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 in which the charged particles is also a proton and in another, a positron. In the same time t, the work done on the two moving charged particles is a) the 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 from a larger distance d) same as the work done by charged particle on the stationary proton
Force between two protons = force between a proton and a positron. As positron is much lighter than proton, it moves away a larger distance compared to proton. As work done =force×distance, therefore in the same time t, work done in case of positron is more than that in case of proton. option c is correct answer
