A proton is kept at rest. A positively charged particle is released from rest at a distance `d` in its field. Consider two experiments, one ini which the charged particle is also a proton and in another, a position. In the same time `t`, the work done on the two moving charged particles is

Options

A. same as the same force law is involved in the two experiments.
B. less for the case of a positron, as the positron moves away more rapidly and the force on it weakens.
C. more for the case of a positron, as the positron moves away a larger distance.
D. same as the work done by charged particle on the stationary proton.

Answer

C

Explanation

Force between two protons is same as that of between proton and a positron. As positron is much lighter than proton, it moves away through much larger distance compared to proton.
We know that work done = force `xx` distance. As forces are same in case of proton and positron is larger, hence, work done will be more.