Two identical negative point charges are initially very far apart and are slowly…
PHYSICS · Single correct · CBSE · Physics · Electrostatic Potential and Capacitance · Electrostatic Potential and Capacitance
Problem
Two identical negative point charges are initially very far apart and are slowly brought to a separation of 0.20m. Which statement best describes the sign of the work that must be done by an external agent during this process?
(a) Negative, because the potential energy of two negative charges is negative and becomes more negative as they are brought closer.
(b) Zero, because the mutual repulsive forces on the two charges are equal and opposite at every instant, so no net external work is required.
(c) Positive, because the charges repel and the agent must supply energy to push them closer together.
(d) The sign of the work cannot be determined without knowing the magnitude of the charges and the exact path taken.