PHYSICS · Single correct · CBSE · Physics · Electrostatic Potential and Capacitance · Electrostatic Potential and Capacitance
Problem
Two isolated point charges, +q and −q, are released from rest very far apart and allowed to move only under their mutual interaction. Which of the following statements best explains how their kinetic energies change as they approach each other?
(a) Their total kinetic energy remains zero because the opposite charges neutralize each other’s energy changes.
(b) Only the positive charge gains kinetic energy while the negative charge loses the same amount, so the total kinetic energy stays constant.
(c) Their total kinetic energy increases because the electric force does positive work, converting electric potential energy into kinetic energy.
(d) Their total kinetic energy decreases as they approach because the attractive force does negative work on them.