Question

When the separation between two charges is increased, the electric potential energy of the charges
(a) increases
(b) decreases
(c) remains the same
(d) may increase or decrease

Answer 1

(d) may increase or decrease

The electric potential energy, E, between the two charges, q₁ and q₂, separated by the distance, r, is given as
$$\begin{gathered} E=k\frac{q_1{q}_2}{r}, \\ \mathrm{where}k=\mathrm{constant} \end{gathered}$$
As the distance between the charges is increased, the energy will decrease if both the charges are of similar nature. But if the charges are oppositely charged, the energy will become less negative and, hence, will increase.