question_answer 32)

                  A proton is kept at rest. A position charged particle is released from rest at a distance d in its field. Consider two experiments; one in which die charged particle is also a proton and in another, a positron. In the same time t, the work done oil the two moving charged particles is                 (a) same as the same force law is involved in die two experiments.                 (b) less for the case of a positron, as the positron moves away more rapidly and the force oil it weakens.                 (c) more for die case of a positron, as die positron moves away a larger distance.                 (d) same as the work done by charged particle oil the stationary proton.                

Answer:

                  (c) Work = Force x distance                 Positron is lighter than proton, so it travels large distance.