a. Hydrogen + Chlorine $\\rightarrow$ Hydrogen chloride**\r\n**Ans:** $H_2 + Cl_2 \\rightarrow 2HCl$\r\n**b. Potassium chlorate $\\rightarrow$ Potassium chloride + Oxygen**\r\n**Ans:** $2KClO_3 \\rightarrow 2KCl + 3O_2$\r\n**c. Aluminium + Sulphuric acid $\\rightarrow$ Aluminium sulphate + Hydrogen**\r\n**Ans:** $2Al + 3H_2SO_4 \\rightarrow Al_2(SO_4)_3 + 3H_2$\r\n**d. Iron + Oxygen $\\rightarrow$ Iron(III) oxide (rust)**\r\n**Ans:** $4Fe + 3O_2 \\rightarrow 2Fe_2O_3$\r\n**e. Water + Carbon dioxide $\\rightarrow$ Glucose + Oxygen (Photosynthesis)**\r\n**Ans:** $6H_2O + 6CO_2 \\rightarrow C_6H_{12}O_6 + 6O_2$\r\n\r\n---\r\n## ✅ 7. CHAPTER CHECKLIST & EXAM TIPS\r\n**Exam Hotspots 🔥:**\r\n-   **Balancing Equations:** This is a guaranteed question. Practice the M-N-O-H rule.\r\n-   **Types of Reactions:** Be ready to define and give one example for each of the four types. Single and Double displacement are very common.\r\n-   **Factors Affecting Rate:** The \"Give Reason\" questions often come from this topic (e.g., why powdered salt dissolves faster).\r\n\r\n**Your Pre-Exam Checklist:**\r\n- [ ] I can define a chemical reaction.\r\n- [ ] I can balance any given chemical equation.\r\n- [ ] I can identify the four main types of reactions.\r\n- [ ] I can explain the difference between exothermic and endothermic reactions.\r\n- [ ] I can list and explain at least three factors affecting the reaction rate.\r\n---\r\n## 🎊 CONCLUSION\r\nAnd that\'s a wrap on Chemical Reactions! You\'ve learned the secret language of chemists. Remember, chemistry is all about patterns. Once you understand the basic types and rules, you can predict how thousands of different substances will interact. Use these notes, practice the balancing trick, and you\'ll be all set to ace this chapter in your SEE exams.\r\n**Your Formula for Success:** Practice + Understanding Analogies + Revision = Top Marks!', 1, '2025-07-25 01:11:38', '2025-09-16 15:20:38'),
(89, 11501, '# Classification of Elements - Grade 10 (SEE) Science\r\n## Complete Chapter Notes with All Exercises - NEB Curriculum\r\n---\r\n## 🎯 Chapter Overview\r\n**Welcome to the ultimate guide for \"Classification of Elements\"!** Think of the periodic table as the ultimate cheat sheet for all of chemistry. This chapter will teach you how to read and understand this amazing tool. These notes are designed to be super easy to follow, with fun tricks and clear explanations, making you a master of the periodic table.\r\n**This chapter is crucial for your SEE exam as it forms the foundation of chemistry.** We\'ll journey through the history of the periodic table, from early attempts to the Modern Periodic Table we use today. You\'ll learn how to find any element\'s \"address\" (its group and period), understand its properties, and predict how it will behave. **Every single exercise from your textbook is solved here**, ensuring you\'re fully prepared to tackle any question.\r\n**Weightage:** 7-9 marks in SEE examination\r\n**Time Required:** 15-20 periods\r\n---\r\n## 📚 Learning Objectives\r\nAfter studying this chapter, you will be able to:\r\n- State Mendeleev\'s and the Modern Periodic Law.\r\n- Explain the merits and demerits of Mendeleev\'s Periodic Table.\r\n- Describe the structure of the Modern Periodic Table (groups and periods).\r\n- Find the position (group, period, block) of an element from its electronic configuration.\r\n- Classify elements into s, p, d, and f blocks.\r\n- Understand periodic trends like atomic size and reactivity.\r\n- Differentiate between various types of elements like alkali metals, halogens, and inert gases.\r\n---\r\n## 📜 1. THE STORY OF THE PERIODIC TABLE\r\nFor a long time, chemists had a messy collection of elements with no organization. Several scientists tried to bring order to this chaos.\r\n\r\n### A. Mendeleev\'s Periodic Table (The Genius First Draft)\r\nDmitri Mendeleev, a Russian chemist, was the first to create a truly useful periodic table.\r\n- **Mendeleev\'s Periodic Law:** *\"The physical and chemical properties of elements are the periodic functions of their **atomic masses**.\"*\r\n- **Merits (What he got right):**\r\n    1.  **Systematic Study:** He arranged all 63 known elements in a systematic way.\r\n    2.  **Predicted New Elements:** He left gaps for elements that hadn\'t been discovered yet and even predicted their properties! (e.g., Eka-silicon, which later became Germanium).\r\n    3.  **Correction of Atomic Mass:** He corrected the atomic masses of some elements.\r\n- **Demerits (The Problems):**\r\n    1.  **Position of Hydrogen:** Hydrogen behaves like both Group 1 metals and Group 17 non-metals, so he couldn\'t give it a fixed position.\r\n    2.  **Position of Isotopes:** Isotopes of an element have different atomic masses but similar chemical properties. His table had no place for them.\r\n    3.  **Anomalous Pairs:** He had to place some heavier elements before lighter ones to match properties (e.g., Argon before Potassium).\r\n\r\n### B. The Modern Periodic Table (The Final Version)\r\nHenry Moseley, a brilliant young physicist, discovered that **atomic number** (the number of protons) is a more fundamental property of an element than atomic mass.\r\n- **Modern Periodic Law:** *\"The physical and chemical properties of elements are the periodic functions of their **atomic numbers**.\"*\r\nThis new law fixed all the problems in Mendeleev\'s table and gave us the table we use today.\r\n\r\n\r\n\r\n---\r\n## 🗺️ 2. NAVIGATING THE MODERN PERIODIC TABLE\r\nThe Modern Periodic Table is like a grid. Understanding its layout is key.\r\n- **Groups:** The 18 vertical columns are called **groups**.\r\n    - **Trick:** All elements in the same group have the **same number of valence electrons** (outermost electrons) and thus have **similar chemical properties**.\r\n- **Periods:** The 7 horizontal rows are called **periods**.\r\n    - **Trick:** All elements in the same period have the **same number of electron shells**.\r\n\r\n### How to Find an Element\'s \"Address\" (Block, Period, Group)\r\nThis is a super important skill! Just follow these steps using the sub-shell electronic configuration.\r\n\r\n**Example: Find the position of Sodium (Na), Atomic Number = 11**\r\n**Step 1: Write the electronic configuration.**\r\nNa (11) = $1s^2 \\ 2s^2 \\ 2p^6 \\ 3s^1$\r\n\r\n**Step 2: Find the Block, Period, and Group.**\r\n- **Block:** The last electron enters the **\'s\' sub-shell**. So, it\'s an **s-block** element.\r\n- **Period:** The highest shell number (the big number in front) is **3**. So, it\'s in the **3rd Period**.\r\n- **Group:** For s-block elements, the group number is the **number of electrons in the last s sub-shell**. There is **1** electron in 3s. So, it\'s in **Group 1 (IA)**.\r\n\r\n**Pro-Tricks for Finding the Group:**\r\n- For **s-block**: Group No. = No. of valence electrons (1 or 2).\r\n- For **p-block**: Group No. = 10 + No. of valence electrons (e.g., Chlorine has 7 valence electrons, so Group = 10 + 7 = 17).\r\n- For **d-block**: Group No. = No. of electrons in the last \'s\' sub-shell + No. of electrons in the last \'d\' sub-shell.\r\n\r\n---\r\n## 🏢 3. THE BLOCKS: NEIGHBORHOODS OF ELEMENTS\r\nElements are sorted into four main \"blocks\" or neighborhoods based on their electronic configuration.\r\n\r\n1.  **s-Block Elements (The Reactors):**\r\n    - **Groups:** 1 and 2.\r\n    - **Who are they?:** Highly reactive metals.\r\n    - **Group 1 (IA): Alkali Metals.** (e.g., Li, Na, K). They are soft, highly reactive metals that form strong alkalis with water.\r\n    - **Group 2 (IIA): Alkaline Earth Metals.** (e.g., Be, Mg, Ca). They are also reactive metals, commonly found in the Earth\'s crust.\r\n\r\n2.  **p-Block Elements (The Diverse Group):**\r\n    - **Groups:** 13 to 18.\r\n    - **Who are they?:** This block has it all: metals, non-metals, and metalloids.\r\n    - **Group 17 (VIIA): Halogens.** (e.g., F, Cl, Br). They are very reactive non-metals. The name means \"salt-formers\".\r\n    - **Group 18 (0): Noble/Inert Gases.** (e.g., He, Ne, Ar). They are unreactive because their outermost shell is completely full.\r\n\r\n3.  **d-Block Elements (Transition Metals):**\r\n    - **Groups:** 3 to 12.\r\n    - **Who are they?:** The classic metals like Iron (Fe), Copper (Cu), and Gold (Au). They are hard, have high melting points, often form colored compounds, and show variable valency.\r\n\r\n4.  **f-Block Elements (Inner Transition Metals):**\r\n    - **Who are they?:** The **Lanthanides** and **Actinides**. They are placed separately at the bottom to keep the main table from being too wide. Most actinides are radioactive.\r\n\r\n---\r\n## 📈 4. PERIODIC TRENDS\r\nAs you move across or down the periodic table, properties change in a predictable pattern.\r\n\r\n- **Atomic Size:**\r\n    - **Down a Group (↓): Increases.** Why? New electron shells are added, making the atom bigger.\r\n    - **Across a Period (→): Decreases.** Why? The number of protons in the nucleus increases, pulling the electron shells in more tightly.\r\n- **Reactivity of Metals:**\r\n    - **Down a Group (↓): Increases.** Why? The outermost electron is farther from the nucleus and easier to lose.\r\n    - **Example:** Potassium (K) is more reactive than Sodium (Na).\r\n- **Reactivity of Non-Metals:**\r\n    - **Down a Group (↓): Decreases.** Why? The atom is larger, so its ability to attract and gain an electron decreases.\r\n    - **Example:** Fluorine (F) is more reactive than Chlorine (Cl).\r\n\r\n---\r\n## 📋 5. COMPLETE EXERCISE SOLUTIONS\r\n### **1. Differentiate Between:**\r\n**a. Group and Period**\r\n| Groups | Periods |\r\n|---|---|\r\n| The 18 vertical columns. | The 7 horizontal rows. |\r\n| Elements have the same number of valence electrons. | Elements have the same number of electron shells.|\r\n| Elements have similar chemical properties. | Chemical properties change across the period. |\r\n\r\n**b. Mendeleev\'s Periodic Table and Modern Periodic Table**\r\n| Mendeleev\'s Periodic Table | Modern Periodic Table |\r\n|---|---|\r\n| Based on increasing **atomic mass**. | Based on increasing **atomic number**. |\r\n| Had defects like the position of isotopes.| These defects are solved. |\r\n| Contained 8 groups and 12 periods.| Contains 18 groups and 7 periods. |\r\n\r\n### **2. Give Reasons:**\r\n**a. Argon (Ar) is an inert gas.**\r\n**Answer:** Argon\'s atomic number is 18, and its electronic configuration is (2, 8, 8). Its outermost shell (valence shell) is completely filled with 8 electrons. This stable configuration makes it chemically unreactive or inert.\r\n\r\n**b. The members of Group 1 are called alkali metals.**\r\n**Answer:** Because they are highly reactive metals that react with water to form strong alkalis (water-soluble bases) and produce hydrogen gas. For example: $2Na + 2H_2O \\rightarrow 2NaOH + H_2 \\uparrow$.\r\n\r\n**c. Fluorine is more reactive than Chlorine.**\r\n**Answer:** Both are in Group 17. As we go down the group, atomic size increases. Fluorine is smaller than chlorine, so its nucleus has a stronger pull on incoming electrons. This allows it to gain an electron more easily, making it more reactive.\r\n\r\n**d. Lanthanides and Actinides are kept separately in the periodic table.**\r\n**Answer:** They are kept separately at the bottom to maintain the structure of the periodic table and to prevent it from becoming too wide. Their properties are also quite distinct from the d-block elements.\r\n\r\n### **3. Answer the following questions:**\r\n**a. State the Modern Periodic Law.**\r\n**Answer:** The Modern Periodic Law states that \"the physical and the chemical properties of elements are the periodic functions of their atomic numbers.\"\r\n\r\n**b. Write any two merits of Mendeleev\'s periodic table.**\r\n**Answer:**\r\n1.  It helped in the systematic study of elements.\r\n2.  Mendeleev left gaps for undiscovered elements and accurately predicted their properties.\r\n\r\n**c. An element \'X\' has atomic number 17.**\r\n**(i) Write its electronic configuration.**\r\n**(ii) Find its group, period, and block.**\r\n**(iii) Is it a metal or non-metal?**\r\n**Answer:**\r\n(i) **Electronic Configuration:** $1s^2 \\ 2s^2 \\ 2p^6 \\ 3s^2 \\ 3p^5$\r\n(ii) **Block:** p-block (last electron is in \'p\'). **Period:** 3 (highest shell is 3). **Group:** 10 + 7 (valence electrons) = **17**.\r\n(iii) It is a **non-metal** (it only needs one electron to complete its octet, so it gains electrons).\r\n\r\n---\r\n## ✅ 6. CHAPTER CHECKLIST & EXAM TIPS\r\n**Exam Hotspots 🔥:**\r\n-   **Laws:** Memorize both Mendeleev\'s and the Modern Periodic Law.\r\n-   **Finding Position:** Practice finding the group, period, and block for elements with atomic numbers 1-20. This is a very common question.\r\n-   **Periodic Trends:** \"Give Reason\" questions are almost always based on trends in atomic size and reactivity. Understand the \"why\" behind them.\r\n-   **Definitions:** Be clear on the definitions of alkali metals, halogens, inert gases, and transition metals.\r\n\r\n**Your Pre-Exam Checklist:**\r\n- [ ] I can state both periodic laws.\r\n- [ ] I can list two merits and two demerits of Mendeleev\'s table.\r\n- [ ] I can find the block, group, and period of an element (like Mg, Z=12).\r\n- [ ] I can explain why atomic size decreases across a period.\r\n- [ ] I can explain why potassium is more reactive than sodium.\r\n---\r\n## 🎊 CONCLUSION\r\nYou\'ve now unlocked the secrets of the periodic table! It\'s not just a chart; it\'s a powerful tool that brings order to the world of chemistry. By understanding its structure and patterns, you can predict the properties and behavior of elements. Keep practicing how to find an element\'s position and explaining the trends, and you\'ll be more than ready for your SEE exam.\r\n**Key to Success:** Learn the Laws + Practice Finding Positions + Understand the Trends = A+ in Chemistry!', 1, '2025-07-25 01:11:38', '2025-09-16 15:20:38'),
(90, 11507, '# Materials Used in Daily Life - Grade 10 (SEE) Science\r\n## Complete Chapter Notes with All Exercises - NEB Curriculum\r\n---\r\n## 🎯 Chapter Overview\r\n**Look around you! The chair you\'re sitting on, the glass you drink from, the clothes you wear—all are made of fascinating materials.** This chapter, \"Materials Used in Daily Life,\" uncovers the science behind everyday objects. These notes are your ultimate guide, making complex topics like glass, cement, plastics, and soaps incredibly simple and easy to remember.\r\n**This is a high-scoring and practical chapter for your SEE exam.** We\'ll explore how these materials are made, what makes them special, and why choosing the right material for a job is so important. With clear explanations, helpful tables, and solutions to every single textbook exercise, you\'ll be able to see the world around you with a chemist\'s eye!\r\n**Weightage:** 8-10 marks in SEE examination\r\n**Time Required:** 15-20 periods\r\n---\r\n## 📚 Learning Objectives\r\nAfter studying this chapter, you will be able to:\r\n- Identify the raw materials and manufacturing processes for glass, cement, ceramics, and plastics.\r\n- Differentiate between various types of glass, plastics, and fertilizers.\r\n- Explain the chemistry of soaps and detergents and how they clean.\r\n- Understand the role of fertilizers and insecticides in agriculture and their environmental impact.\r\n- Explain the importance of responsible use and management of man-made materials.\r\n---\r\n## 🧊 1. GLASS: The Supercooled Liquid\r\nGlass is a hard, brittle, transparent, and **amorphous** (non-crystalline) solid. Interestingly, it\'s often called a **supercooled liquid** because its molecules are arranged randomly, like a liquid, rather than in a fixed pattern like a true solid. This is why very old window panes are sometimes found to be thicker at the bottom.\r\n\r\n**Common Raw Materials:**\r\n- **Silica** or Sand ($SiO_2$) - The main ingredient.\r\n- **Sodium Carbonate** ($Na_2CO_3$) or Soda Ash - Lowers the melting point of silica.\r\n- **Calcium Carbonate** ($CaCO_3$) or Limestone - Makes the glass insoluble in water.\r\n\r\n### Types of Glass\r\n\r\n| Type of Glass | Key Raw Materials | Properties | Main Uses |\r\n|---|---|---|---|\r\n| **Soft Glass** (Soda-lime) | Silica + Soda Ash + Limestone | Low melting point, cheap, not heat-resistant. | Window panes, bottles, mirrors, light bulbs. |\r\n| **Hard Glass** (Potash-lime) | Silica + **Potassium Carbonate** + Limestone | High melting point, durable, resistant to chemicals. | Laboratory apparatus (beakers, flasks). |\r\n| **Pyrex Glass** (Borosilicate) | Silica + Soda Ash + **Boric Oxide** ($B_2O_3$) | Very heat resistant, low thermal expansion (doesn\'t crack on heating).| Lab equipment, ovenware, cookware. |\r\n| **Lead Crystal Glass** (Flint)| Silica + **Potassium Carbonate** + **Lead Oxide ($PbO$)** | Heavy, shiny, high refractive index (sparkles). | High-quality lenses, prisms, decorative items. |\r\n| **Water Glass** (Sodium Silicate)| Silica + Sodium Carbonate | **Soluble in water**, fireproof. | Fireproofing materials, adhesives, silica garden. |\r\n| **Quartz Glass** (Silica Glass) | Pure Silica ($SiO_2$) | Very high melting point (~1600°C), transparent to UV light. | Lenses for scientific instruments, optical fibers. |\r\n\r\n### Fun Fact: Coloring Glass\r\nTiny amounts of metal oxides are added to glass to give it color:\r\n- **Cobalt Oxide ($CoO$)** $\\rightarrow$ Blue Glass 💙\r\n- **Copper Oxide ($Cu_2O$)** $\\rightarrow$ Red Glass ❤️\r\n- **Nickel Oxide ($NiO$)** $\\rightarrow$ Black/Brown Glass 🖤\r\n---\r\n## 🧱 2. CEMENT & CONCRETE: The Binder of Our World\r\n**Cement** is a fine, grey powder made from limestone and clay. When mixed with water, it sets into a hard mass. This setting is a chemical process called **hydration** of calcium silicates and calcium aluminates.\r\n\r\n- **Manufacturing:**\r\n    1.  Limestone ($CaCO_3$) and clay are crushed and heated in a kiln to about 1500°C.\r\n    2.  This forms small, hard balls called **cement clinker**.\r\n    3.  The clinker is cooled and ground into a fine powder with 2-3% **gypsum** ($CaSO_4 \\cdot 2H_2O$).\r\n\r\n- **Why is Gypsum added?** **SUPER IMPORTANT!** Gypsum is added to **slow down the setting time of cement**. This gives workers more time to mix, transport, and apply it before it hardens, which also helps it achieve greater strength.\r\n\r\n### Cement Mixtures\r\n- **Mortar:** Cement + Sand + Water. Used for plastering and joining bricks.\r\n- **Concrete:** Cement + Sand + Gravel (small stones) + Water. Used for building floors, roofs, and pillars.\r\n- **RCC (Reinforced Cement Concrete):** Concrete with an internal framework of iron rods. The iron provides tensile strength, making RCC incredibly strong and suitable for bridges, dams, and large buildings. \r\n\r\n---\r\n##🏺 3. CERAMICS: The Art of Clay\r\n**Ceramics** are materials made from special clay called **kaolin** (a pure, white clay), which is then hardened by fire.\r\n\r\n- **Process:**\r\n    1.  Clay is mixed with water to make it pliable.\r\n    2.  It\'s molded into the desired shape (e.g., a cup or tile).\r\n    3.  It\'s dried and then fired in a kiln at high temperatures.\r\n    4.  A process called **glazing** is often done, where a glassy coating is applied to make the ceramic waterproof, smooth, and decorative.\r\n\r\n- **Properties:** Hard, brittle, excellent insulators of heat and electricity, resistant to chemicals.\r\n- **Uses:** Crockery (cups, plates), tiles, bricks, electrical insulators.\r\n\r\n---\r\n## 🧴 4. PLASTICS & FIBERS: The Marvels of Polymerization\r\n**Plastics** are synthetic materials made of large molecules called **polymers**. Polymers are long chains made by linking many small repeating units called **monomers**.\r\n**Monomer + Monomer + ... $\\rightarrow$ Polymer** (This process is called Polymerization)\r\n\r\n### Thermoplastics vs. Thermosetting Plastics\r\n**Analogy:** Thermoplastics are like **butter**—you can melt it and solidify it again and again. Thermosetting plastics are like a **cake**—once you bake it, you can\'t un-bake it!\r\n\r\n| Feature | Thermoplastics | Thermosetting Plastics |\r\n|---|---|---|\r\n| **Effect of Heat** | Soften on heating, can be remolded. | Do not soften on heating; they char and harden permanently. |\r\n| **Examples** | **PVC** (Polyvinyl Chloride) - pipes. **Polythene** - plastic bags. | **Bakelite** - electrical switches, cooker handles. **Melamine** - unbreakable dinnerware. |\r\n| **Raw Materials**| Ethene for Polythene; Vinyl Chloride for PVC. | **Phenol (Carbolic Acid) + Formaldehyde** for Bakelite. |\r\n\r\n### Fibers\r\nFibers are thin, thread-like structures.\r\n- **Natural Fibers:** Obtained from plants and animals (e.g., Cotton, Silk, Wool).\r\n- **Synthetic Fibers:** Man-made polymers (e.g., Nylon, Orlan, Rayon).\r\n---\r\n##🧼 5. SOAPS & DETERGENTS: The Chemistry of Cleaning\r\n\r\n### Soap\r\n- **What is it?** A sodium or potassium salt of a long-chain fatty acid. (e.g., Sodium Stearate).\r\n- **Raw Materials:** Animal fat or vegetable oil + an Alkali (like NaOH).\r\n- **Saponification:** The process of making soap by boiling fats/oils with an alkali.\r\n  **Fat/Oil + Alkali $\\xrightarrow{Heat}$ Soap + Glycerol**\r\n- **Problem:** Soap does not work well in **hard water** as it forms insoluble scum.\r\n\r\n### Detergent\r\n- **What is it?** A synthetic cleansing agent made from petrochemicals (e.g., Sodium Lauryl Sulphate).\r\n- **Advantage:** Detergents work perfectly in both **soft and hard water** because they don\'t form scum. They also have a stronger cleansing action.\r\n---\r\n## 🌱 6. FERTILIZERS & INSECTICIDES: Feeding & Protecting Plants\r\n\r\n### Fertilizers\r\nFertilizers are substances added to soil to supply essential nutrients for plant growth.\r\n\r\n| Nutrients | Role in Plants | Deficiency Symptoms |\r\n|---|---|---|\r\n| **Nitrogen (N)** | Promotes rapid leaf and stem growth; essential for protein. | Stunted growth, **yellowing of leaves (chlorosis)**. |\r\n| **Phosphorus (P)**| Essential for root development, flowering, and seed formation. | Poor root growth, delayed ripening of fruits. |\r\n| **Potassium (K)**| Improves overall plant health, strong stems, disease resistance. | Weak stems, unhealthy roots and shoots. |\r\n\r\n- **Organic Fertilizer (Compost):** Made from decayed organic matter. It\'s eco-friendly and improves soil structure.\r\n- **Chemical Fertilizer:** Synthetically produced. **NPK fertilizers** are called \"complete fertilizers\" because they contain all three primary nutrients.\r\n\r\n### Insecticides\r\nChemicals used to kill insects and pests.\r\n- **Example:** DDT (Dichlorodiphenyl Trichloroethane).\r\n- **Impact:** Overuse causes **chemical pollution**, harming beneficial organisms and contaminating the food chain.\r\n---\r\n## 🌍 7. ENVIRONMENTAL IMPACT & WASTE MANAGEMENT\r\nThe production and disposal of man-made materials can cause **chemical pollution**.\r\n\r\n### Solid Waste Management\r\nThis is the process of collecting, transporting, processing, and disposing of waste materials.\r\n- **Biodegradable Waste:** Wastes that can be decomposed by microorganisms (e.g., food scraps, paper).\r\n- **Non-biodegradable Waste:** Wastes that cannot be decomposed naturally (e.g., plastic, glass, metals).\r\n\r\n**Methods of Disposal:**\r\n- **Landfill:** Burying waste in large pits.\r\n- **Incineration:** Burning solid waste at very high temperatures (around 1000°C).\r\n- **3R\'s:** The best approach: **Reduce, Reuse, and Recycle**.\r\n---\r\n## 📋 8. COMPLETE EXERCISE SOLUTIONS\r\n### **1. Differentiate Between:**\r\n**a. Soft Glass and Hard Glass**\r\n| Soft Glass (Soda-lime) | Hard Glass (Potash-lime) |\r\n|---|---|\r\n| Made using sodium carbonate ($Na_2CO_3$). | Made using potassium carbonate ($K_2CO_3$). |\r\n| Has a lower melting point. | Has a higher melting point and is more durable. |\r\n| Used for bottles, window panes. | Used for heat-resistant lab apparatus. |\r\n\r\n**b. Organic and Chemical Fertilizers**\r\n| Organic Fertilizers | Chemical Fertilizers |\r\n|---|---|\r\n| Made from decaying plants and animals. | Made from synthetic chemicals. |\r\n| Improves soil health and texture. | Provides specific nutrients but can degrade soil over time.|\r\n| Eco-friendly; does not cause pollution. | Overuse leads to water and soil pollution. |\r\n\r\n### **2. Give Reasons:**\r\n**a. Gypsum is added while manufacturing cement.**\r\n**Answer:** Gypsum is added to cement to **slow down its initial setting time**. This provides sufficient time for mixing and application before it hardens.\r\n\r\n**b. Bakelite is used for making handles of pressure cookers.**\r\n**Answer:** Bakelite is a **thermosetting plastic** and a **poor conductor of heat**. It does not soften upon heating, making it a safe and ideal material for insulating handles on hot cookware.\r\n\r\n**c. Lead crystal glass is used for expensive decorative items.**\r\n**Answer:** Lead crystal glass contains lead oxide, which gives it a **high refractive index**. This makes the glass sparkle brilliantly when it catches the light, making it desirable for expensive glassware and decorative pieces.\r\n\r\n**d. Detergent water is not useful for plants.**\r\n**Answer:** Detergents contain synthetic chemicals (like phosphates) that can be harmful to plant life and can alter the pH of the soil, making it unsuitable for growth.\r\n\r\n**e. Plastic is used for making surgical equipment.**\r\n**Answer:** Medical-grade plastics are used because they are lightweight, can be easily sterilized, are shatter-proof, and are chemically inert, meaning they do not react with body tissues.\r\n\r\n### **3. Answer the following questions:**\r\n**a. What is glazing?**\r\n**Answer:** Glazing is the process of applying a thin, glassy coating to ceramic objects and then firing them. This makes the ceramic shiny, smooth, waterproof, and more durable.\r\n\r\n**b. How is compost manure prepared?**\r\n**Answer:** Compost manure is prepared by collecting biodegradable wastes (like vegetable peels, leaves, animal dung) in a pit. The waste is layered with soil and left to decompose for 3-4 months. Microorganisms break down the organic matter into nutrient-rich humus, which is an excellent fertilizer.\r\n\r\n**c. Why are plastics so widely used?**\r\n**Answer:** Plastics are widely used because they are lightweight, strong, durable, cheap, waterproof, and can be easily molded into any shape. They are also poor conductors of heat and electricity and do not corrode.\r\n---\r\n## ✅ 9. CHAPTER CHECKLIST & EXAM TIPS\r\n**Exam Hotspots 🔥:**\r\n-   **Give Reasons:** This section is the most important. Master the reasons for gypsum in cement, Bakelite in handles, Pyrex in labs, and why detergents are better.\r\n-   **Differentiations:** Be perfect with the tables for Soap vs. Detergent, Thermoplastics vs. Thermosetting, and Soft vs. Hard Glass.\r\n-   **Definitions:** Know the definitions of Saponification, Polymerization, Mortar, Concrete, RCC, and Glazing.\r\n-   **Types of Glass:** Remember the special raw material and one key use for each type of glass.\r\n\r\n**Your Pre-Exam Checklist:**\r\n- [ ] I can name the raw materials for ordinary glass and cement.\r\n- [ ] I can explain why gypsum is added to cement.\r\n- [ ] I can differentiate between thermoplastics and thermosetting plastics with examples.\r\n- [ ] I can explain why detergents work in hard water but soaps do not.\r\n- [ ] I can list two benefits of organic fertilizers over chemical fertilizers.\r\n- [ ] I can define solid waste management and name two methods of disposal.\r\n---\r\n## 🎊 CONCLUSION\r\nThe materials we use every day are a product of brilliant chemistry. From the glass in our windows to the cement in our homes, understanding their properties helps us appreciate the world and make smarter choices. This chapter connects directly to our lives and highlights our responsibility to manage these materials sustainably to protect our environment.\r\n**Key to Success:** Connect Concepts to Real-Life Objects + Master the \'Give Reasons\' + Revise the Differences = Excellent Score!', 1, '2025-07-25 01:11:38', '2025-09-16 15:20:38');
INSERT INTO `course_notes_content` (`id`, `topic_id`, `content`, `markdown_format`, `created_at`, `updated_at`) VALUES
(91, 11505, '# Metals - Grade 10 (SEE) Science\r\n## Complete Chapter Notes with All Exercises - NEB Curriculum\r\n---\r\n## 🎯 Chapter Overview\r\n**From the iron in our buildings to the gold in our jewelry and the copper in our wires, metals are the backbone of our modern world.** This chapter, \"Metals,\" dives into the fascinating properties, occurrence, and uses of some of the most important metallic elements. These notes are designed to be your complete guide, making it easy to master the concepts.\r\n**This is a core chapter in chemistry with significant weightage in the SEE exam.** We will cover the fundamental differences between minerals and ores, explore the reactivity of metals, and take a deep dive into the properties and uses of Iron, Aluminium, Copper, Silver, and Gold. Every question from your textbook, including definitions, give reasons, and differentiations, is solved here with clear, step-by-step explanations.\r\n**Weightage:** 7-9 marks in SEE examination\r\n**Time Required:** 15-20 periods\r\n---\r\n## 📚 Learning Objectives\r\nAfter studying this chapter, you will be able to:\r\n- Differentiate between minerals and ores.\r\n- Understand why metals occur in free (native) or combined states.\r\n- Describe the physical properties of key metals like Iron, Aluminium, and Copper.\r\n- Write the electronic configuration and identify the position of these metals in the periodic table.\r\n- List the main ores of Iron, Aluminium, Copper, Silver, and Gold.\r\n- Explain the various uses of these metals by linking them to their properties.\r\n- Arrange metals in order of their reactivity.\r\n---\r\n## 💎 1. Metallurgy Basics: Minerals, Ores & Reactivity\r\n\r\n### Minerals vs. Ores\r\nThis is a fundamental concept in metallurgy (the science of metals).\r\n**Analogy:** Think of plants in a garden. All apple trees are plants, but not all plants are apple trees. Similarly...\r\n**All ores are minerals, but not all minerals are ores.**\r\n\r\n| Feature | Minerals | Ores |\r\n|---|---|---|\r\n| **Definition** | Naturally occurring, pure inorganic substances, usually in a crystalline form. | Minerals from which metals can be extracted **profitably and conveniently**. |\r\n| **Metal Content**| May contain a low percentage of metal. | Contain a high percentage of metal. |\r\n| **Extraction** | It is not always profitable to extract metal from all minerals. | It is always profitable to extract metal from ores. |\r\n| **Example**| Clay ($Al_2O_3 \\cdot 2SiO_2 \\cdot 2H_2O$) is a mineral of aluminium. | Bauxite ($Al_2O_3 \\cdot 2H_2O$) is the main **ore** of aluminium. |\r\n\r\n### Occurrence of Metals\r\n- **Free/Native State:** Less reactive metals do not easily react with air, water, or other chemicals. They are found in their pure, elemental form in nature.\r\n  - **Examples:** Gold (Au), Silver (Ag), Platinum (Pt).\r\n- **Combined State:** Most metals are reactive and are found in nature combined with other elements, forming compounds like oxides, sulphides, and carbonates. These compounds are the minerals and ores.\r\n  - **Examples:** Iron (Fe), Aluminium (Al), Copper (Cu), Zinc (Zn).\r\n\r\n### The Reactivity Series of Metals 👑\r\nThis is a \"power ranking\" of metals from most reactive to least reactive. It\'s super important for understanding their properties.\r\n\r\n| Metal | Symbol | Reactivity | Mnemonic |\r\n|---|---|---|---|\r\n| Potassium | K | **Most Reactive** | **P**lease |\r\n| Sodium | Na | | **S**top |\r\n| Calcium | Ca | | **C**alling |\r\n| Magnesium | Mg | | **M**e |\r\n| Aluminium | Al | | **A** |\r\n| Zinc | Zn | | **Z**ebra |\r\n| Iron | Fe | | **I** |\r\n| Lead | Pb | | **L**ike |\r\n| Hydrogen | (H) | (Reference) | **H**er |\r\n| Copper | Cu | | **C**all |\r\n| Mercury | Hg | | **S**mart |\r\n| Silver | Ag | | **G**oat |\r\n| Gold | Au | **Least Reactive** | |\r\n\r\n---\r\n## 🔬 2. A Detailed Look at Important Metals\r\n\r\n### A. Iron (Fe)\r\n- **Introduction:** The most widely used metal, known for its strength.\r\n- **Symbol:** Fe | **Atomic No:** 26 | **Atomic Mass:** 56 | **Valency:** 2 (ferrous), 3 (ferric)\r\n- **Position & E-Configuration:**\r\n  - **Period:** 4, **Group:** 8 (VIII)\r\n  - **Sub-shell:** $1s^2 \\ 2s^2 \\ 2p^6 \\ 3s^2 \\ 3p^6 \\ 4s^2 \\ 3d^6$\r\n- **Ores:** **Haematite ($Fe_2O_3$)**, Magnetite ($Fe_3O_4$), Iron Pyrite ($FeS_2$).\r\n- **Physical Properties:**\r\n  - Silvery-grey, lustrous metal.\r\n  - Malleable and ductile.\r\n  - Good conductor of heat and electricity.\r\n  - High density and high melting point.\r\n- **Uses:**\r\n  1.  Used to manufacture **steel**, a vital alloy.\r\n  2.  Used in construction (rods, beams, bridges).\r\n  3.  Used for making machinery, tools, and vehicles.\r\n  4.  Used to make magnets.\r\n\r\n### B. Aluminium (Al)\r\n- **Introduction:** A remarkably light and corrosion-resistant metal.\r\n- **Symbol:** Al | **Atomic No:** 13 | **Atomic Mass:** 27 | **Valency:** 3\r\n- **Position & E-Configuration:**\r\n  - **Period:** 3, **Group:** 13 (IIIA)\r\n  - **Sub-shell:** $1s^2 \\ 2s^2 \\ 2p^6 \\ 3s^2 \\ 3p^1$\r\n- **Ores:** **Bauxite ($Al_2O_3 \\cdot 2H_2O$)**, Cryolite ($Na_3AlF_6$), Kaolin (China clay).\r\n- **Physical Properties:**\r\n  - Silvery-white, lightweight metal.\r\n  - Malleable and ductile.\r\n  - Excellent conductor of heat and electricity.\r\n  - Highly resistant to corrosion due to a protective oxide layer.\r\n- **Uses:**\r\n  1.  Used to make aeroplane and automobile parts because it\'s light and strong.\r\n  2.  Used for making cooking utensils.\r\n  3.  Used for making **aluminium foil** for wrapping food.\r\n  4.  Used in electrical cables as a cheaper alternative to copper.\r\n\r\n### C. Copper (Cu)\r\n- **Introduction:** One of the first metals used by humans, essential for electrical wiring.\r\n- **Symbol:** Cu | **Atomic No:** 29 | **Atomic Mass:** 64 | **Valency:** 1 (cuprous), 2 (cupric)\r\n- **Position & E-Configuration:**\r\n  - **Period:** 4, **Group:** 11 (IB) - A **Coinage Metal**.\r\n  - **Sub-shell:** $1s^2 \\ 2s^2 \\ 2p^6 \\ 3s^2 \\ 3p^6 \\ 4s^1 \\ 3d^{10}$ (Note: exceptional configuration for stability)\r\n- **Ores:** **Copper Pyrite ($CuFeS_2$)**, Chalcocite/Copper Glance ($Cu_2S$), Cuprite ($Cu_2O$).\r\n- **Physical Properties:**\r\n  - Reddish-brown metal with a bright lustre.\r\n  - Highly malleable and ductile.\r\n  - Excellent conductor of electricity (second only to silver).\r\n- **Uses:**\r\n  1.  Used extensively for making **electrical wires and cables**.\r\n  2.  Used for making water pipes and heating utensils.\r\n  3.  Used for making coins and statues.\r\n  4.  Used in electroplating.\r\n\r\n### D. Silver (Ag)\r\n- **Introduction:** A precious metal known for its brilliant lustre and conductivity.\r\n- **Symbol:** Ag | **Atomic No:** 47 | **Atomic Mass:** 108 | **Valency:** 1\r\n- **Position & E-Configuration:**\r\n  - **Period:** 5, **Group:** 11 (IB) - A **Coinage Metal**.\r\n  - **Sub-shell:** [Kr] $5s^1 \\ 4d^{10}$\r\n- **Ores:** **Argentite/Silver Glance ($Ag_2S$)**. Also found in a native state.\r\n- **Uses:**\r\n  1.  Used for making jewellery and decorative items.\r\n  2.  Used for making high-quality mirrors.\r\n  3.  Used in dentistry for fillings.\r\n  4.  Silver salts are used in photography.\r\n\r\n### E. Gold (Au)\r\n- **Introduction:** The most prized precious metal, known for its beauty and unreactivity. The \"King of Metals\".\r\n- **Symbol:** Au | **Atomic No:** 79 | **Atomic Mass:** 197 | **Valency:** 1 (aurous), 3 (auric)\r\n- **Position & E-Configuration:**\r\n  - **Period:** 6, **Group:** 11 (IB) - A **Coinage Metal**.\r\n  - **Sub-shell:** [Xe] $6s^1 \\ 4f^{14} \\ 5d^{10}$\r\n- **Ores:** Mostly found in **native state** (free gold) in alluvial sand and quartz veins.\r\n- **Uses:**\r\n  1.  Used for making valuable **jewellery and ornaments**.\r\n  2.  Used for making coins and medals.\r\n  3.  Used in dentistry for making crowns.\r\n  4.  Used for electroplating other metals to give a golden finish.\r\n---\r\n## 📋 3. COMPLETE EXERCISE SOLUTIONS\r\n\r\n### **1. Differentiate Between:**\r\n**a. Minerals and Ores**\r\n| Minerals | Ores |\r\n|---|---|\r\n| Naturally occurring inorganic substances from which metals can be extracted. | Minerals from which metals can be extracted **profitably and conveniently**. |\r\n| All minerals are not ores. | All ores are minerals. |\r\n| Example: Clay is a mineral of aluminium. | Example: Bauxite is the chief ore of aluminium. |\r\n\r\n### **2. Give Reasons:**\r\n**a. Iron is not found in a free state in nature.**\r\n**Answer:** Iron is a reactive metal. It readily reacts with oxygen and moisture in the atmosphere to form compounds like iron oxide (rust). Due to this high reactivity, it is found in a combined state as ores, not in a free state.\r\n\r\n**b. Parts of an aeroplane are made of aluminium but not iron.**\r\n**Answer:** Because aluminium is a **lightweight yet strong metal**, which is crucial for flight. Additionally, it is **rust-free** as it forms a protective layer of aluminium oxide, making it more durable than iron which rusts easily.\r\n\r\n**c. Gold and Silver are found in a native (free) state.**\r\n**Answer:** Gold and silver are very low in the reactivity series. They are unreactive and do not react with air, water, or other common chemicals under normal conditions. This stability allows them to exist in their pure, metallic form in nature.\r\n\r\n**d. Food is wrapped in aluminium foil.**\r\n**Answer:** Although aluminium is a reactive metal, it instantly reacts with oxygen in the air to form a very thin, tough, and non-reactive protective layer of aluminium oxide ($Al_2O_3$). This layer prevents the metal from reacting with the food and also acts as a barrier to moisture and air, keeping the food fresh.\r\n\r\n**e. Gold is called the \'king of metals\'.**\r\n**Answer:** Gold is extremely unreactive. It does not tarnish or react with air, water, acids, or alkalis. This exceptional resistance to corrosion and its lasting beauty and lustre earn it the title \'king of metals\'.\r\n\r\n### **3. Answer the following questions:**\r\n**a. List two main ores for the following metals:**\r\n- **Iron:** Haematite ($Fe_2O_3$), Magnetite ($Fe_3O_4$)\r\n- **Aluminium:** Bauxite ($Al_2O_3 \\cdot 2H_2O$), Kaolin (China Clay)\r\n- **Copper:** Copper Pyrite ($CuFeS_2$), Chalcocite ($Cu_2S$)\r\n- **Silver:** Argentite ($Ag_2S$), also found as native silver.\r\n\r\n**b. Why are gold and silver used for making jewellery?**\r\n**Answer:** Gold and silver are used for making jewellery for three main reasons:\r\n1.  **Lustre:** They have a bright, attractive shine.\r\n2.  **Unreactivity:** They do not rust or tarnish, so their beauty lasts.\r\n3.  **Malleability & Ductility:** They are very soft and can be easily beaten into thin sheets and drawn into intricate wires to create beautiful designs.\r\n\r\n**c. Arrange the following metals in ascending order of reactivity: Gold, Iron, Aluminium, Silver, Copper.**\r\n**Answer:** Ascending order (from least reactive to most reactive) is:\r\n**Gold < Silver < Copper < Iron < Aluminium**\r\n*(This order is based on the reactivity series.)*\r\n\r\n**d. Briefly write about the occurrence of metals in Nepal.**\r\n**Answer:** Nepal has deposits of several minerals. Iron ore is found in areas like Phulchowki (Lalitpur), Tanahun, and Chitwan. Copper deposits are known to exist in various parts of the country. Gold is found in its native state in the sands of rivers like the Rapti, Sunkoshi, and Kaligandaki.\r\n\r\n---\r\n## ✅ 4. CHAPTER CHECKLIST & EXAM TIPS\r\n**Exam Hotspots 🔥:**\r\n-   **Ores:** Memorizing the main ore of each metal (Haematite, Bauxite, Copper Pyrite) is a must.\r\n-   **Uses:** Be ready to list at least two uses for each metal. Questions often ask why a metal is suitable for a specific use (e.g., Aluminium in planes).\r\n-   **Give Reasons:** Questions on reactivity (why Gold is free, why Iron is not) are extremely common.\r\n-   **Reactivity Series:** Understanding this series helps answer many \"Give Reason\" questions.\r\n\r\n**Your Pre-Exam Checklist:**\r\n- [ ] I can differentiate between a mineral and an ore with an example.\r\n- [ ] I can name the main ore of Iron, Aluminium, and Copper.\r\n- [ ] I can explain why Gold is found in a native state.\r\n- [ ] I can explain why aeroplanes are made of aluminium.\r\n- [ ] I can list two important uses for each of the five metals studied.\r\n- [ ] I can write the electronic configuration of Iron and Aluminium.\r\n---\r\n## 🎊 CONCLUSION\r\nMetals are fundamental building blocks of civilization, each with a unique personality defined by its properties. Understanding them—from their atomic structure to their large-scale applications—is key to understanding chemistry. This chapter provides a solid foundation, not just for your exams, but for appreciating the material world around you.\r\n**Key to Success:** Link Properties to Uses + Master the Reactivity Series + Practice the \'Give Reasons\' = Top Marks!', 1, '2025-07-25 01:11:38', '2025-09-16 15:20:38'),
(92, 11504, '# Some Gases - Grade 10 (SEE) Science\r\n## Complete Chapter Notes with All Exercises - NEB Curriculum\r\n---\r\n## 🎯 Chapter Overview\r\n**Gases are all around us, playing vital roles in our environment and industries.** This chapter, \"Some Gases,\" focuses on two incredibly important gases: **Ammonia ($NH_3$)** and **Carbon Dioxide ($CO_2$)**. These detailed notes will guide you through their laboratory preparation, properties, and everyday uses in a simple and memorable way.\r\n**This is a fundamental chemistry chapter with a strong presence in the SEE exam, especially the diagram-based questions.** We will break down each step of the lab preparations, explain the chemistry behind their properties, and solve every single exercise from your textbook. By the end, you\'ll be an expert on these essential gases.\r\n**Weightage:** 8-10 marks in SEE examination\r\n**Time Required:** 15-20 periods\r\n---\r\n## 📚 Learning Objectives\r\nAfter studying this chapter, you will be able to:\r\n- Describe the laboratory preparation of Carbon Dioxide and Ammonia gas with labeled diagrams.\r\n- Explain the principles and chemical reactions involved in their preparation.\r\n- List the physical and chemical properties of both gases.\r\n- Identify and test for Carbon Dioxide and Ammonia.\r\n- State the conditions required for the industrial manufacture of Ammonia by Haber\'s Process.\r\n- Explain the various uses of Carbon Dioxide and Ammonia in daily life and industries.\r\n---\r\n## ⚫ Part A: Carbon Dioxide ($CO_2$)\r\nCarbon Dioxide is a crucial gas for life on Earth, used by plants for photosynthesis. It\'s also a major greenhouse gas.\r\n\r\n### 1. Laboratory Preparation of Carbon Dioxide\r\n\r\n**Principle:** Carbon dioxide is prepared in the lab by the reaction of a metallic carbonate (usually Calcium Carbonate, $CaCO_3$) with a dilute mineral acid (like Hydrochloric Acid, HCl).\r\n\r\n**Chemical Reaction:**\r\nCalcium Carbonate + Hydrochloric Acid $\\rightarrow$ Calcium Chloride + Water + Carbon Dioxide\r\n$CaCO_3 + 2HCl \\rightarrow CaCl_2 + H_2O + CO_2 \\uparrow$\r\n\r\n**Procedure:**\r\n1.  Marble chips or limestone pieces ($CaCO_3$) are placed in a Woulfe\'s bottle.\r\n2.  A thistle funnel and a delivery tube are fitted into its two mouths. The thistle funnel must be dipped below the acid level to prevent the gas from escaping through it.\r\n3.  Dilute HCl is poured into the bottle through the thistle funnel.\r\n4.  A brisk effervescence occurs, and $CO_2$ gas is produced.\r\n5.  The gas is collected in a gas jar by the **upward displacement of air**.\r\n\r\n\r\n\r\n[Image of the laboratory preparation of Carbon Dioxide gas]\r\n\r\n\r\n**Collection Method:** $CO_2$ is collected by **upward displacement of air** because it is about 1.5 times **heavier than air**. It cannot be collected over water as it is fairly soluble in it.\r\n\r\n### 2. Physical and Chemical Properties of $CO_2$\r\n\r\n**Physical Properties:**\r\n- It is a **colorless** and **odorless** gas.\r\n- It is **heavier than air**.\r\n- It is fairly soluble in water.\r\n- It can be easily liquefied and solidified. Solid $CO_2$ is called **Dry Ice**.\r\n\r\n**Chemical Properties:**\r\n- **Nature:** It is **acidic** in nature. It dissolves in water to form carbonic acid ($H_2CO_3$), which turns moist blue litmus paper red.\r\n  $CO_2 + H_2O \\rightarrow H_2CO_3$ (Carbonic Acid)\r\n- **Combustibility:** It is **non-combustible** and a **non-supporter of combustion**. This is why it\'s used in fire extinguishers.\r\n- **Reaction with Lime Water:**\r\n  - **Short Time:** When passed through lime water ($Ca(OH)_2$) for a short time, it turns milky due to the formation of insoluble Calcium Carbonate.\r\n    $Ca(OH)_2 + CO_2 \\rightarrow CaCO_3 \\downarrow + H_2O$\r\n  - **Long Time:** If excess $CO_2$ is passed, the milkiness disappears due to the formation of soluble Calcium Bicarbonate.\r\n    $CaCO_3 + H_2O + CO_2 \\rightarrow Ca(HCO_3)_2$ (Soluble)\r\n- **Reaction with Magnesium:** Although a non-supporter of burning, a burning magnesium ribbon continues to burn in a jar of $CO_2$ because the heat from Mg is enough to decompose $CO_2$.\r\n  $2Mg + CO_2 \\rightarrow 2MgO + C$\r\n\r\n### 3. Uses of Carbon Dioxide\r\n- **Photosynthesis:** Plants use $CO_2$ to make their food.\r\n- **Fire Extinguishers:** Used to put out fires.\r\n- **Soft Drinks:** To make carbonated beverages (soda, cola).\r\n- **Dry Ice:** Used as a refrigerant to keep things cold (like ice cream).\r\n- **Manufacturing:** Used to manufacture washing soda and urea.\r\n\r\n---\r\n## ⚪ Part B: Ammonia ($NH_3$)\r\nAmmonia is a colorless gas with a characteristic pungent smell. It is a vital industrial chemical, primarily used to make fertilizers.\r\n\r\n### 1. Laboratory Preparation of Ammonia\r\n\r\n**Principle:** Ammonia is prepared in the lab by heating an ammonium salt (like Ammonium Chloride, $NH_4Cl$) with a strong alkali (like Calcium Hydroxide, $Ca(OH)_2$).\r\n\r\n**Chemical Reaction:**\r\nAmmonium Chloride + Calcium Hydroxide $\\xrightarrow{Heat}$ Calcium Chloride + Water + Ammonia\r\n$2NH_4Cl + Ca(OH)_2 \\xrightarrow{Heat} CaCl_2 + 2H_2O + 2NH_3 \\uparrow$\r\n\r\n**Procedure & Setup:**\r\n1.  A mixture of $NH_4Cl$ and $Ca(OH)_2$ is taken in a hard glass test tube.\r\n2.  The test tube is clamped in a slanted position with its **mouth tilted downwards**. This is crucial to prevent the water vapor produced from condensing and trickling back, which could crack the hot test tube.\r\n3.  The gas produced is passed through a **drying tower** containing **Quicklime (CaO)** to remove moisture.\r\n4.  The dry gas is collected in an inverted gas jar by the **downward displacement of air**.\r\n\r\n\r\n\r\n[Image of the laboratory preparation of Ammonia gas]\r\n\r\n\r\n**Drying & Collection:**\r\n- **Drying Agent:** Only **Quicklime (CaO)** is used. Other agents like conc. $H_2SO_4$ (acid) or anhydrous $CaCl_2$ cannot be used because they react with ammonia (base).\r\n- **Collection Method:** Ammonia is collected by **downward displacement of air** because it is **lighter than air**. It cannot be collected over water because it is **highly soluble in water**.\r\n\r\n### 2. Industrial Manufacture: Haber\'s Process\r\nAmmonia is manufactured on a large scale by the direct combination of Nitrogen and Hydrogen.\r\n\r\n**Reaction:** $N_2(g) + 3H_2(g) \\rightleftharpoons 2NH_3(g) + Heat$\r\n\r\n**Necessary Conditions for Maximum Yield:**\r\n- **High Pressure:** 200 - 900 atmospheres.\r\n- **Optimal Temperature:** 450°C - 500°C.\r\n- **Catalyst:** Finely divided **Iron (Fe)**.\r\n- **Promoter:** Traces of **Molybdenum (Mo)** to increase the efficiency of the catalyst.\r\n\r\n### 3. Properties and Uses of Ammonia\r\n\r\n**Physical Properties:**\r\n- It is a **colorless** gas with a **strong, pungent smell**.\r\n- It is **lighter than air**.\r\n- It is **highly soluble in water**. A concentrated aqueous solution of ammonia is called **Liquor Ammonia** ($NH_4OH$).\r\n- It is non-combustible.\r\n\r\n**Chemical Properties:**\r\n- **Nature:** It is **basic** in nature. It turns moist red litmus paper blue and phenolphthalein solution pink.\r\n- **Reaction with Acids:** Being a base, it reacts with acids to form ammonium salts.\r\n  - $NH_3 + HCl \\rightarrow NH_4Cl$ (Ammonium Chloride)\r\n  - $2NH_3 + H_2SO_4 \\rightarrow (NH_4)_2SO_4$ (Ammonium Sulphate)\r\n\r\n**Uses of Ammonia:**\r\n- **Fertilizers:** Used to manufacture nitrogenous fertilizers like Urea and Ammonium Sulphate.\r\n- **Refrigerant:** Used as a coolant in ice plants and refrigerators.\r\n- **Cleaning Agent:** Its solution is used to remove grease and stains.\r\n- **Industrial Chemicals:** Used to make nitric acid, washing soda, and explosives.\r\n\r\n---\r\n## 📋 4. COMPLETE EXERCISE SOLUTIONS\r\n\r\n### **1. Give Reasons:**\r\n**a. Ammonia gas is collected by the downward displacement of air.**\r\n**Answer:** Because ammonia is **lighter than air**, so it rises and fills the gas jar from top to bottom, pushing the heavier air downwards and out. Also, it cannot be collected over water because it is **highly soluble** in it.\r\n\r\n**b. Concentrated $H_2SO_4$ is not used to dry ammonia gas.**\r\n**Answer:** Because ammonia ($NH_3$) is a basic gas and concentrated sulphuric acid ($H_2SO_4$) is an acid. They react with each other to form ammonium sulphate.\r\n$2NH_3 + H_2SO_4 \\rightarrow (NH_4)_2SO_4$\r\n\r\n**c. Carbon dioxide is used in fire extinguishers.**\r\n**Answer:** Because carbon dioxide is a **non-combustible gas** and a **non-supporter of combustion**. Being heavier than air, it displaces oxygen and cuts off the oxygen supply to the fire, thus extinguishing it.\r\n\r\n**d. The mouth of the test tube is tilted downwards during the lab preparation of ammonia.**\r\n**Answer:** Water is produced as a byproduct in the reaction. Tilting the test tube downwards allows this water vapor to flow out of the tube. This prevents it from condensing, trickling back onto the hot glass, and **cracking the test tube**.\r\n\r\n**e. A burning magnesium ribbon continues to burn in a jar of $CO_2$.**\r\n**Answer:** The intense heat from the burning magnesium is sufficient to break down the carbon dioxide molecule into carbon and oxygen. The oxygen released then supports the continued burning of the magnesium.\r\n$2Mg + CO_2 \\rightarrow 2MgO + C$\r\n\r\n### **2. Answer the following questions:**\r\n**a. What is Dry Ice? What is its use?**\r\n**Answer:** Dry ice is the solid form of carbon dioxide ($CO_2$), which forms at -78°C. It is used as a **refrigerant** for preserving food and in theatrical productions to create fog effects.\r\n\r\n**b. What happens when $CO_2$ is passed through lime water for a long time? Give a balanced equation.**\r\n**Answer:** First, the lime water turns milky due to the formation of insoluble calcium carbonate. When excess $CO_2$ is passed for a long time, the milkiness disappears due to the formation of water-soluble calcium bicarbonate.\r\n**Equation:** $CaCO_3 + H_2O + CO_2 \\rightarrow Ca(HCO_3)_2$\r\n\r\n**c. What is liquor ammonia? Name the compound formed in a gas jar of ammonia if the jar is moist.**\r\n**Answer:** Liquor ammonia is a concentrated aqueous solution of ammonia. If the gas jar is moist, ammonia gas will react with water ($H_2O$) to form **Ammonium Hydroxide ($NH_4OH$)**.\r\n**Equation:** $NH_3 + H_2O \\rightarrow NH_4OH$\r\n\r\n### **3. Diagrammatic Questions:**\r\n**Study the given figure for the lab preparation of $CO_2$ and answer:**\r\n\r\n**i. Find the mistake in the apparatus.**\r\n**Ans:** The thistle funnel is too short; its end must be **dipped inside the acid** to prevent the gas from escaping through it.\r\n**ii. What happens if quicklime is replaced by Conc. $H_2SO_4$ in the drying tower for ammonia prep?**\r\n**Ans:** Ammonia gas will react with the sulphuric acid to form ammonium sulphate. Therefore, the ammonia gas will not be collected.\r\n**Equation:** $2NH_3 + H_2SO_4 \\rightarrow (NH_4)_2SO_4$\r\n\r\n---\r\n## ✅ 5. CHAPTER CHECKLIST & EXAM TIPS\r\n**Exam Hotspots 🔥:**\r\n-   **Lab Prep Diagrams:** The labeled diagrams for both $CO_2$ and $NH_3$ preparation are extremely important. Practice drawing them.\r\n-   **Give Reasons:** Questions about collection methods, drying agents, and the tilted test tube are very frequently asked.\r\n-   **Haber\'s Process:** Memorize the five necessary conditions for the industrial production of ammonia.\r\n-   **Lime Water Test:** Be prepared to write both reactions (for a short time and a long time).\r\n\r\n**Your Pre-Exam Checklist:**\r\n- [ ] I can draw and label the lab preparation for both $CO_2$ and $NH_3$.\r\n- [ ] I can explain why $CO_2$ is collected by upward displacement of air.\r\n- [ ] I can explain why $NH_3$ is collected by downward displacement of air.\r\n- [ ] I can list all the conditions for Haber\'s process.\r\n- [ ] I can write the balanced equations for the lime water test.\r\n- [ ] I know the main uses of both gases.\r\n---\r\n## 🎊 CONCLUSION\r\nCarbon Dioxide and Ammonia are two gases with contrasting properties but equal importance in our world. From the fizz in your soda to the fertilizer that grows your food, their chemistry is at work all around us. Mastering their preparation and properties is a key step in understanding practical chemistry.\r\n**Key to Success:** Practice the Diagrams + Master the \'Give Reasons\' + Memorize the Reactions = Excellent Marks!', 1, '2025-07-25 01:11:38', '2025-09-16 15:20:38'),
(93, 11604, '# Blood Circulation in Human Body - Grade 10 (SEE) Science\r\n## Complete Chapter Notes with All Exercises - NEB Curriculum\r\n---\r\n## 🎯 Chapter Overview\r\n**Think of your body as a bustling city. The roads are your blood vessels, the vehicles are your blood cells, and the central transport hub is your heart.** This chapter, \"Blood Circulation in Human Body,\" explores this incredible transport system that keeps you alive. These notes will make understanding this complex network simple and fascinating.\r\n**This is a vital chapter in biology with high importance in the SEE exam, especially the diagram of the heart and the concept of double circulation.** We\'ll break down the components—blood, blood vessels, and the heart—and trace the journey of blood as it delivers oxygen and nutrients and removes waste. Every exercise from your textbook is solved here, with clear, easy-to-follow explanations.\r\n**Weightage:** 7-9 marks in SEE examination\r\n**Time Required:** 15-20 periods\r\n---\r\n## 📚 Learning Objectives\r\nAfter studying this chapter, you will be able to:\r\n- Identify the three main components of the circulatory system.\r\n- Describe the composition and functions of blood, including plasma and blood cells.\r\n- Differentiate between arteries, veins, and capillaries.\r\n- Draw a labeled diagram of the human heart and describe its structure.\r\n- Explain the mechanism of double circulation (pulmonary and systemic).\r\n- Understand concepts like heartbeat and blood pressure.\r\n- Identify the causes, symptoms, and preventive measures of some circulatory disorders.\r\n---\r\n##🩸 1. BLOOD: The Fluid of Life\r\n**Blood** is a vital red fluid connective tissue that circulates throughout our body. An average adult has about 5-6 litres of blood. It\'s composed of two main parts: Plasma and Blood Corpuscles.\r\n\r\n### A. Plasma (55% of Blood)\r\nPlasma is the pale-yellow, liquid matrix of the blood. It consists of about 90% water and 10% dissolved substances.\r\n- **Function:**\r\n  1.  **Transport:** Carries digested food, hormones, waste products (like urea), and proteins.\r\n  2.  **Regulation:** Helps in regulating body temperature.\r\n  3.  **Clotting:** Contains proteins like fibrinogen, which are essential for blood clotting.\r\n\r\n### B. Blood Corpuscles/Cells (45% of Blood)\r\nThese are the cells suspended in the plasma.\r\n\r\n| Cell Type | Other Name | Key Features | Main Function |\r\n|---|---|---|---|\r\n| **RBCs** | Erythrocytes | Biconcave discs, no nucleus at maturity, red due to **hemoglobin**. Most numerous blood cell. | Transport oxygen from lungs to body tissues. |\r\n| **WBCs** | Leucocytes | Irregular shape, have a nucleus, larger than RBCs. Can move like an amoeba. | **Body\'s defense system.** They engulf germs and produce antibodies to fight infections. |\r\n| **Platelets**| Thrombocytes| Tiny, irregular cell fragments, no nucleus. | Help in **blood clotting** at the site of an injury to prevent excessive bleeding. |\r\n\r\n\r\n---\r\n## 🛣️ 2. BLOOD VESSELS: The Body\'s Highway Network\r\nBlood vessels are a network of tubes that transport blood throughout the entire body.\r\n\r\n| Feature | Arteries | Veins | Capillaries |\r\n|---|---|---|---|\r\n| **Function** | Carry blood **AWAY** from the heart. | Carry blood **TOWARDS** the heart. | Connect arteries to veins; site of exchange. |\r\n| **Blood Type** | **Oxygenated** (except Pulmonary Artery). | **Deoxygenated** (except Pulmonary Veins). | Exchange of gases and nutrients occurs here. |\r\n| **Wall** | **Thick**, muscular, and elastic to withstand high pressure. | **Thin** and less muscular. | **Extremely thin** (one-cell thick) for easy diffusion. |\r\n| **Pressure** | Blood flows under **high pressure** and speed. | Blood flows under **low pressure** and speed. | Pressure is very low. |\r\n| **Valves** | Absent (pressure from the heart prevents backflow). | **Present** to prevent the backflow of blood. | Absent. |\r\n\r\n---\r\n## ❤️ 3. THE HEART: The Super Pump\r\nThe heart is a muscular organ, about the size of a fist, that pumps blood continuously. It has four chambers.\r\n**Analogy:** Think of the heart as a two-story house with two rooms on each floor. The upper floors are **Atria (Auricles)** and the lower floors are **Ventricles**.\r\n\r\n\r\n\r\n### Chambers and Valves\r\n- **Right Atrium (RA):** Receives deoxygenated blood from the body.\r\n- **Right Ventricle (RV):** Pumps deoxygenated blood to the lungs.\r\n- **Left Atrium (LA):** Receives oxygenated blood from the lungs.\r\n- **Left Ventricle (LV):** Pumps oxygenated blood to the entire body. **(Has the thickest wall)**.\r\n\r\n- **Valves:** These are like one-way doors that prevent blood from flowing backward.\r\n  - **Tricuspid Valve:** Between the right atrium and right ventricle.\r\n  - **Bicuspid (Mitral) Valve:** Between the left atrium and left ventricle.\r\n---\r\n## 🔄 4. DOUBLE CIRCULATION: The Two-Circuit Journey\r\nIn humans, blood passes through the heart **twice** to make one complete circuit. This efficient system is called **double circulation**. It consists of two loops:\r\n\r\n### A. Pulmonary Circulation (The \"Lungs\" Loop)\r\nThis circuit carries deoxygenated blood from the heart to the lungs and brings oxygenated blood back.\r\n**Path:** **Right Ventricle** $\\rightarrow$ Pulmonary Artery (deoxygenated blood) $\\rightarrow$ **Lungs** (blood gets oxygenated) $\\rightarrow$ Pulmonary Veins (oxygenated blood) $\\rightarrow$ **Left Atrium**.\r\n\r\n### B. Systemic Circulation (The \"Body\" Loop)\r\nThis circuit carries oxygenated blood from the heart to all body parts and brings deoxygenated blood back.\r\n**Path:** **Left Ventricle** $\\rightarrow$ Aorta (oxygenated blood) $\\rightarrow$ **All Body Parts** (oxygen is delivered) $\\rightarrow$ Vena Cava (deoxygenated blood) $\\rightarrow$ **Right Atrium**.\r\n\r\n\r\n\r\n---\r\n## 🩺 5. HEARTBEAT, BLOOD PRESSURE & DISORDERS\r\n\r\n- **Heartbeat:** One complete contraction (systole) and relaxation (diastole) of the heart muscle. The normal rate for a resting adult is about **72 beats per minute**. This rate increases during exercise, fear, or excitement.\r\n- **High Blood Pressure (Hypertension):** A condition where the force of the blood against the artery walls is too high.\r\n  - **Causes:** Smoking, excessive alcohol consumption, stress, obesity, lack of exercise.\r\n  - **Prevention:** Maintaining a healthy weight, regular exercise, balanced diet, avoiding smoking.\r\n- **Uric Acid:** High levels can cause joint pain (gout). Prevention includes drinking plenty of water and consuming dairy products.\r\n- **Diabetes:** A condition affecting blood sugar levels. Symptoms include frequent urination and slow healing of wounds.\r\n\r\n---\r\n## 📋 6. COMPLETE EXERCISE SOLUTIONS\r\n\r\n### **1. Differentiate Between:**\r\n**a. Artery and Vein**\r\n| Artery | Vein |\r\n|---|---|\r\n| Carries blood **away** from the heart. | Carries blood **towards** the heart. |\r\n| Has **thick**, muscular, and elastic walls. | Has **thin**, less muscular walls. |\r\n| Carries oxygenated blood (except pulmonary artery). | Carries deoxygenated blood (except pulmonary vein). |\r\n| Blood pressure is high. | Blood pressure is low. |\r\n| Valves are absent. | Valves are present to prevent backflow. |\r\n\r\n**b. RBCs and WBCs**\r\n| RBCs (Red Blood Corpuscles) | WBCs (White Blood Corpuscles) |\r\n|---|---|\r\n| Are biconcave and have no nucleus. | Are irregular in shape and have a nucleus. |\r\n| Contain hemoglobin and are red. | Do not contain hemoglobin and are colorless. |\r\n| Function is to transport oxygen. | Function is to protect the body from diseases. |\r\n| They are more numerous. | They are less numerous (but increase during infection). |\r\n\r\n**c. Auricles and Ventricles**\r\n| Auricles (Atria) | Ventricles |\r\n|---|---|\r\n| The two **upper** chambers of the heart. | The two **lower** chambers of the heart. |\r\n| Have **thin** muscular walls. | Have **thick** muscular walls (especially the left). |\r\n| They **receive** blood from the body and lungs. | They **pump** blood to the lungs and body. |\r\n\r\n### **2. Give Reasons:**\r\n**a. The wall of the left ventricle is thicker than the right ventricle.**\r\n**Answer:** The left ventricle has to pump oxygenated blood to all parts of the body, which requires a much greater force and higher pressure. The right ventricle only has to pump deoxygenated blood to the nearby lungs, which requires less force. Therefore, the left ventricle has a thicker, more muscular wall.\r\n\r\n**b. Blood is red in colour.**\r\n**Answer:** Blood is red due to the presence of a pigment called **hemoglobin** in the Red Blood Cells (RBCs). Hemoglobin contains iron, which binds with oxygen and gives blood its characteristic red colour.\r\n\r\n**c. Arteries have thick and elastic walls.**\r\n**Answer:** Arteries receive blood directly from the heart\'s powerful pumping action. Their thick, muscular, and elastic walls are necessary to withstand the **high pressure** of the blood flow without bursting.\r\n\r\n**d. The number of WBCs in the blood increases during an infection.**\r\n**Answer:** WBCs are the \"soldiers\" of the body\'s immune system. When the body is attacked by pathogens like bacteria or viruses, it produces more WBCs to fight off the infection and destroy the invaders.\r\n\r\n**e. Donated blood is mixed with sodium citrate.**\r\n**Answer:** Sodium citrate is an **anticoagulant**. It prevents the blood from clotting by binding with calcium ions, which are essential for the clotting process. This keeps the blood in a liquid state and suitable for storage and transfusion.\r\n\r\n### **3. Answer the following questions:**\r\n**a. What is the importance of blood circulation?**\r\n**Answer:** Blood circulation is vital because it transports oxygen and nutrients to all body cells, removes waste products like carbon dioxide, helps regulate body temperature, and circulates WBCs and antibodies to fight diseases.\r\n\r\n**b. What exchange takes place between blood capillaries and tissues?**\r\n**Answer:** In the capillaries, oxygen and nutrients diffuse from the blood into the body tissues. At the same time, carbon dioxide and other waste products diffuse from the tissues into the blood to be carried away.\r\n\r\n---\r\n## ✅ 7. CHAPTER CHECKLIST & EXAM TIPS\r\n**Exam Hotspots 🔥:**\r\n-   **Diagram of the Heart:** Practice drawing a neat, well-labeled diagram of the human heart. This is a very common question.\r\n-   **Double Circulation:** Be able to draw a flowchart and explain the paths of both pulmonary and systemic circulation.\r\n-   **Differences:** The difference between arteries and veins is a classic and frequently asked question.\r\n-   **Give Reasons:** The reasons for the thick wall of the left ventricle and the thick walls of arteries are very important.\r\n\r\n**Your Pre-Exam Checklist:**\r\n- [ ] I can draw and label the four chambers and main vessels of the human heart.\r\n- [ ] I can differentiate between an artery and a vein based on 3-4 points.\r\n- [ ] I can describe the function of RBCs, WBCs, and platelets.\r\n- [ ] I can explain the path of blood in both pulmonary and systemic circulation.\r\n- [ ] I can explain why the left ventricle wall is the thickest.\r\n---\r\n## 🎊 CONCLUSION\r\nThe human circulatory system is a masterpiece of engineering, working tirelessly every second of your life. Understanding how this system functions not only helps in your exams but also empowers you to appreciate your own body and make healthier life choices.\r\n**Key to Success:** Master the Heart Diagram + Trace the Blood Flow + Understand the \"Why\" Questions = A Healthy Score!', 1, '2025-07-25 01:11:38', '2025-09-16 15:20:38'),
(94, 11601, '# Human Nervous & Glandular Systems - Grade 10 (SEE) Science\r\n## Complete Chapter Notes with All Exercises - NEB Curriculum\r\n---\r\n## 🎯 Chapter Overview\r\n**Think of your body\'s coordination like a high-tech command center.** The **Nervous System** is the super-fast internet, sending electrical signals in milliseconds, while the **Glandular (Endocrine) System** is the reliable postal service, sending chemical messages (hormones) through the bloodstream. Together, they control everything you think, feel, and do.\r\n**This chapter is a fascinating journey into the body\'s control systems and is crucial for the SEE exam.** We\'ll explore the structure of the brain, spinal cord, and neurons, understand lightning-fast reflex actions, and learn about the powerful hormones that regulate our growth, mood, and metabolism. Every exercise from your textbook is solved here with clear, detailed explanations.\r\n**Weightage:** 7-9 marks in SEE examination\r\n**Time Required:** 15-20 periods\r\n---\r\n## 📚 Learning Objectives\r\nAfter studying this chapter, you will be able to:\r\n- Differentiate between the nervous and glandular systems.\r\n- Draw a labeled diagram of a neuron and describe its structure.\r\n- Describe the structure and functions of the main parts of the human brain.\r\n- Explain the mechanism of reflex action with a reflex arc.\r\n- Differentiate between endocrine and exocrine glands.\r\n- State the location, hormones, and functions of major endocrine glands.\r\n- Understand the causes and effects of hormonal imbalances.\r\n---\r\n## 🧠 Part A: The Nervous System (The High-Speed Network)\r\nThe nervous system is the body\'s primary control and communication network. It receives information from the environment (**stimulus**) and generates a suitable response (**reaction**).\r\n-   **Stimulus:** Any change in the internal or external environment that causes a response in an organism. (e.g., touching a hot object).\r\n-   **Reaction (Response):** The action performed by the organism due to a stimulus. (e.g., pulling your hand away).\r\n\r\n### 1. The Neuron: The Basic Unit\r\nA **neuron** (or nerve cell) is the structural and functional unit of the nervous system. Its job is to transmit nerve impulses (electrical signals).\r\n\r\n**Structure of a Neuron:**\r\n1.  **Cell Body (Cyton):** The main part containing the nucleus.\r\n2.  **Dendrites:** Short, branched fibers that **receive** nerve impulses from other neurons and carry them **towards** the cell body.\r\n3.  **Axon:** A single, long fiber that carries nerve impulses **away** from the cell body to other neurons or muscles.\r\n\r\n\r\n\r\n[Image of the structure of a neuron]\r\n\r\n\r\n### 2. Central Nervous System (CNS): The Central Processor\r\nThe CNS is the main control center, consisting of the brain and the spinal cord.\r\n\r\n#### A. The Brain\r\nThe brain is the command center of the body, protected within the **cranial cavity** of the skull. It is covered by three protective membranes called **meninges** (Dura mater, Arachnoid mater, and Pia mater).\r\n\r\n| Part | Location | Key Functions |\r\n|---|---|---|\r\n| **Cerebrum** | Largest, uppermost part of the brain. | • Center of intelligence, memory, emotion, logic, and consciousness.<br>• Controls all voluntary actions (walking, talking, etc.). |\r\n| **Cerebellum** | Below the cerebrum, at the back of the head. | • Controls body balance and posture.<br>• Coordinates and smooths out voluntary movements. |\r\n| **Medulla Oblongata** | Lowest part of the brain, connecting to the spinal cord. | • Controls vital involuntary actions like heartbeat, breathing rate, and blood pressure.<br>• **Injury here causes instant death.** |\r\n\r\n#### B. The Spinal Cord\r\nThe spinal cord is a long, cylindrical bundle of nerve tissue that extends from the medulla oblongata down the back, protected by the vertebral column.\r\n-   **Functions:**\r\n    1.  Acts as a pathway for nerve signals between the brain and the rest of the body.\r\n    2.  It is the control center for **reflex actions**.\r\n\r\n### 3. Reflex Action and Reflex Arc\r\n-   **Reflex Action:** A sudden, rapid, and involuntary response to a stimulus, controlled by the spinal cord. It is a protective mechanism.\r\n    -   **Example:** Immediately withdrawing your hand when you touch a pin. You pull your hand back before your brain even registers the pain.\r\n-   **Reflex Arc:** The neural pathway that a nerve impulse follows during a reflex action.\r\n    **Path:** Receptor (skin) $\\rightarrow$ Sensory Neuron $\\rightarrow$ Spinal Cord $\\rightarrow$ Motor Neuron $\\rightarrow$ Effector (muscle).\r\n\r\n\r\n\r\n[Image of a reflex arc diagram]\r\n\r\n\r\n---\r\n## 🧪 Part B: The Glandular System (The Chemical Mail)\r\nThe glandular or endocrine system consists of glands that produce chemical messengers called **hormones**. Hormones travel through the bloodstream to target cells and regulate various bodily functions like growth, metabolism, and mood.\r\n\r\n### 1. Types of Glands\r\n\r\n| Feature | Endocrine Glands | Exocrine Glands |\r\n|---|---|---|\r\n| **Ducts** | **Ductless**; they release hormones directly into the bloodstream. | **Have ducts** (tubes) to carry their secretions to a specific location. |\r\n| **Secretion** | Hormones (e.g., Insulin, Thyroxine). | Enzymes, sweat, saliva, tears, mucus. |\r\n| **Example** | Pituitary gland, Thyroid gland, Adrenal gland. | Salivary glands, Sweat glands, Liver. |\r\n\r\n### 2. Major Endocrine Glands and Their Hormones\r\n\r\n| Gland | Location | Hormone(s) | Key Function(s) | Effects of Imbalance |\r\n|---|---|---|---|---|\r\n| **Pituitary Gland** | Base of the brain. | Growth Hormone (GH), TSH | **Master Gland**: Controls other glands; regulates body growth. | **Hypo**secretion: **Dwarfism**. **Hyper**secretion: **Gigantism**. |\r\n| **Thyroid Gland** | Neck (in front of trachea). | Thyroxine | Controls the body\'s metabolic rate. Requires **iodine** to function. | **Hypo**secretion (due to Iodine deficiency): **Goitre**. |\r\n| **Adrenal Gland**| On top of kidneys. | Adrenaline | **Emergency Hormone**: Prepares the body for \"Fight or Flight\" response. | |\r\n| **Pancreas** | Behind the stomach. | Insulin & Glucagon | Regulates blood glucose (sugar) level. | **Hypo**secretion of Insulin: **Diabetes Mellitus**. |\r\n| **Gonads (Testes/Ovaries)** | Pelvic region. | Testosterone (males), Estrogen (females) | Control development of secondary sexual characteristics. | |\r\n\r\n### 3. Heterocrine (Mixed) Gland: The Pancreas\r\nThe pancreas is called a **mixed or heterocrine gland** because it has both endocrine and exocrine functions.\r\n-   **Endocrine function:** Produces hormones (insulin and glucagon) and releases them into the blood.\r\n-   **Exocrine function:** Produces pancreatic juice (digestive enzymes) and releases it into the small intestine through a duct.\r\n\r\n---\r\n## 📋 4. COMPLETE EXERCISE SOLUTIONS\r\n\r\n### **1. Differentiate Between:**\r\n**a. Cerebrum and Cerebellum**\r\n| Cerebrum | Cerebellum |\r\n|---|---|\r\n| The largest part of the brain. | Smaller than the cerebrum, located at the back. |\r\n| It is the center of intelligence, memory, and voluntary actions. | It maintains body balance, posture, and coordinates movements. |\r\n| Part of the forebrain. | Part of the hindbrain. |\r\n\r\n**b. Sensory Nerves and Motor Nerves**\r\n| Sensory Nerves (Afferent) | Motor Nerves (Efferent) |\r\n|---|---|\r\n| Carry nerve impulses from sense organs **to** the CNS (brain/spinal cord). | Carry nerve impulses **from** the CNS to muscles or glands (effectors). |\r\n| They inform the CNS about stimuli. | They carry out the commands from the CNS. |\r\n\r\n**c. Sympathetic and Parasympathetic ANS**\r\n| Sympathetic ANS | Parasympathetic ANS |\r\n|---|---|\r\n| Prepares the body for a **\"fight or flight\"** response in emergencies. | Brings the body back to a calm **\"rest and digest\"** state. |\r\n| Increases heart rate, breathing rate, blood pressure. | Decreases heart rate, breathing rate, blood pressure. |\r\n\r\n### **2. Give Reasons:**\r\n**a. The pituitary gland is called the master gland.**\r\n**Answer:** Because the pituitary gland produces several hormones (like TSH, ACTH) that control and regulate the functioning of many other endocrine glands, such as the thyroid and adrenal glands.\r\n\r\n**b. The adrenal gland is also called an emergency gland.**\r\n**Answer:** Because it secretes the hormone **adrenaline** during conditions of stress, fear, or excitement. Adrenaline prepares the body for a \"fight or flight\" response by increasing heart rate, blood pressure, and glucose levels, providing a burst of energy to face the emergency.\r\n\r\n**c. A person dies instantly when the medulla oblongata is injured.**\r\n**Answer:** The medulla oblongata controls vital, involuntary life functions such as **heartbeat, breathing, and blood pressure**. Any severe injury to it, like in the case of hanging, disrupts these functions, leading to immediate cessation of breathing and heartbeat, causing instant death.\r\n\r\n**d. The pancreas is a mixed gland.**\r\n**Answer:** Because it performs both endocrine and exocrine functions. As an endocrine gland, it secretes hormones (insulin, glucagon) directly into the blood. As an exocrine gland, it secretes pancreatic juice into the duodenum through a duct.\r\n\r\n**e. Hormones are called chemical messengers.**\r\n**Answer:** Hormones are chemical substances produced by endocrine glands that are transported by the blood to target organs or cells elsewhere in the body, where they deliver a \"message\" to regulate a specific function, like growth or metabolism.\r\n\r\n### **3. Answer the following questions:**\r\n**a. Why do animals respond more quickly than plants?**\r\n**Answer:** Animals respond more quickly because they possess a well-developed nervous system for rapid electrical signal transmission and an endocrine system for hormonal control. Plants lack these specialized systems and respond much more slowly through chemical changes.\r\n\r\n**b. In the given diagram of the endocrine system, identify glands B, D, and F and write one function of each.**\r\n\r\n\r\n[Image of the human endocrine system]\r\n\r\n**Ans:**\r\n- **B (Thyroid Gland):** Its function is to secrete thyroxine, which controls the body\'s overall metabolic rate.\r\n- **D (Pancreas):** Its function is to secrete insulin and glucagon to regulate blood sugar levels.\r\n- **F (Testes - in males):** Its function is to produce testosterone, which is responsible for male secondary sexual characteristics.\r\n\r\n---\r\n## ✅ 5. CHAPTER CHECKLIST & EXAM TIPS\r\n**Exam Hotspots 🔥:**\r\n-   **Diagrams:** The diagram of a neuron is very frequently asked. The diagram of the brain is also important.\r\n-   **Brain Functions:** Be able to state at least two functions for the cerebrum, cerebellum, and medulla oblongata.\r\n-   **Reflex Arc:** Understand and be able to describe the path of a reflex arc.\r\n-   **Glands & Hormones:** The location, hormone, and function of the Pituitary, Thyroid, and Pancreas are high-priority topics.\r\n-   **Give Reasons:** The reasons why the pituitary is the \'master gland\', the adrenal is the \'emergency gland\', and the pancreas is a \'mixed gland\' are classic exam questions.\r\n\r\n**Your Pre-Exam Checklist:**\r\n- [ ] I can draw and label a neuron.\r\n- [ ] I can state the main functions of the cerebrum, cerebellum, and medulla oblongata.\r\n- [ ] I can explain what a reflex action is and trace the path of a reflex arc.\r\n- [ ] I can differentiate between endocrine and exocrine glands.\r\n- [ ] I can name the hormone responsible for goitre and diabetes.\r\n- [ ] I can explain why the pituitary is called the \"Master Gland\".\r\n---\r\n## 🎊 CONCLUSION\r\nThe nervous and glandular systems are the master coordinators of our body, working in perfect harmony to keep us alive, responsive, and balanced. Understanding how they operate is key to appreciating the complexity and wonder of the human body.\r\n**Key to Success:** Master the Diagrams + Learn the Functions by Heart + Understand the \"Why\" Questions = A Top Score!', 1, '2025-07-25 01:11:38', '2025-09-16 15:20:38');
INSERT INTO `course_notes_content` (`id`, `topic_id`, `content`, `markdown_format`, `created_at`, `updated_at`) VALUES
(95, 11606, '# Human Nervous & Glandular Systems - Grade 10 (SEE) Science\r\n## Complete Chapter Notes with All Exercises - NEB Curriculum\r\n---\r\n## 🎯 Chapter Overview\r\n**Think of your body\'s coordination like a high-tech command center.** The **Nervous System** is the super-fast internet, sending electrical signals in milliseconds, while the **Glandular (Endocrine) System** is the reliable postal service, sending chemical messages (hormones) through the bloodstream. Together, they control everything you think, feel, and do.\r\n**This chapter is a fascinating journey into the body\'s control systems and is crucial for the SEE exam.** We\'ll explore the structure of the brain, spinal cord, and neurons, understand lightning-fast reflex actions, and learn about the powerful hormones that regulate our growth, mood, and metabolism. Every exercise from your textbook is solved here with clear, detailed explanations.\r\n**Weightage:** 7-9 marks in SEE examination\r\n**Time Required:** 15-20 periods\r\n---\r\n## 📚 Learning Objectives\r\nAfter studying this chapter, you will be able to:\r\n- Differentiate between the nervous and glandular systems.\r\n- Draw a labeled diagram of a neuron and describe its structure.\r\n- Describe the structure and functions of the main parts of the human brain.\r\n- Explain the mechanism of reflex action with a reflex arc.\r\n- Differentiate between endocrine and exocrine glands.\r\n- State the location, hormones, and functions of major endocrine glands.\r\n- Understand the causes and effects of hormonal imbalances.\r\n---\r\n## 🧠 Part A: The Nervous System (The High-Speed Network)\r\nThe nervous system is the body\'s primary control and communication network. It receives information from the environment (**stimulus**) and generates a suitable response (**reaction**). Animals respond more quickly than plants because they possess this highly developed system.\r\n-   **Stimulus:** Any change in the internal or external environment that causes a response in an organism. (e.g., a rabbit seeing a predator).\r\n-   **Reaction (Response):** The action performed by the organism due to a stimulus. (e.g., the rabbit running away).\r\n\r\n### 1. The Neuron: The Basic Unit\r\nA **neuron** (or nerve cell) is the structural and functional unit of the nervous system. Its job is to transmit nerve impulses (electrical signals).\r\n\r\n\r\n\r\n[Image of the structure of a neuron]\r\n\r\n\r\n**Structure of a Neuron:**\r\n1.  **Cell Body (Cyton):** The main part containing the nucleus and cytoplasm. It controls the neuron\'s activities.\r\n2.  **Dendrites:** Short, highly branched fibers that **receive** nerve impulses from other neurons and carry them **towards** the cell body.\r\n3.  **Axon:** A single, long, tube-like fiber that carries nerve impulses **away** from the cell body to other neurons or muscles.\r\n\r\n### 2. Central Nervous System (CNS): The Central Processor\r\nThe CNS is the main control center, consisting of the brain and the spinal cord.\r\n\r\n#### A. The Brain\r\nThe brain is the command center of the body, protected within the **cranial cavity** of the skull. It is covered by three protective membranes called **meninges** (Dura mater, Arachnoid mater, and Pia mater).\r\n\r\n| Part | Location | Key Functions |\r\n|---|---|---|\r\n| **Cerebrum** | Largest, uppermost part of the brain, with a folded surface. | • Center of intelligence, memory, emotion, logic, and consciousness.<br>• Controls all voluntary actions (walking, talking, thinking). |\r\n| **Cerebellum** | Below the cerebrum, at the back of the head. | • Controls body balance and posture.<br>• Coordinates and makes voluntary movements smooth and precise. |\r\n| **Medulla Oblongata** | Lowest part of the brain, connecting to the spinal cord. | • Controls vital involuntary actions like heartbeat, breathing rate, and blood pressure.<br>• **Injury here causes instant death.** |\r\n\r\n#### B. The Spinal Cord\r\nThe spinal cord is a long, soft, whitish cord of nerve tissue that extends from the medulla oblongata down the back, protected by the vertebral column.\r\n-   **Functions:**\r\n    1.  Acts as a pathway for nerve signals between the brain and the rest of the body.\r\n    2.  It is the control center for **reflex actions**.\r\n-   **Structure:** It has grey matter at its core (H-shaped) and white matter on the outside, which is the opposite of the brain\'s arrangement.\r\n\r\n### 3. Reflex Action and Reflex Arc\r\n-   **Reflex Action:** A sudden, rapid, and involuntary response to a stimulus, controlled by the spinal cord. It is a protective mechanism.\r\n    -   **Example:** Immediately withdrawing your hand or leg when you accidentally touch a hot or sharp object.\r\n-   **Reflex Arc:** The neural pathway that a nerve impulse follows during a reflex action.\r\n    **Path:** Receptor (in skin) $\\rightarrow$ Sensory Neuron $\\rightarrow$ Spinal Cord $\\rightarrow$ Motor Neuron $\\rightarrow$ Effector (muscle).\r\n\r\n\r\n\r\n[Image of a reflex arc diagram]\r\n\r\n\r\n---\r\n## 🧪 Part B: The Glandular System (The Chemical Mail)\r\nThe glandular or endocrine system consists of glands that produce chemical messengers called **hormones**. Hormones travel through the bloodstream to target cells and regulate various bodily functions like growth, metabolism, and mood.\r\n\r\n### 1. Types of Glands\r\n\r\n| Feature | Endocrine Glands | Exocrine Glands |\r\n|---|---|---|\r\n| **Ducts** | **Ductless**; they release hormones directly into the bloodstream. | **Have ducts** (tubes) to carry their secretions to a specific location. |\r\n| **Secretion** | Hormones (e.g., Insulin, Thyroxine). | Enzymes, sweat, saliva, tears, mucus. |\r\n| **Example** | Pituitary gland, Thyroid gland, Adrenal gland. | Salivary glands, Sweat glands, Liver. |\r\n\r\n### 2. Major Endocrine Glands and Their Hormones\r\n\r\n\r\n\r\n| Gland | Location | Hormone(s) | Key Function(s) | Effects of Imbalance |\r\n|---|---|---|---|---|\r\n| **Pituitary Gland** | Base of the brain. | Growth Hormone (GH), TSH, FSH, ADH, etc. | **Master Gland**: Controls other glands; regulates body growth. | **Hypo**secretion of GH: **Dwarfism**. **Hyper**secretion of GH: **Gigantism**. |\r\n| **Thyroid Gland** | Neck (in front of trachea). | Thyroxine | Controls the body\'s metabolic rate. Requires **iodine** to function. | **Hypo**secretion (due to Iodine deficiency): **Goitre**. |\r\n| **Adrenal Gland**| On top of kidneys. | Adrenaline | **Emergency Hormone**: Prepares the body for \"Fight or Flight\" response. | |\r\n| **Pancreas** | Behind the stomach. | Insulin & Glucagon | Regulates blood glucose (sugar) level. | **Hypo**secretion of Insulin: **Diabetes Mellitus**. |\r\n| **Gonads (Testes/Ovaries)** | Pelvic region. | Testosterone (males), Estrogen (females) | Control development of secondary sexual characteristics. | |\r\n\r\n### 3. Heterocrine (Mixed) Gland: The Pancreas\r\nThe pancreas is called a **mixed or heterocrine gland** because it has both endocrine and exocrine functions.\r\n-   **Endocrine function:** Produces hormones (insulin and glucagon) and releases them into the blood.\r\n-   **Exocrine function:** Produces pancreatic juice (digestive enzymes) and releases it into the small intestine through a duct.\r\n\r\n---\r\n## 📋 4. COMPLETE EXERCISE SOLUTIONS\r\n\r\n### **1. Differentiate Between:**\r\n**a. Dendrites and Axon**\r\n| Dendrites | Axon |\r\n|---|---|\r\n| Short and highly branched extensions. | A single, long, tube-like fiber. |\r\n| Carry impulses **towards** the cell body. | Carries impulses **away** from the cell body. |\r\n| A neuron has many dendrites. | A neuron has only one axon. |\r\n\r\n**b. Cerebrum and Cerebellum**\r\n| Cerebrum | Cerebellum |\r\n|---|---|\r\n| The largest part of the brain. | Smaller than the cerebrum, located at the back. |\r\n| It is the center of intelligence, memory, and voluntary actions. | It maintains body balance, posture, and coordinates movements. |\r\n\r\n**c. Endocrine and Exocrine Glands**\r\n| Endocrine Glands | Exocrine Glands |\r\n|---|---|\r\n| They are **ductless** glands. | They are **ducted** glands. |\r\n| They secrete **hormones** directly into the bloodstream. | They secrete juices like saliva, tears, and enzymes through ducts. |\r\n\r\n### **2. Give Reasons:**\r\n**a. The pituitary gland is called the master gland.**\r\n**Answer:** Because the pituitary gland produces several hormones (like TSH, ACTH) that control and regulate the functioning of many other endocrine glands, such as the thyroid and adrenal glands, acting as a \"master\" controller.\r\n\r\n**b. The adrenal gland is also called an emergency gland.**\r\n**Answer:** Because it secretes the hormone **adrenaline** during conditions of stress, fear, or excitement. Adrenaline prepares the body for a \"fight or flight\" response by increasing heart rate, blood pressure, and glucose levels, providing a burst of energy to face the emergency.\r\n\r\n**c. A person dies instantly when hanged.**\r\n**Answer:** Hanging causes severe injury or fracture to the vertebrae in the neck, which in turn damages the **medulla oblongata**. Since the medulla oblongata controls vital involuntary functions like heartbeat and breathing, its damage leads to immediate cessation of these functions, causing instant death.\r\n\r\n**d. The cerebrum\'s surface is grey while the spinal cord\'s surface is white.**\r\n**Answer:** This is due to the arrangement of neurons. **Grey matter** is primarily composed of the cell bodies of neurons, while **white matter** is composed of their axons. In the cerebrum, the cell bodies are on the outer surface (cortex). In the spinal cord, the axons form the outer surface, while the cell bodies are in the core.\r\n\r\n### **3. Answer the following questions:**\r\n**a. Describe reflex action with a clear example.**\r\n**Answer:** Reflex action is a rapid, involuntary, and protective response to a stimulus that is controlled by the spinal cord. For example, if we accidentally step on a sharp pin, our sensory receptors send a signal via a sensory nerve to the spinal cord. The spinal cord immediately sends a command via a motor nerve to the leg muscles to withdraw the foot. This happens almost instantly, even before the brain consciously registers the pain.\r\n\r\n**b. Why is the pancreas called a heterocrine gland? List the functions of insulin and glucagon.**\r\n**Answer:** The pancreas is called a heterocrine (mixed) gland because it has both endocrine and exocrine parts. Its endocrine part secretes hormones (insulin and glucagon) into the blood, and its exocrine part secretes pancreatic juice through a duct.\r\n-   **Function of Insulin:** To **decrease** the glucose level in the blood by helping cells absorb it.\r\n-   **Function of Glucagon:** To **increase** the glucose level in the blood by stimulating the liver to release stored glucose.\r\n\r\n---\r\n## ✅ 5. CHAPTER CHECKLIST & EXAM TIPS\r\n**Exam Hotspots 🔥:**\r\n-   **Diagrams:** The diagram of a neuron is very frequently asked. The diagram of the brain is also important.\r\n-   **Brain Functions:** Be able to state at least two functions for the cerebrum, cerebellum, and medulla oblongata.\r\n-   **Reflex Arc:** Understand and be able to describe the path of a reflex arc.\r\n-   **Glands & Hormones:** The location, hormone, and function of the Pituitary, Thyroid, and Pancreas are high-priority topics.\r\n-   **Give Reasons:** The reasons why the pituitary is the \'master gland\', the adrenal is the \'emergency gland\', and the pancreas is a \'mixed gland\' are classic exam questions.\r\n\r\n**Your Pre-Exam Checklist:**\r\n- [ ] I can draw and label a neuron.\r\n- [ ] I can state the main functions of the cerebrum, cerebellum, and medulla oblongata.\r\n- [ ] I can explain what a reflex action is and trace the path of a reflex arc.\r\n- [ ] I can differentiate between endocrine and exocrine glands.\r\n- [ ] I can name the hormone responsible for goitre and diabetes.\r\n- [ ] I can explain why the pituitary is called the \"Master Gland\".\r\n---\r\n## 🎊 CONCLUSION\r\nThe nervous and glandular systems are the master coordinators of our body, working in perfect harmony to keep us alive, responsive, and balanced. Understanding how they operate is key to appreciating the complexity and wonder of the human body.\r\n**Key to Success:** Master the Diagrams + Learn the Functions by Heart + Understand the \"Why\" Questions = A Top Score!', 1, '2025-07-25 01:11:38', '2025-09-16 15:20:38'),
(96, 13205, '# Contemporary Technology - Grade 10 Science/Computer Notes\r\n## Complete Chapter Notes with All Exercises - NEB Curriculum\r\n---\r\n## 🎯 Chapter Overview\r\n**Welcome to the future, which is happening right now!** This chapter, \"Contemporary Technology,\" is your guide to the most exciting and transformative technologies shaping our world: **Cloud Computing, Artificial Intelligence (AI), Virtual Reality (VR), and more.** These aren\'t just buzzwords; they are the tools building our modern society.\r\n**This is a high-scoring and fascinating chapter that connects directly to the gadgets and services you use every day.** We\'ll demystify these complex topics with simple analogies and clear examples. Every exercise from your textbook is solved here, ensuring you have a solid grasp of the technologies that define our era.\r\n**Weightage:** 6-8 marks in SEE examination\r\n**Time Required:** 12-15 periods\r\n---\r\n## 📚 Learning Objectives\r\nAfter studying this chapter, you will be able to:\r\n- Define and explain Cloud Computing, AI, VR, E-Governance, Mobile Computing, and IoT.\r\n- Differentiate between various types of cloud computing services (IaaS, PaaS, SaaS).\r\n- List the applications, advantages, and disadvantages of these modern technologies.\r\n- Understand the different models of E-Governance (G2C, G2B, etc.).\r\n- Identify key technical terms and acronyms related to contemporary technology.\r\n---\r\n## ☁️ 1. Cloud Computing: Your Data in the Sky\r\n**Cloud Computing** is the delivery of on-demand computing services—including servers, storage, databases, and software—over the Internet (\"the cloud\").\r\n**Analogy:** Instead of storing movies on a DVD (your local hardware), you stream them from Netflix (the cloud). You can access Netflix from any device, anywhere with an internet connection. That\'s cloud computing!\r\n\r\n\r\n\r\n[Image of a diagram showing cloud computing]\r\n\r\n\r\n### Types of Cloud Deployment\r\n| Public Cloud | Private Cloud |\r\n|---|---|\r\n| Services are available to the general public over the internet. | The cloud infrastructure is owned by and operated for a single organization. |\r\n| The cloud service provider (e.g., Google, Amazon) manages the resources. | The organization itself is responsible for managing and maintaining the resources. |\r\n\r\n### Cloud Service Models (The \"Pizza as a Service\" Analogy 🍕)\r\n\r\n| Model | What it Provides | Analogy | Examples |\r\n|---|---|---|---|\r\n| **IaaS** (Infrastructure as a Service) | Basic building blocks: virtual servers, storage, networking. | **Making pizza at home:** You buy the raw ingredients (flour, sauce) and use your own oven. | Amazon Web Services (AWS), Microsoft Azure. |\r\n| **PaaS** (Platform as a Service) | A platform for developers to build, test, and deploy applications. | **Pizza delivery:** A pizza place sends you the base and toppings; you just bake it in your oven. | Google App Engine, Heroku. |\r\n| **SaaS** (Software as a Service) | Ready-to-use software applications accessed over the internet. | **Dining out:** You go to a restaurant and get a fully cooked pizza. You just eat it. | **Google Docs, Gmail, Spotify, Netflix.** |\r\n\r\n### Uses, Advantages & Disadvantages\r\n- **Uses:** Data storage and backup, hosting websites, streaming audio/video, on-demand software.\r\n- **Advantages:**\r\n    - **Accessibility:** Access your files and applications from any location with internet.\r\n    - **Cost-Effective:** Reduces the need to buy and maintain expensive hardware.\r\n- **Disadvantages:**\r\n    - **Internet Dependency:** Requires a constant and reliable internet connection.\r\n    - **Security Concerns:** Data security and privacy are potential risks.\r\n\r\n---\r\n## 🤖 2. Artificial Intelligence (AI): Thinking Machines\r\n**Artificial Intelligence (AI)** is a branch of computer science that aims to create machines capable of performing tasks that typically require human intelligence, such as learning, reasoning, problem-solving, and understanding language.\r\n\r\n- **Applications:**\r\n  - **Healthcare:** AI helps in diagnosing diseases and personalizing treatments.\r\n  - **Gaming:** Creates realistic and intelligent non-player characters (NPCs).\r\n  - **Virtual Assistants:** **Siri, Google Assistant, and Alexa** use AI to understand and respond to voice commands.\r\n  - **Self-Driving Cars:** AI is the \"brain\" that allows cars to navigate roads.\r\n- **Advantages:**\r\n  - Reduces human error and effort.\r\n  - Can perform dangerous and repetitive tasks.\r\n  - Operates 24/7 without fatigue.\r\n  - Thinks logically and processes vast amounts of data quickly.\r\n\r\n---\r\n## 🕶️ 3. Virtual Reality (VR): Entering Digital Worlds\r\n**Virtual Reality (VR)** is an artificial, computer-generated simulation of a 3D environment that can be interacted with in a seemingly real way. Users typically wear a headset that replaces their real-world view with the digital world.\r\n- **Key Goal:** To create a sense of **immersion** or \"presence\" within the virtual environment.\r\n- **Areas of Use:**\r\n  - **Education & Training:** Simulating complex surgeries for medical students or flight training for pilots.\r\n  - **Business:** Virtual property tours, product design, and remote collaboration.\r\n  - **Gaming & Entertainment:** Creating immersive game worlds and experiences.\r\n\r\n---\r\n## 🏛️ 4. E-Governance: Digital Government Services\r\n**E-Governance** is the application of Information and Communication Technology (ICT) to deliver government services, exchange information, and interact with citizens, businesses, and other government agencies.\r\n\r\n### Types of E-Governance Interactions\r\n- **G2C (Government to Citizen):** Services provided by the government directly to citizens. (e.g., online tax payment, applying for a passport, viewing land records).\r\n- **G2B (Government to Business):** Services and information provided to the business community. (e.g., online business registration, e-procurement).\r\n- **G2G (Government to Government):** Information sharing and coordination between different government departments or agencies.\r\n- **G2E (Government to Employee):** Providing services and information to government employees. (e.g., online access to salary slips, e-learning).\r\n\r\n---\r\n## 📱 5. Mobile Computing & Internet of Things (IoT)\r\n\r\n### Mobile Computing\r\nThis is technology that allows the transmission of data, voice, and video via portable, wireless-enabled devices like smartphones, tablets, and laptops. It enables you to work and access information from anywhere.\r\n- **Advantages:** Portability, increased productivity, and instant communication.\r\n\r\n### Internet of Things (IoT)\r\nThe **IoT** is a giant network of interconnected physical devices—from smartwatches and home appliances to cars and industrial machinery—that are embedded with sensors and software to collect and exchange data over the internet without requiring human interaction.\r\n- **Analogy:** Giving everyday objects a \"digital brain\" so they can communicate with each other.\r\n- **Example:** A smart thermostat that learns your schedule and adjusts the temperature automatically, or a smartwatch that tracks your health and sends data to your doctor.\r\n\r\n---\r\n## 📋 6. COMPLETE EXERCISE SOLUTIONS\r\n\r\n### **1. Answer the following questions:**\r\n**a. What is Artificial intelligence? List any two applications of AI.**\r\n**Ans:** Artificial intelligence is the ability of a computer or machine to think, learn, and perform tasks that normally require human intelligence. Two applications are **AI in Healthcare** (for diagnostics) and **AI in Gaming** (for smart characters).\r\n\r\n**b. List any two advantages and disadvantages of cloud computing.**\r\n**Ans:**\r\n- **Advantages:** 1) We can access files from any location with an internet connection. 2) It helps companies reduce expenses on hardware.\r\n- **Disadvantages:** 1) There may be data security and privacy problems. 2) A stable internet connection is mandatory to use it.\r\n\r\n**c. What is e-governance? What are its advantages?**\r\n**Ans:** E-Governance is the application of electronic means (ICT) to improve the interaction between the government and its citizens. Its advantages include increased transparency, faster delivery of services, and greater convenience for the public.\r\n\r\n### **2. Write the full forms of the following:**\r\n- **IaaS:** Infrastructure as a Service\r\n- **PaaS:** Platform as a Service\r\n- **SaaS:** Software as a Service\r\n- **AI:** Artificial Intelligence\r\n- **VRML:** Virtual Reality Modeling Language\r\n- **G2C:** Government to Citizen\r\n- **G2B:** Government to Business\r\n- **G2G:** Government to Government\r\n- **G2E:** Government to Employee\r\n- **IoT:** Internet of Things\r\n\r\n### **3. True or False:**\r\na. Technology has enabled people to communicate and interact in more effective and convenient ways. **(True)**\r\nb. Gmail users can access files and applications hosted by Google using any device that can access the Internet. **(True)**\r\nc. A Public Cloud is the cloud computing that is owned by a single organization. **(False)** *Correction: That is a Private Cloud.*\r\nd. Infrastructure as a service of cloud computing provides software applications over the Internet. **(False)** *Correction: That is Software as a Service (SaaS).*\r\ne. Virtual Reality is the real environment that presents everything fake. **(False)** *Correction: It is an artificial/simulated environment that feels real.*\r\n\r\n### **4. Choose the correct option:**\r\na. The E-Governance that refers to the basic government services that are accessed by public is…\r\n   - **(i) G2C**\r\nb. An artificial environment created with the computer and software is known as…\r\n   - **(ii) Virtual Reality**\r\nc. The friendly female voice-activated personal assistant that is used in iPhone and iPad is…\r\n   - **(ii) Siri**\r\nd. A machine having AI will be able to…\r\n   - **(iv) All of the above** (Think, Decide, Learn)\r\n\r\n### **5. Write the technical terms:**\r\na. The network of large groups of servers that provides storage and applications services...\r\n   - **Cloud Computing**\r\nb. The ability that understand natural language and capable of thinking and learning itself.\r\n   - **Artificial Intelligence (AI)**\r\nc. A system that transfers data over a network without human-to-human interaction.\r\n   - **Internet of Things (IoT)**\r\nd. The technology that allows transmission of data, voice and video via any wireless enabled device.\r\n   - **Mobile Computing**\r\n---\r\n## ✅ 7. CHAPTER CHECKLIST & EXAM TIPS\r\n**Exam Hotspots 🔥:**\r\n-   **Cloud Service Models:** The difference between IaaS, PaaS, and SaaS is a very common question. Remember the pizza analogy!\r\n-   **Acronyms:** Be sure to memorize the full forms of all the technical terms (AI, IoT, G2C, etc.).\r\n-   **Definitions:** You must be able to define each of the main technologies (Cloud, AI, VR, IoT).\r\n-   **Applications:** Be ready to list at least two practical applications for each technology.\r\n\r\n**Your Pre-Exam Checklist:**\r\n- [ ] I can define Cloud Computing and list its three service models.\r\n- [ ] I can define Artificial Intelligence and give two examples like Siri or Alexa.\r\n- [ ] I can explain what Virtual Reality is and where it\'s used.\r\n- [ ] I can define E-Governance and explain the G2C model.\r\n- [ ] I know the full forms of IoT, SaaS, and G2B.\r\n---\r\n## 🎊 CONCLUSION\r\nContemporary technologies are not just tools; they are powerful forces that are reshaping our industries, governments, and daily lives. Understanding them is essential for being an informed citizen in the 21st century. This chapter gives you the foundational knowledge to appreciate and navigate this rapidly evolving digital world.\r\n**Key to Success:** Understand the Core Definitions + Remember the Acronyms + Connect Concepts to Real-Life Examples = A+!', 1, '2025-07-25 01:11:38', '2025-09-16 15:20:38'),
(97, 13201, '# Networking & Telecommunication - Grade 10 Notes\r\n## Complete Chapter Notes with All Exercises - NEB Curriculum\r\n---\r\n## 🎯 Chapter Overview\r\n**Welcome to the connected world!** From sending a message to a friend to streaming videos online, everything you do on the internet is made possible by networking and telecommunication. This chapter is your guide to understanding the magic behind how computers and devices talk to each other.\r\n**This is a fundamental chapter that explains the backbone of our digital society.** We\'ll explore everything from the basic modes of data transmission to the different types of networks, the hardware that powers them, and the rules (protocols) they follow. Every exercise from your textbook is solved here with simple analogies and clear explanations to make you a networking pro.\r\n**Weightage:** 7-9 marks in SEE examination\r\n**Time Required:** 15-20 periods\r\n---\r\n## 📚 Learning Objectives\r\nAfter studying this chapter, you will be able to:\r\n- Define data communication, telecommunication, and computer networks.\r\n- Differentiate between simplex, half-duplex, and full-duplex transmission modes.\r\n- Explain the advantages and disadvantages of computer networks.\r\n- Differentiate between guided (wired) and unguided (wireless) communication media.\r\n- Describe the function of key networking devices like hubs, switches, routers, and modems.\r\n- Differentiate between network types (LAN, MAN, WAN) and models (Client-Server, Peer-to-Peer).\r\n- Explain different network topologies (Bus, Ring, Star).\r\n- Understand the role of communication protocols.\r\n---\r\n## 📡 1. Fundamentals of Communication\r\n**Data Communication** is the process of transmitting data electronically from one device to another through a communication medium. **Telecommunication** is the broader term for any communication over a significant distance by electronic means (e.g., telephone, radio, internet).\r\n\r\n### Transmission Modes\r\nThis describes the direction of data flow between two devices.\r\n\r\n| Mode | Description | Analogy | Examples |\r\n|---|---|---|---|\r\n| **Simplex** | Communication is **one-way only**. | A one-way street or a TV broadcast. The station sends a signal, but you can\'t send one back through your TV. | Radio, Television, Keyboard to CPU. |\r\n| **Half-Duplex** | Communication is **two-way**, but **not at the same time**. | A walkie-talkie conversation. One person must finish speaking before the other can reply. | Walkie-Talkie. |\r\n| **Full-Duplex** | Communication is **two-way and simultaneous**. | A telephone conversation. Both people can talk and listen at the same time. | Mobile Phone, Video Call. |\r\n\r\n\r\n---\r\n## 💻 2. Computer Networks: The Big Picture\r\nA **Computer Network** is a group of two or more interconnected computers and other devices that can communicate and share resources (like files, printers, and internet connections).\r\n\r\n### Advantages of Computer Networks\r\n- **Resource Sharing:** Devices like printers and scanners can be shared among many users, saving money.\r\n- **Cost Reduction:** Sharing hardware and software reduces overall expenses for an office or organization.\r\n- **Easy Communication:** Users can easily send files and messages to each other.\r\n- **Centralized Data:** Data can be stored on a central server, making it easy to manage, back up, and access.\r\n\r\n### Disadvantages of Computer Networks\r\n- **Security Risks:** Networks are vulnerable to hacking, viruses, and data theft if not properly secured.\r\n- **High Setup Cost:** The initial cost of cables, devices, and setup can be expensive.\r\n- **Management Complexity:** Larger networks require skilled technicians to manage and maintain them.\r\n- **Privacy Concerns:** Shared data can sometimes lead to a lack of privacy.\r\n\r\n---\r\n## 🔌 3. Network Components: The Building Blocks\r\n\r\n### A. Communication Media (The Path)\r\nThis is the physical path through which data travels.\r\n\r\n- **Guided Media (Wired):** Uses physical cables.\r\n  1.  **Twisted Pair Cable:** Two insulated copper wires twisted together. (Used in LANs, telephone lines).\r\n  2.  **Coaxial Cable:** A central copper conductor surrounded by insulation and a braided shield. (Used for cable TV).\r\n  3.  **Fiber Optic Cable:** Consists of thin strands of glass that transmit data as pulses of **light**. It is the fastest and most secure guided medium.\r\n\r\n- **Unguided Media (Wireless):** Transmits data through the air using electromagnetic waves.\r\n  1.  **Radio Wave:** Used for Wi-Fi, Bluetooth, and mobile communication.\r\n  2.  **Microwave:** Used for long-distance communication (e.g., satellite).\r\n  3.  **Infrared Wave:** Used for short-range communication (e.g., TV remotes).\r\n\r\n### B. Network Devices (The Traffic Controllers)\r\n\r\n| Device | Function | Analogy |\r\n|---|---|---|\r\n| **NIC** (Network Interface Card) | A hardware card that allows a computer to connect to a network. | A computer\'s \"passport\" or \"ID card\" to join the network. |\r\n| **Hub** | A simple, non-intelligent device that connects multiple computers. It broadcasts data to **all** connected devices. | A \"dumb postman\" who shouts a message in a room for everyone to hear. |\r\n| **Switch** | An intelligent device that connects multiple computers. It sends data **only to the intended recipient** device. | A \"smart postman\" who delivers a letter directly to the correct person\'s mailbox. |\r\n| **Router** | A device that connects **different networks** and intelligently finds the **best path** for data to travel across the internet. | The \"traffic police\" at a major intersection, directing traffic between different city roads. |\r\n| **Modem** (Modulator/Demodulator) | Converts a computer\'s digital signals to analog signals for telephone lines, and vice versa. | A \"translator\" between the computer\'s digital language and the phone line\'s analog language. |\r\n| **Repeater** | Boosts a weak signal to extend the range of a network. | A \"megaphone\" that re-shouts a message to make it travel farther. |\r\n\r\n---\r\n## 🌐 4. Network Architecture & Topologies\r\n\r\n### A. Types of Networks (by size)\r\n- **LAN (Local Area Network):** A network confined to a small area, like a single room, building, or campus.\r\n- **MAN (Metropolitan Area Network):** A network that covers a larger area, like an entire city.\r\n- **WAN (Wide Area Network):** A network that extends over a large geographical area, like a country or the entire globe. The **Internet** is the largest WAN.\r\n\r\n### B. Network Models\r\n| Client-Server Model | Peer-to-Peer (P2P) Model |\r\n|---|---|\r\n| A powerful central computer called a **Server** provides resources to other computers called **Clients** (Workstations). | All computers have equal status; there is **no central server**. Each computer acts as both a client and a server. |\r\n| High security and centralized management. | Low security and decentralized management. |\r\n| Also called a \"domain model\". | Also called a \"workgroup model\". |\r\n\r\n### C. Network Topology (The Layout)\r\nTopology refers to the physical or logical arrangement of computers in a network.\r\n\r\n- **Bus Topology:** All devices are connected to a single common cable called a backbone or trunk.\r\n  - **Advantages:** Simple and cheap to install.\r\n  - **Disadvantages:** If the main cable fails, the entire network goes down. Difficult to troubleshoot.\r\n- **Ring Topology:** All devices are connected in a closed loop, with data traveling in one direction.\r\n  - **Advantages:** Orderly data flow, performs well under heavy load.\r\n  - **Disadvantages:** Failure of one computer can break the entire ring.\r\n- **Star Topology:** All devices are connected to a central device (like a hub or switch).\r\n  - **Advantages:** **Most reliable.** If one cable fails, only that one computer is affected. Easy to add new devices and troubleshoot.\r\n  - **Disadvantages:** If the central device fails, the entire network goes down.\r\n\r\n\r\n---\r\n## 📋 5. COMPLETE EXERCISE SOLUTIONS\r\n\r\n### **1. Answer the following questions:**\r\n**a. What is a computer network? List any 3 advantages.**\r\n**Ans:** A computer network is a group of interconnected computers and devices set up to communicate and share resources. Three advantages are:\r\n1.  **Resource Sharing:** Sharing hardware like printers and software saves costs.\r\n2.  **Easy Communication:** Files and messages can be transferred instantly.\r\n3.  **Cost Reduction:** Reduces office expenses by sharing expensive devices.\r\n\r\n**b. Differentiate between a Hub and a Switch.**\r\n**Ans:**\r\n| Hub | Switch |\r\n|---|---|\r\n| A non-intelligent device that broadcasts data to all connected computers. | An intelligent device that sends data only to the specific destination computer. |\r\n| Less secure as all devices receive the data. | More secure as only the intended recipient gets the data. |\r\n| Cheaper. | More expensive. |\r\n\r\n**c. What is network topology? List its types.**\r\n**Ans:** Network topology is the physical layout or arrangement of computers and other devices in a network. The main types are **Bus topology**, **Ring topology**, and **Star topology**.\r\n\r\n### **2. Write the full forms of the following:**\r\n- **UTP:** Unshielded Twisted Pair\r\n- **NIC:** Network Interface Card\r\n- **MODEM:** Modulator Demodulator\r\n- **LAN:** Local Area Network\r\n- **MAN:** Metropolitan Area Network\r\n- **WAN:** Wide Area Network\r\n- **TCP/IP:** Transmission Control Protocol / Internet Protocol\r\n- **FTP:** File Transfer Protocol\r\n- **HTTP:** HyperText Transfer Protocol\r\n- **SMTP:** Simple Mail Transfer Protocol\r\n- **POP:** Post Office Protocol\r\n\r\n### **3. Write the technical terms for the following:**\r\na. A group of interconnected computers. -> **Computer Network**\r\nb. A path through which data is transmitted from one computer to another. -> **Communication Media**\r\nc. A network of computers formed by using cables. -> **Wired Network**\r\nd. A transmission medium through which data are transmitted in the form of light. -> **Fiber Optic Cable**\r\ne. A computer on the network that provides resources to other computers. -> **Server**\r\nf. A computer on the network that uses resources of the network. -> **Workstation / Client**\r\ng. A card through which a computer is connected on the network. -> **NIC (Network Interface Card)**\r\nh. A network device that transmits signals to a destination node on the network. -> **Switch**\r\ni. A network device that can determine the best path for forwarding data packets. -> **Router**\r\nj. A device that converts digital signals into analog signals and vice versa. -> **Modem**\r\nk. A network of computers in a room, building, or campus. -> **LAN (Local Area Network)**\r\nl. The network model where each node has equal rights. -> **Peer-to-Peer Model**\r\nm. The cabling pattern where each node is individually connected to a centrally located device. -> **Star Topology**\r\nn. A set of rules by which computers communicate with each other on the network. -> **Protocol**\r\n---\r\n## ✅ 6. CHAPTER CHECKLIST & EXAM TIPS\r\n**Exam Hotspots 🔥:**\r\n-   **Transmission Modes:** The difference between Simplex, Half-Duplex, and Full-Duplex is a classic question.\r\n-   **Network Devices:** Be able to state the function of a Hub, Switch, Router, and Modem. The Hub vs. Switch difference is very important.\r\n-   **Network Types:** Know the full forms and basic difference between LAN, MAN, and WAN.\r\n-   **Topologies:** The advantages and disadvantages of Bus and Star topologies are frequently asked.\r\n\r\n**Your Pre-Exam Checklist:**\r\n- [ ] I can explain the three modes of data transmission with examples.\r\n- [ ] I can differentiate between a Hub and a Switch.\r\n- [ ] I can name the three main types of guided media.\r\n- [ ] I can define LAN, MAN, and WAN.\r\n- [ ] I can explain the Client-Server and Peer-to-Peer network models.\r\n- [ ] I can list two advantages of Star topology.\r\n---\r\n## 🎊 CONCLUSION\r\nNetworking is the invisible force that powers our modern digital lives. Understanding its fundamental concepts—from the cables in the ground to the protocols in the software—is essential for anyone living in the 21st century. This chapter provides a solid foundation for comprehending how we all stay connected.\r\n**Key to Success:** Learn the Analogies + Master the Device Functions + Understand the Topologies = A Strong Connection to Good Marks!', 1, '2025-07-25 01:11:38', '2025-09-16 15:20:38'),
(98, 13212, '# Number System - Grade 10 Notes\r\n\r\n## Complete Chapter Notes with All Exercises - NEB Curriculum\r\n\r\n## 🎯 Chapter Overview\r\n\r\nHave you ever wondered how computers, which are just electronic circuits, can handle everything from photos and videos to complex calculations? The secret lies in the Number System. While we humans use a system with ten digits (0-9), computers speak a much simpler language with just two: 0 and 1. \r\n\r\nThis chapter is your key to understanding the language of computers. We will explore the different number systems used in computing, with a focus on how to convert numbers between them and perform basic calculations in the binary system. This is a fundamental and high-scoring topic in computer science. Every concept is broken down into simple steps with plenty of examples to guide you.\r\n\r\n**Weightage:** 6-8 marks in SEE examination  \r\n**Time Required:** 12-15 periods\r\n\r\n## 📚 Learning Objectives\r\n\r\nAfter studying this chapter, you will be able to:\r\n\r\n- Define what a number system is and identify its different types\r\n- Understand the concept of base or radix\r\n- Convert numbers from one number system (Decimal, Binary, Octal, Hexadecimal) to another\r\n- Perform binary arithmetic: addition, subtraction, and multiplication\r\n- Define fundamental data units like BIT and Byte\r\n\r\n## 🔢 1. Introduction to Number Systems\r\n\r\nA **Number System** is a systematic way of representing or expressing numbers. Every number system has a set of unique characters or digits and a specific **base (or radix)**, which is the total number of unique digits used in that system.\r\n\r\n### Types of Number Systems\r\n\r\n| System | Base | Digits Used | Example | Why it\'s important |\r\n|--------|------|-------------|---------|-------------------|\r\n| **Decimal** | **10** | 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 | (257)₁₀ | The everyday system used by humans. |\r\n| **Binary** | **2** | 0, 1 | (1101)₂ | The fundamental language of computers (0=Off, 1=On). |\r\n| **Octal** | **8** | 0, 1, 2, 3, 4, 5, 6, 7 | (401)₈ | A shorthand for representing long binary numbers. |\r\n| **Hexadecimal** | **16** | 0-9, A(10), B(11), C(12), D(13), E(14), F(15) | (1A5)₁₆ | A more compact shorthand for binary; used in memory addressing and color codes (e.g., #FFFFFF for white). |\r\n\r\n### BITs and Bytes: The Units of Data\r\n\r\n- **BIT (Binary Digit):** The smallest unit of data in a computer. It can have a value of either **0** or **1**.\r\n- **Byte:** A group of **8 bits**. A byte is the basic unit used to represent a character, like the letter \'A\' or the symbol \'$\'.\r\n  - 1 Byte = 8 Bits\r\n  - 1 Kilobyte (KB) = 1024 Bytes\r\n\r\n## 🔄 2. Number System Conversions\r\n\r\nThis is the most important skill to learn in this chapter. Here are the step-by-step methods for all conversions.\r\n\r\n### A. Conversion from Decimal to Other Bases (Division Method)\r\n\r\n**Rule:** Continuously divide the decimal number by the new base until the quotient is 0. Then, write the remainders in **reverse order** (from bottom to top).\r\n\r\n#### 1. Decimal to Binary\r\n\r\n**Convert (25)₁₀ to Binary:**\r\n\r\n```\r\n2 | 25 | Remainder\r\n2 | 12 |     1\r\n2 |  6 |     0\r\n2 |  3 |     0\r\n2 |  1 |     1\r\n  |  0 |     1   (Read upwards)\r\n```\r\n\r\n**Answer:** (25)₁₀ = (11001)₂\r\n\r\n#### 2. Decimal to Octal\r\n\r\n**Convert (150)₁₀ to Octal:**\r\n\r\n```\r\n8 | 150 | Remainder\r\n8 |  18 |     6\r\n8 |   2 |     2\r\n  |   0 |     2   (Read upwards)\r\n```\r\n\r\n**Answer:** (150)₁₀ = (226)₈\r\n\r\n#### 3. Decimal to Hexadecimal\r\n\r\n**Convert (423)₁₀ to Hexadecimal:** (Remember: 10=A, 11=B, 12=C, 13=D, ...)\r\n\r\n```\r\n16 | 423 | Remainder\r\n16 |  26 |     7\r\n16 |   1 |    10 (which is A)\r\n   |   0 |     1         (Read upwards)\r\n```\r\n\r\n**Answer:** (423)₁₀ = (1A7)₁₆\r\n\r\n### B. Conversion to Decimal from Other Bases (Power Method)\r\n\r\n**Rule:** Multiply each digit by its positional weight (base raised to the power of its position, starting from 0 on the right) and add the results.\r\n\r\n#### 1. Binary to Decimal\r\n\r\nConvert (1101)₂ to Decimal:\r\n= (1×2³) + (1×2²) + (0×2¹) + (1×2⁰)\r\n= (1×8) + (1×4) + (0×2) + (1×1)\r\n= 8 + 4 + 0 + 1 = 13\r\n\r\n**Answer:** (1101)₂ = (13)₁₀\r\n\r\n#### 2. Octal to Decimal\r\n\r\nConvert (345)₈ to Decimal:\r\n= (3×8²) + (4×8¹) + (5×8⁰)\r\n= (3×64) + (4×8) + (5×1)\r\n= 192 + 32 + 5 = 229\r\n\r\n**Answer:** (345)₈ = (229)₁₀\r\n\r\n#### 3. Hexadecimal to Decimal\r\n\r\nConvert (2A7)₁₆ to Decimal: (Remember: A=10)\r\n= (2×16²) + (10×16¹) + (7×16⁰)\r\n= (2×256) + (10×16) + (7×1)\r\n= 512 + 160 + 7 = 679\r\n\r\n**Answer:** (2A7)₁₆ = (679)₁₀\r\n\r\n### C. Conversions Between Binary, Octal, and Hexadecimal (Shortcut Method)\r\n\r\n**Rule:** Use grouping. This is much faster than converting to decimal first.\r\n\r\n#### 1. Binary to Octal (Group in 3s)\r\n\r\n**Convert (11010111)₂ to Octal:**\r\n- Group digits in sets of three from the right: 11 010 111\r\n- Add leading zeros to the first group to make it three digits: 011 010 111\r\n- Convert each group: 011 = 3, 010 = 2, 111 = 7\r\n\r\n**Answer:** (327)₈\r\n\r\n#### 2. Binary to Hexadecimal (Group in 4s)\r\n\r\n**Convert (11010111)₂ to Hexadecimal:**\r\n- Group digits in sets of four from the right: 1101 0111\r\n- Convert each group: 1101 = 13 = D, 0111 = 7\r\n\r\n**Answer:** (D7)₁₆\r\n\r\n#### 3. Octal to Binary (Expand to 3 bits)\r\n\r\n**Convert (562)₈ to Binary:**\r\n- Convert each octal digit to its 3-bit binary equivalent:\r\n- 5 = 101, 6 = 110, 2 = 010\r\n- Combine them: 101 110 010\r\n\r\n**Answer:** (101110010)₂\r\n\r\n#### 4. Hexadecimal to Binary (Expand to 4 bits)\r\n\r\n**Convert (9F2)₁₆ to Binary:**\r\n- Convert each hexadecimal digit to its 4-bit binary equivalent:\r\n- 9 = 1001, F (15) = 1111, 2 = 0010\r\n- Combine them: 1001 1111 0010\r\n\r\n**Answer:** (100111110010)₂\r\n\r\n## ➕ 3. Binary Arithmetic\r\n\r\nComputers perform all calculations using binary arithmetic.\r\n\r\n### A. Binary Addition\r\n\r\n**Rules:**\r\n- 0 + 0 = 0\r\n- 0 + 1 = 1\r\n- 1 + 0 = 1\r\n- 1 + 1 = 0 (with a **carry** of 1 to the next column)\r\n- 1 + 1 + 1 = 1 (with a **carry** of 1 to the next column)\r\n\r\n**Example: Add (1101)₂ and (1011)₂**\r\n\r\n```\r\n  111   (Carries)\r\n  1101\r\n+ 1011\r\n-------\r\n 11000\r\n```\r\n\r\n**Answer:** (11000)₂\r\n\r\n### B. Binary Subtraction\r\n\r\n**Rules:**\r\n- 0 − 0 = 0\r\n- 1 − 0 = 1\r\n- 1 − 1 = 0\r\n- 0 − 1 = 1 (with a **borrow** of 1 from the next column)\r\n\r\n**Example: Subtract (101)₂ from (1100)₂**\r\n\r\n```\r\n  1 1 0 0  (Original)\r\n-   1 0 1\r\n---------\r\n    1 1 1\r\n```\r\n\r\n**Explanation:**\r\n- Rightmost column: 0 - 1 requires a borrow. The next 0 also needs to borrow, so we borrow from the \'1\' two places over. The first \'0\' becomes \'10\' (2), then lends one, becoming \'1\'. The rightmost \'0\' becomes \'10\' (2).\r\n- So, 10 - 1 = 1. Next column is 1 - 0 = 1. Next is 0 - 1, requiring a borrow. The leftmost \'1\' becomes \'0\', this column becomes 10 - 1 = 1.\r\n\r\n**Answer:** (0111)₂ or (111)₂\r\n\r\n### C. Binary Multiplication\r\n\r\n**Rules:** (Same as decimal multiplication)\r\n- 0 × 0 = 0\r\n- 0 × 1 = 0\r\n- 1 × 0 = 0\r\n- 1 × 1 = 1\r\n\r\n**Example: Multiply (101)₂ by (11)₂**\r\n\r\n```\r\n    101\r\n  x  11\r\n  ------\r\n    101   (101 × 1)\r\n+ 1010   (101 × 1, shifted one place left)\r\n  --------\r\n  1111\r\n```\r\n\r\n**Answer:** (1111)₂\r\n\r\n## 📋 4. Complete Exercise Solutions\r\n\r\n### 1. Answer the following questions:\r\n\r\n**a. What is a number system? List the different types of number systems.**\r\n\r\n**Answer:** A Number System is a method or system used to represent numbers. The four common types used in computing are:\r\n- Decimal Number System (Base-10)\r\n- Binary Number System (Base-2)\r\n- Octal Number System (Base-8)\r\n- Hexadecimal Number System (Base-16)\r\n\r\n**b. What is a binary number system?**\r\n\r\n**Answer:** The number system that uses only two digits, 0 and 1, is known as the binary number system. It is the fundamental language of computers.\r\n\r\n**c. What is a hexadecimal number system? List its digits.**\r\n\r\n**Answer:** The number system that uses 16 unique digits to represent numbers is known as the hexadecimal number system. Its digits are 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, and F.\r\n\r\n**d. What is an octal number system? List its digits.**\r\n\r\n**Answer:** The number system that uses 8 unique digits to represent numbers is known as the octal number system. Its digits are 0, 1, 2, 3, 4, 5, 6, and 7.\r\n\r\n**e. What are BIT and Byte?**\r\n\r\n**Answer:**\r\n- **BIT (Binary Digit):** The smallest unit of data in a computer, representing either a 0 or a 1.\r\n- **Byte:** A group of 8 bits, typically used to represent a single character.\r\n\r\n### 2. Perform the following Binary Calculations:\r\n\r\n**(More Solved Examples)**\r\n\r\n**a. Addition:** (11101)₂ + (10110)₂\r\n\r\n```\r\n  111    (Carries)\r\n  11101\r\n+ 10110\r\n---------\r\n 110011\r\n```\r\n\r\n**Answer:** (110011)₂\r\n\r\n**b. Subtraction:** (11011)₂ − (1110)₂\r\n\r\n```\r\n  11011\r\n-  1110\r\n---------\r\n   1101\r\n```\r\n\r\n**Answer:** (1101)₂\r\n\r\n**c. Multiplication:** (110)₂ × (101)₂\r\n\r\n```\r\n    110\r\n  x 101\r\n  ------\r\n    110\r\n   0000\r\n+ 11000\r\n---------\r\n  11110\r\n```\r\n\r\n**Answer:** (11110)₂\r\n\r\n## ✅ 5. Chapter Checklist & Exam Tips\r\n\r\n**Exam Hotspots 🔥:**\r\n\r\n- **Conversions:** This is the most frequently tested topic. Be perfect in converting from Decimal to Binary and Binary to Decimal. The shortcut methods (Binary to Octal/Hex) are also very important.\r\n- **Binary Arithmetic:** Expect at least one question on binary addition or subtraction.\r\n- **Definitions:** Be ready to define the four number systems, BIT, and Byte.\r\n\r\n**Your Pre-Exam Checklist:**\r\n\r\n- [ ] I can define the four main number systems and their bases.\r\n- [ ] I can convert a decimal number to binary, octal, and hexadecimal.\r\n- [ ] I can convert a binary, octal, or hexadecimal number to decimal.\r\n- [ ] I can use the shortcut method to convert between binary and octal/hexadecimal.\r\n- [ ] I can perform binary addition, subtraction, and multiplication.\r\n\r\n## 🎊 Conclusion\r\n\r\nUnderstanding number systems is like learning the alphabet of the digital world. While it seems abstract, it\'s the foundation upon which all modern technology is built. Mastering conversions and binary math will give you a deeper appreciation for how computers work and a solid base for further studies in science and technology.\r\n\r\n**Key to Success:** Practice Conversions Daily + Memorize the Binary Math Rules = Top Marks!', 1, '2025-07-25 01:11:38', '2025-09-16 15:20:38');
INSERT INTO `course_notes_content` (`id`, `topic_id`, `content`, `markdown_format`, `created_at`, `updated_at`) VALUES
(99, 13209, '# Computer Security - Grade 10 Notes\r\n\r\n## Complete Chapter Notes with All Exercises - NEB Curriculum\r\n\r\n## 🎯 Chapter Overview\r\n\r\nIn today\'s digital world, our computers store everything from personal photos and school projects to bank details and private messages. But just like we lock our homes to keep burglars out, we need to protect our computers from digital threats. Computer Security is like having a digital bodyguard for your computer and data.\r\n\r\nThis chapter will teach you about the various threats that can harm your computer and data, and more importantly, how to protect against them. From understanding viruses and malware to learning about firewalls and backup systems, you\'ll gain the knowledge to keep your digital life safe and secure.\r\n\r\n**Weightage:** 6-8 marks in SEE examination  \r\n**Time Required:** 10-12 periods\r\n\r\n## 📚 Learning Objectives\r\n\r\nAfter studying this chapter, you will be able to:\r\n\r\n- Define computer security and understand its importance\r\n- Identify different types of security threats (physical and non-physical)\r\n- Explain malicious codes like viruses, worms, and trojans\r\n- Understand information security measures\r\n- Learn about hardware security and power protection\r\n- Apply preventive measures to protect computer systems\r\n\r\n## 🔒 1. Introduction to Computer Security\r\n\r\n**Computer Security** is the protection of computer data, information, programs, and hardware from malicious attackers and accidental harm. It\'s like having multiple layers of protection around your digital assets.\r\n\r\n### Why is Computer Security Important?\r\n\r\n- **Data Protection**: Keeps your personal files, photos, and documents safe\r\n- **Privacy**: Prevents unauthorized access to your private information\r\n- **System Integrity**: Ensures your computer works properly without disruption\r\n- **Financial Safety**: Protects against cyber theft and fraud\r\n\r\n## ⚠️ 2. Computer Security Threats\r\n\r\nA **Computer Security Threat** is anything that has the potential to cause harm to data, information, software, or hardware.\r\n\r\n### Types of Security Threats\r\n\r\n| Threat Type | Definition | Examples |\r\n|-------------|------------|----------|\r\n| **Physical Threats** | Threats that can physically damage computer hardware | Fire, theft, power failure, natural disasters, faulty wiring |\r\n| **Non-Physical Threats** | Threats that attack through software or network | Viruses, malware, hacking, unauthorized access |\r\n\r\n### Real-World Examples\r\n\r\n- **Physical**: A power surge damaging your computer\'s motherboard\r\n- **Non-Physical**: A virus deleting your important files\r\n\r\n## 🦠 3. Malicious Code (Malware)\r\n\r\n**Malicious Code** is harmful computer code designed to cause undesired effects, security breaches, or damage to a computer system.\r\n\r\n### Types of Malicious Code\r\n\r\n#### A. Computer Virus\r\n- **Definition**: A destructive program that hides in host files and replicates itself\r\n- **Characteristics**:\r\n  - Hides inside other programs or files\r\n  - Can replicate and spread to other files\r\n  - Requires a host file to survive\r\n\r\n**Destructive Tasks of Viruses:**\r\n- Display unnecessary messages and images\r\n- Run unwanted programs\r\n- Delete or corrupt files\r\n- Slow down computer performance\r\n\r\n**Routes of Virus Transmission:**\r\n- Using pirated software\r\n- Sharing infected portable storage devices\r\n- Downloading files from unreliable websites\r\n- Exchanging data on networks\r\n- Opening virus-infected emails\r\n\r\n**Symptoms of Virus Infection:**\r\n- Changes in file sizes\r\n- Missing files or folders\r\n- Unusual error messages\r\n- Programs hang frequently\r\n- Slow system performance\r\n\r\n#### B. Computer Worms\r\n- **Definition**: Malicious code that doesn\'t hide in files but spreads from computer to computer\r\n- **Characteristics**:\r\n  - Don\'t need host files\r\n  - Can replicate themselves\r\n  - Spread through networks, emails, and storage devices\r\n\r\n#### C. Trojan Horse\r\n- **Definition**: A destructive program that pretends to be useful but performs malicious actions\r\n- **Characteristics**:\r\n  - Appears as legitimate software\r\n  - Doesn\'t replicate itself\r\n  - Creates backdoors for attackers\r\n\r\n### Other Types of Malware\r\n\r\n| Malware Type | Description |\r\n|--------------|-------------|\r\n| **Spyware** | Monitors user activities and steals information |\r\n| **Ransomware** | Locks files and demands payment for access |\r\n| **Adware** | Shows unwanted advertisements |\r\n| **Scareware** | Shows fake virus alerts to trick users |\r\n\r\n## 🛡️ 4. Information Security Measures\r\n\r\n**Information Security** is the protection of data, information, and software from being lost or damaged due to accidental or intentional harm.\r\n\r\n### A. Authentication Systems\r\n\r\n#### 1. Password Protection\r\n- **Definition**: A secret word or sequence of characters that provides access\r\n- **Why use passwords?**: To protect files from unauthorized users\r\n- **Strong Password Guidelines**:\r\n  - Use combination of letters, numbers, and symbols\r\n  - Minimum 8 characters long\r\n  - Avoid personal information\r\n  - Use different passwords for different accounts\r\n\r\n#### 2. Biometric Authentication\r\n- **Definition**: Uses unique physical characteristics for identification\r\n- **Examples**: Fingerprint, facial recognition, iris scan, voice recognition\r\n- **Advantages**: Very difficult to fake or steal\r\n\r\n### B. Cryptography\r\n- **Definition**: The method of protecting data by converting it into unreadable format\r\n- **Process**:\r\n  1. **Encryption**: Converting readable text into unreadable format\r\n  2. **Decryption**: Converting encrypted text back to readable format\r\n\r\n```\r\nOriginal Text → [Encryption] → Encrypted Text → [Decryption] → Original Text\r\n\"Hello\"      →               → \"Khoor\"        →              → \"Hello\"\r\n```\r\n\r\n### C. Firewall\r\n- **Definition**: A security barrier that protects computer systems from external threats\r\n- **Types**:\r\n  - **Software Firewall**: Installed on individual computers\r\n  - **Hardware Firewall**: Physical device protecting entire networks\r\n\r\n**Purposes of Firewall:**\r\n- Block unwanted network traffic\r\n- Protect private networks from unauthorized access\r\n- Block unsuitable website content\r\n- Prevent entry of viruses and worms\r\n\r\n### D. Antivirus Software\r\n- **Definition**: Programs that detect, prevent, and remove malicious software\r\n\r\n**Popular Antivirus Software:**\r\n- Kaspersky Antivirus\r\n- Avira Antivirus\r\n- Avast Antivirus\r\n- AVG Antivirus\r\n- Windows Defender\r\n\r\n**Functions of Antivirus:**\r\n- Real-time scanning\r\n- Regular system scans\r\n- Automatic updates\r\n- Quarantine infected files\r\n\r\n### E. Backup Systems\r\n- **Definition**: Creating duplicate copies of data, information, and software\r\n\r\n**Importance of Backup:**\r\n- Protects against data loss\r\n- Helps recover files if system crashes\r\n- Protects against hardware failures\r\n- Guards against accidental deletion\r\n\r\n**Types of Backup:**\r\n- **Full Backup**: Complete copy of all data\r\n- **Incremental Backup**: Only changed files since last backup\r\n- **Cloud Backup**: Data stored on remote servers\r\n\r\n## 🔧 5. Hardware Security\r\n\r\n**Hardware Security** refers to the protection of computer hardware from being damaged or lost.\r\n\r\n### Hardware Security Measures\r\n\r\n#### A. Regular Maintenance\r\n- **Purpose**: Find problems before they cause major damage\r\n- **Benefits**:\r\n  - Keeps hardware in good working condition\r\n  - Extends lifespan of components\r\n  - Prevents unexpected failures\r\n\r\n**Maintenance Activities:**\r\n- Cleaning dust from components\r\n- Checking cable connections\r\n- Monitoring temperature\r\n- Updating drivers\r\n\r\n#### B. Environmental Protection\r\n- **Air Conditioning**: Maintains optimal temperature\r\n- **Dust Protection**: Prevents dust accumulation\r\n- **Humidity Control**: Prevents moisture damage\r\n\r\n#### C. Physical Security\r\n- **Protection from theft**: Locks, security cameras (CCTV)\r\n- **Fire protection**: Fire alarms, fire extinguishers\r\n- **Insurance**: Financial protection against losses\r\n\r\n### Power Protection Devices\r\n\r\n**Power Protection Device** protects computer hardware from voltage fluctuations, power failures, and electrical surges.\r\n\r\n| Device | Function |\r\n|--------|----------|\r\n| **UPS (Uninterruptible Power Supply)** | Provides backup power during outages |\r\n| **Volt Guard** | Protects against voltage fluctuations |\r\n| **Spike Guard** | Protects against power surges |\r\n| **Stabilizer** | Maintains steady voltage output |\r\n| **CVT (Constant Voltage Transformer)** | Regulates voltage automatically |\r\n\r\n#### Role of UPS in Computer Security\r\n- Provides backup power during outages\r\n- Protects against voltage fluctuations\r\n- Allows safe shutdown during power failures\r\n- Protects files and operating system from corruption\r\n\r\n## 📝 6. Preventive Measures\r\n\r\n### Virus Prevention\r\n- Stop using pirated software\r\n- Install reliable antivirus software\r\n- Scan computer regularly for viruses\r\n- Install latest security patches\r\n- Avoid suspicious email attachments\r\n- Use trusted websites for downloads\r\n\r\n### General Security Best Practices\r\n- Keep software updated\r\n- Use strong passwords\r\n- Regular data backups\r\n- Enable automatic updates\r\n- Be cautious with email attachments\r\n- Use secure networks\r\n\r\n## 📋 7. Complete Exercise Solutions\r\n\r\n### 1. Answer the following questions:\r\n\r\n**a. What is meant by Computer Security?**\r\n\r\n**Answer:** Computer Security is the protection of computer data, information, programs, and hardware from malicious attackers and accidental harm.\r\n\r\n**b. What is computer Security threat? List its types.**\r\n\r\n**Answer:** Computer Security threat is anything that causes loss or corruption of data, information, software, or physical damage to computer hardware. Its types are:\r\n- Physical threats\r\n- Non-physical threats\r\n\r\n**c. What is malicious code? List any two examples.**\r\n\r\n**Answer:** Malicious code is harmful computer code intended to cause undesired effects or damage to a computer system. Examples:\r\n- Computer viruses\r\n- Worms\r\n\r\n**d. What is computer virus? List any two destruction tasks.**\r\n\r\n**Answer:** Computer virus is a destructive program that disturbs normal functioning of a computer system. Destruction tasks:\r\n- Display unnecessary messages and images\r\n- Run unwanted programs\r\n\r\n**e. What are the routes of computer virus transmission?**\r\n\r\n**Answer:** Routes of virus transmission:\r\n- Using pirated software\r\n- Sharing infected portable storage devices\r\n- Downloading files from unreliable websites\r\n- Exchanging data on networks\r\n- Opening virus-infected emails\r\n\r\n**f. List any four symptoms of computer viruses.**\r\n\r\n**Answer:** Symptoms of computer viruses:\r\n- Changes in size of files\r\n- Missing files or folders\r\n- Unusual error messages appearing\r\n- Programs hang frequently\r\n\r\n**g. Write four preventive ways to protect computer system from viruses.**\r\n\r\n**Answer:** Preventive measures:\r\n- Stop using pirated software\r\n- Install antivirus software\r\n- Scan computer regularly for viruses\r\n- Install latest security patch programs\r\n\r\n**h. Define computer worm and trojan horse.**\r\n\r\n**Answer:** \r\n- **Computer Worms:** Malicious code that doesn\'t hide in files and spreads from computer to computer through email, internet, and portable storage.\r\n- **Trojan Horse:** Destructive program that pretends to be useful but performs malicious actions.\r\n\r\n**i. What is information security? What does it do?**\r\n\r\n**Answer:** Information Security is protection of data, information, and software from being lost or damaged due to accidental or intentional harm. It controls and prevents unauthorized access to data and information.\r\n\r\n**j. List any four data and software security measures.**\r\n\r\n**Answer:** Security measures:\r\n- Firewall\r\n- Antivirus software\r\n- Authentication systems (Password and Biometric)\r\n- Backing up data and software\r\n\r\n### 2. Write appropriate technical terms:\r\n\r\n| Description | Technical Term |\r\n|-------------|----------------|\r\n| Securing computer data from malicious attackers | Computer Security |\r\n| Anything that can cause harm to data/software | Security Threat |\r\n| Harmful computer code causing damage | Malicious Code |\r\n| Destructive program that hides in host files | Computer Virus |\r\n| Destructive program that doesn\'t hide but replicates | Computer Worms |\r\n| Destructive program that doesn\'t replicate | Trojan Horse |\r\n| Process of identifying authorized users | Authentication |\r\n| Secret word providing system access | Password |\r\n| Device reading biometric information | Biometric |\r\n| Making data unreadable to unauthorized users | Cryptography |\r\n| Converting encrypted text to original form | Decryption |\r\n| Security barrier protecting from external threats | Firewall |\r\n| Making extra copy of data | Backup |\r\n| Device protecting from voltage fluctuations | Power Protection Device |\r\n| Device providing backup electric power | UPS |\r\n\r\n### 3. True/False Answers:\r\n\r\na. Data in disk cannot be damaged - **False**\r\nb. Malicious code includes viruses, worms, trojans - **True**\r\nc. Malicious website installs malware - **True**\r\nd. Password prevents unauthorized access - **True**\r\ne. Biometric locker prevents authorized person entry - **False**\r\nf. Converting non-readable to readable is encryption - **False**\r\ng. Hardware firewall blocks harmful internet data - **True**\r\nh. Antiviruses are harmful programs - **False**\r\ni. Regular maintenance detects hardware problems - **True**\r\nj. Dust particles can damage hard disk - **True**\r\nk. Volt guard supplies backup power during load shedding - **False** (UPS does this)\r\n\r\n### 4. Full Forms:\r\n\r\n- **FAT** = File Allocation Table\r\n- **MALWARE** = Malicious Software\r\n- **DDOS** = Distributed Denial of Service\r\n- **SMPS** = Switched Mode Power Supply\r\n- **CVT** = Constant Voltage Transformer\r\n- **UPS** = Uninterruptible Power Supply\r\n- **PSU** = Power Supply Unit\r\n- **CCTV** = Closed Circuit Television\r\n\r\n### 5. Multiple Choice Answers:\r\n\r\na. Data corruption causes: **iv. All of the above**\r\nb. Physical threat includes: **iii. Stealing a computer**\r\nc. Not malicious code: **iii. Kaspersky**\r\nd. Computer virus is: **i. Malware**\r\ne. Computer viruses can: **iv. All of the above**\r\nf. Virus spread through: **iv. All of the above**\r\ng. Information security measure: **i. Firewall**\r\nh. Antivirus software: **iii. Kaspersky**\r\ni. Backup power supplier: **iv. UPS**\r\nj. Monitors online activities: **ii. Spyware**\r\nk. Technique to steal credentials: **i. Phishing**\r\n\r\n### 6. Matching:\r\n\r\n- **Spam** → Unwanted advertisement messages\r\n- **Browser Hijack** → Shows unwanted advertisements on browser\r\n- **Scareware** → Shows fake virus alerts\r\n- **Worm** → Makes network slow\r\n\r\n## ✅ 8. Chapter Checklist & Exam Tips\r\n\r\n**Exam Hotspots 🔥:**\r\n\r\n- **Definitions**: Know exact definitions of computer security, malware types, and security measures\r\n- **Security Threats**: Understand difference between physical and non-physical threats\r\n- **Malware Types**: Be clear about viruses, worms, and trojans - their differences and characteristics\r\n- **Prevention Methods**: Memorize virus prevention techniques and security measures\r\n\r\n**Your Pre-Exam Checklist:**\r\n\r\n- [ ] I can define computer security and its importance\r\n- [ ] I can differentiate between physical and non-physical threats\r\n- [ ] I understand all types of malicious code (viruses, worms, trojans)\r\n- [ ] I know virus transmission routes and prevention methods\r\n- [ ] I can explain information security measures (firewall, antivirus, etc.)\r\n- [ ] I understand hardware security and power protection devices\r\n- [ ] I can identify symptoms of virus infection\r\n\r\n**Memory Tips:**\r\n- **Virus vs Worm vs Trojan**: Virus hides, Worm spreads, Trojan tricks\r\n- **Authentication methods**: Something you know (password), something you are (biometric)\r\n- **Power devices**: UPS for backup power, Stabilizer for steady voltage\r\n\r\n## 🎊 Conclusion\r\n\r\nComputer Security is not just about installing antivirus software - it\'s about developing a security mindset. In our increasingly digital world, understanding these concepts will help you protect not just your school projects, but also your future digital assets and professional data.\r\n\r\nRemember: A secure computer is like a well-protected house - it needs multiple layers of security, regular maintenance, and constant vigilance.\r\n\r\n**Key to Success:** Understand Real-World Applications + Memorize Key Definitions + Practice Identifying Threats = Top Security Marks!', 1, '2025-07-25 01:11:38', '2025-09-16 15:20:38'),
(100, 13206, '# Ethical and Social Issues in ICT - Grade 10 Notes\r\n\r\n## Complete Chapter Notes with All Exercises - NEB Curriculum\r\n\r\n## 🎯 Chapter Overview\r\n\r\nImagine if someone could steal your identity, read your private messages, or use your photos without permission - all through the internet. Welcome to the digital age, where technology brings amazing opportunities but also creates new challenges and responsibilities.\r\n\r\nThis chapter explores the ethical dilemmas and social issues that arise from our increasing dependence on Information and Communication Technology (ICT). From understanding your digital footprint to protecting yourself from cybercrime, you\'ll learn how to be a responsible digital citizen in an interconnected world.\r\n\r\nUnderstanding these concepts is not just about passing exams - it\'s about navigating the digital world safely and ethically throughout your life.\r\n\r\n**Weightage:** 6-8 marks in SEE examination  \r\n**Time Required:** 10-12 periods\r\n\r\n## 📚 Learning Objectives\r\n\r\nAfter studying this chapter, you will be able to:\r\n\r\n- Define ICT and understand its objectives and impact on society\r\n- Explain social media platforms and practice safe usage\r\n- Understand Electronic Transaction Act (ETA) and its provisions\r\n- Recognize various types of cybercrimes and their prevention\r\n- Understand digital citizenship and ethical behavior online\r\n- Explain intellectual property rights in the digital age\r\n- Use digital signatures and understand digital footprints\r\n\r\n## 💻 1. Introduction to ICT\r\n\r\n**ICT (Information and Communication Technology)** is a technology concerned with storage, retrieval, manipulation, and transmission of information electronically in digital form.\r\n\r\n### Key Components of ICT\r\n- **Information**: Data processed into meaningful form\r\n- **Communication**: Exchange of information between users\r\n- **Technology**: Tools and systems that enable digital processes\r\n\r\n### Four Main Objectives of ICT\r\n\r\n| Objective | Description |\r\n|-----------|-------------|\r\n| **Good Governance** | Promote transparency and efficiency in administration through ICT |\r\n| **Human Resource Development** | Develop skilled professionals in the ICT field |\r\n| **Accessibility** | Make information technology affordable and accessible to all people |\r\n| **Infrastructure Development** | Develop and expand ICT infrastructure nationwide |\r\n\r\n## 📱 2. Social Media\r\n\r\n**Social Media** consists of websites and applications that enable people to interact with each other by sharing content quickly and efficiently on the internet.\r\n\r\n### Popular Social Media Platforms\r\n\r\n| Platform | Primary Function | User Base |\r\n|----------|------------------|-----------|\r\n| **Facebook** | Social networking, sharing updates | General public |\r\n| **Twitter** | Microblogging, news sharing | News, opinions |\r\n| **Instagram** | Photo and video sharing | Visual content |\r\n| **YouTube** | Video sharing and streaming | Entertainment, education |\r\n| **LinkedIn** | Professional networking | Career-focused |\r\n| **TikTok** | Short video sharing | Entertainment |\r\n\r\n### Four Ways to Stay Safe on Social Media\r\n\r\n#### 1. Strong Password Security\r\n- Use complex passwords with letters, numbers, and symbols\r\n- Change passwords monthly\r\n- Don\'t share passwords with anyone\r\n- Use different passwords for different accounts\r\n\r\n#### 2. Privacy Settings\r\n- Don\'t set up automatic login on devices\r\n- Review and adjust privacy settings regularly\r\n- Limit who can see your posts and personal information\r\n- Be cautious about location sharing\r\n\r\n#### 3. Communication Ethics\r\n- Use polite and respectful language\r\n- Think before you post - content can be permanent\r\n- Avoid sharing controversial or offensive content\r\n- Report cyberbullying or harassment\r\n\r\n#### 4. Meeting Safety\r\n- **Never meet online friends alone**\r\n- If meeting is necessary, bring a trusted friend\r\n- Meet in public places\r\n- Inform family members about meetings\r\n\r\n### Social Media Benefits and Risks\r\n\r\n**Benefits:**\r\n- Global connectivity and communication\r\n- Access to information and news\r\n- Educational resources and opportunities\r\n- Business and marketing platforms\r\n\r\n**Risks:**\r\n- Privacy invasion and data theft\r\n- Cyberbullying and harassment\r\n- Addiction and time wasting\r\n- Spread of misinformation\r\n\r\n## ⚖️ 3. Electronic Transaction Act (ETA)\r\n\r\nThe **Electronic Transaction Act** is Nepal\'s cyber law that legalizes transactions through electronic media and provides a legal framework for digital activities.\r\n\r\n### Four Major Advantages of ETA\r\n\r\n1. **Fraud Control**: Helps control and stop various types of electronic frauds\r\n2. **Criminal Punishment**: Provides legal basis to punish cyber criminals\r\n3. **Legal Transactions**: Legalizes transactions through electronic media\r\n4. **Network Services**: Provides provisions for network service regulation\r\n\r\n### Four Key Objectives of ETA\r\n\r\n1. **Punish Cyber Criminals**: Establish legal penalties for cyber crimes\r\n2. **Secure Transactions**: Make electronic transactions reliable and secure\r\n3. **Legalize E-Commerce**: Provide legal recognition to electronic transactions\r\n4. **Digital Signature Control**: Create, control, and verify digital signatures\r\n\r\n### Four Main Provisions of ETA\r\n\r\n| Provision | Description |\r\n|-----------|-------------|\r\n| **Network Service** | Regulations for internet service providers |\r\n| **Digital Signature** | Legal acceptance of digital signatures and electronic records |\r\n| **Cyber Crime Punishment** | Penalties for various cyber crimes |\r\n| **Judicial Body Formation** | Establishment of courts to handle cyber cases |\r\n\r\n### Why Cyber Law is Necessary in Nepal\r\n\r\n- **Combat Cyber Crimes**: Address hacking, online fraud, and digital theft\r\n- **Control Internet Misuse**: Prevent abuse of computer and internet resources\r\n- **Legal Framework**: Provide clear guidelines for digital transactions\r\n- **Protect Citizens**: Safeguard people from digital exploitation\r\n- **Economic Growth**: Enable safe digital commerce and e-governance\r\n\r\n## 🔐 4. Digital Security Concepts\r\n\r\n### A. Digital Signature\r\n\r\n**Digital Signature** is a security mechanism used on the internet for digital data processing and transactions through electronic media.\r\n\r\n**How It Works:**\r\n- Uses two keys: Public key and Private key\r\n- Private key for signing documents\r\n- Public key for verification\r\n- Ensures document authenticity and integrity\r\n\r\n**Benefits:**\r\n- Non-repudiation (can\'t deny signing)\r\n- Authentication (verifies identity)\r\n- Data integrity (detects tampering)\r\n- Legal validity in electronic transactions\r\n\r\n### B. Digital Footprint\r\n\r\n**Digital Footprint** is the data traces of all online activities that a person performs while using the Internet.\r\n\r\n#### Types of Digital Footprints\r\n\r\n| Type | Description | Examples |\r\n|------|-------------|----------|\r\n| **Active Footprint** | Deliberately shared information | Social media posts, comments, uploads |\r\n| **Passive Footprint** | Automatically collected data | Website visits, IP addresses, cookies |\r\n\r\n#### Three Main Uses of Digital Footprints\r\n\r\n1. **Activity Tracking**: Monitor and track user\'s online activities\r\n2. **Character Assessment**: Show interests and behavioral patterns of users\r\n3. **Legal Evidence**: Used by law enforcement for character assessment and investigations\r\n\r\n#### Managing Your Digital Footprint\r\n- Think before posting anything online\r\n- Use privacy settings on social platforms\r\n- Regularly audit your online presence\r\n- Be aware that deleted content may still exist\r\n\r\n## 🚨 5. Cyber Crimes\r\n\r\n**Cyber Crime** refers to crimes committed with the help of computers and the internet.\r\n\r\n### Common Types of Cyber Crimes\r\n\r\n| Crime Type | Description | Impact |\r\n|------------|-------------|---------|\r\n| **Hacking** | Unauthorized access to computer systems | Data theft, system damage |\r\n| **Online Fraud** | Deceiving people for financial gain | Financial loss, identity theft |\r\n| **Cyber Bullying** | Harassment through digital platforms | Emotional trauma, depression |\r\n| **Cyber Stalking** | Repeated harassment using internet services | Psychological harm, fear |\r\n| **Email Bombing** | Sending massive emails to crash systems | System disruption, resource waste |\r\n| **Phishing** | Stealing personal information through fake websites | Identity theft, financial loss |\r\n| **Software Piracy** | Illegal copying and distribution of software | Economic loss, legal issues |\r\n| **Data Theft** | Stealing or destroying data and files | Information loss, privacy violation |\r\n\r\n### Penalties Under Nepal\'s ETA\r\n\r\n| Crime | Maximum Imprisonment |\r\n|-------|---------------------|\r\n| **Software Piracy/Code Alteration** | 3 years |\r\n| **Publishing Prohibited Content** | 4 years |\r\n| **General Cyber Crimes** | Varies by severity |\r\n\r\n### Preventing Cyber Crimes\r\n\r\n**Individual Level:**\r\n- Use strong passwords and two-factor authentication\r\n- Keep software updated\r\n- Be cautious with email attachments\r\n- Don\'t share personal information online\r\n- Use reputable antivirus software\r\n\r\n**Organizational Level:**\r\n- Implement cybersecurity policies\r\n- Regular security training for employees\r\n- Network monitoring and firewalls\r\n- Regular security audits\r\n- Incident response plans\r\n\r\n## 👤 6. Digital Citizenship\r\n\r\n**Digital Citizenship** refers to the responsibilities and duties of a digital citizen in a digital community.\r\n\r\n### Key Principles of Digital Citizenship\r\n\r\n#### 1. Digital Etiquette\r\n- Be respectful and polite online\r\n- Follow community guidelines\r\n- Avoid offensive language or behavior\r\n- Respect others\' opinions and privacy\r\n\r\n#### 2. Digital Literacy\r\n- Understand how to use technology effectively\r\n- Evaluate online information critically\r\n- Protect personal and others\' privacy\r\n- Recognize and avoid fake news\r\n\r\n#### 3. Digital Rights and Responsibilities\r\n- Right to privacy and free expression\r\n- Responsibility to respect others\' rights\r\n- Follow laws and regulations\r\n- Report inappropriate behavior\r\n\r\n#### 4. Digital Health and Wellness\r\n- Balance online and offline activities\r\n- Take regular breaks from screens\r\n- Be aware of digital addiction signs\r\n- Maintain physical and mental health\r\n\r\n## 📚 7. Intellectual Property Rights\r\n\r\n**Intellectual Property** means the property that deals with creations of authors, artists, musicians, and inventors.\r\n\r\n### Types of Intellectual Property\r\n\r\n| Type | Description | Examples |\r\n|------|-------------|----------|\r\n| **Copyright** | Protects original works of authorship | Books, music, software, videos |\r\n| **Patents** | Protects inventions and innovations | New technologies, processes |\r\n| **Trademarks** | Protects brand names and logos | Company logos, brand names |\r\n| **Trade Secrets** | Protects confidential business information | Formulas, customer lists |\r\n\r\n### Digital Age Challenges\r\n- Easy copying and distribution of digital content\r\n- Difficulty in tracking and preventing piracy\r\n- Global nature makes enforcement complex\r\n- Balance between protection and fair use\r\n\r\n## 📋 8. Complete Exercise Solutions\r\n\r\n### 1. Answer the following questions:\r\n\r\n**a. What is ICT?**\r\n\r\n**Answer:** Information and Communication Technology is a technology concerned with storage, retrieval, manipulation, and transmission of information electronically in digital form.\r\n\r\n**b. What is social media? List any four social medias.**\r\n\r\n**Answer:** Social media consists of websites and applications that enable people to interact with each other by sharing content quickly and efficiently on the internet. Four social media platforms:\r\n- YouTube\r\n- Instagram  \r\n- Facebook\r\n- Twitter\r\n\r\n**c. List any four advantages of ETA.**\r\n\r\n**Answer:** Advantages of ETA:\r\n- Helps control and stop various types of electronic frauds\r\n- Provides legal basis to punish cyber criminals  \r\n- Legalizes transactions through electronic media\r\n- Has provisions for network services\r\n\r\n**d. List any four ways that help you stay safe on social media.**\r\n\r\n**Answer:** Ways to stay safe on social media:\r\n- Use strong passwords and change them monthly\r\n- Don\'t share passwords with anyone\r\n- Use polite words when communicating\r\n- Don\'t set up automatic login on devices\r\n\r\n**e. What is digital signature?**\r\n\r\n**Answer:** Digital Signature is a security mechanism used on the internet for digital data processing and transactions through electronic media.\r\n\r\n**f. Define Digital footprint. Write its usage.**\r\n\r\n**Answer:** Digital footprint is the data traces of all online activities that a person performs while using the Internet. Uses:\r\n- Track user\'s online activities\r\n- Show interests and character of users  \r\n- Used by law enforcement for character assessment\r\n\r\n**g. List any four ICT objectives.**\r\n\r\n**Answer:** ICT objectives:\r\n- Promote good governance through ICT use\r\n- Develop human resources in ICT field\r\n- Make information technology affordable and accessible\r\n- Develop and expand ICT infrastructure\r\n\r\n**h. What is cyber crime? List any four cyber crimes.**\r\n\r\n**Answer:** Cyber crimes are crimes committed with the help of computers and internet. Four cyber crimes:\r\n- Cyber bullying\r\n- Online fraud\r\n- Cyber stalking  \r\n- Email bombing\r\n\r\n**i. What is intellectual property?**\r\n\r\n**Answer:** Intellectual Property means property that deals with creations of authors, artists, musicians, and inventors.\r\n\r\n**j. Write any four provisions in Electronic Transaction Act.**\r\n\r\n**Answer:** ETA provisions:\r\n- Provision of Network Service\r\n- Provision of punishment on cyber crime\r\n- Provision of duties and responsibilities of subscribers  \r\n- Provision of legal acceptance of digital signatures\r\n\r\n**k. Write any four objectives of ETA.**\r\n\r\n**Answer:** ETA objectives:\r\n- Punish cyber criminals\r\n- Make transactions reliable and secure\r\n- Legalize transactions through electronic media\r\n- Control, create, and verify digital signatures\r\n\r\n**l. Why is cyber law necessary in Nepal?**\r\n\r\n**Answer:** Cyber law is necessary in Nepal because it helps deal with cyber crimes like hacking and online fraud. It controls misuse of computers and internet, and helps punish cyber criminals.\r\n\r\n### 2. Write Technical terms:\r\n\r\n| Description | Technical Term |\r\n|-------------|----------------|\r\n| Website enabling people to interact by sharing content | Social Media |\r\n| Stealing personal information in social media | Phishing |\r\n| Responsibilities of digital citizen in digital community | Digital Citizenship |\r\n| Data traces of online activities | Digital Footprint |\r\n| Crime committed with computer help | Cyber Crime |\r\n| Stealing or destroying data and files | Cyber Crime |\r\n| Repeated harassment using internet services | Cyber Stalking |\r\n| Law legalizing electronic transactions | Electronic Transaction Act |\r\n\r\n### 3. Full Forms:\r\n\r\n- **ICT** = Information and Communication Technology\r\n- **ETA** = Electronic Transaction Act  \r\n- **ATM** = Automated Teller Machine\r\n\r\n### 4. Multiple Choice Answers:\r\n\r\na. Social media platform: **i. Facebook**\r\nb. Internet activities: **iv. All of the above**\r\nc. Meeting Facebook friend alone: **iv. Don\'t meet him**\r\nd. Not a cybercrime: **i. Authentication**\r\ne. Cyber law deals with: **iv. All of the above**  \r\nf. Nepal\'s cyber law provisions: **iv. All of the above**\r\ng. Nepal\'s cyber law known as: **ii. Electronic Transaction Law**\r\nh. Software piracy imprisonment: **iii. 3 years**\r\ni. Prohibited content imprisonment: **iv. 4 years**\r\n\r\n### 5. Matching:\r\n\r\n- **Decryption** → Converting encrypted data back to original form\r\n- **Digital Signature** → Security mechanism using public and private keys  \r\n- **Hacking** → Stealing data and controlling computer systems\r\n- **Digital Citizenship** → Responsibilities of digital citizens in digital community\r\n\r\n## ✅ 9. Chapter Checklist & Exam Tips\r\n\r\n**Exam Hotspots 🔥:**\r\n\r\n- **ICT Definition and Objectives**: Core concepts frequently tested\r\n- **Social Media Safety**: Practical tips and safety measures\r\n- **ETA Advantages and Provisions**: Key legal framework knowledge  \r\n- **Cyber Crimes Types**: Classification and examples\r\n- **Digital Concepts**: Signatures, footprints, citizenship\r\n\r\n**Your Pre-Exam Checklist:**\r\n\r\n- [ ] I can define ICT and list its four main objectives\r\n- [ ] I know four major social media platforms and safety measures\r\n- [ ] I understand ETA advantages, objectives, and provisions  \r\n- [ ] I can identify different types of cyber crimes\r\n- [ ] I understand digital citizenship responsibilities\r\n- [ ] I can explain digital signatures and digital footprints\r\n- [ ] I know the penalties under Nepal\'s cyber law\r\n\r\n**Memory Tips:**\r\n- **ICT Objectives**: **G**ood governance, **H**uman resources, **A**ccessibility, **I**nfrastructure (GHAI)\r\n- **Social Media Safety**: **P**assword, **P**rivacy, **P**oliteness, **P**ublic meetings (4 P\'s)\r\n- **ETA Benefits**: **F**raud control, **C**riminal punishment, **L**egal transactions, **N**etwork services\r\n\r\n## 🎊 Conclusion\r\n\r\nIn our digital world, being technologically literate isn\'t enough - we must also be ethically aware and socially responsible. The concepts in this chapter will help you navigate the digital landscape safely while respecting others\' rights and contributing positively to the digital community.\r\n\r\nRemember: Technology is a tool that amplifies human behavior - use it wisely, ethically, and responsibly.\r\n\r\n**Key to Success:** Understand Real-World Applications + Know Legal Framework + Practice Digital Ethics = Excellence in ICT Ethics!', 1, '2025-07-25 01:11:38', '2025-09-16 15:20:38');
