The radius of the circular path is given by r = mv/qB. Since kinetic energy K = (1/2)mv², momentum p = mv = √(2mK). Thus, r = √(2mK) / qB. Since K, q, and B are the same for both, r ∝ √m. Therefore, rₑ/rₚ = √(mₑ/mₚ).