Question

The work done to move a unit charge along an equipotential surface from P to Q:

• A. must be defined as $-{\int }_P^Q\overline{E}.\overline{dl}$
• B. is zero
• C. can have a non-zero value
• D. both (a) and (b) are correct

Answer 1

The correct option is D both (a) and (b) are correct

Work done to move a unit charge along an equipotential surface from $P$ to $Q$.
$W=-{\int }_P^Q\overrightarrow{E}.d\overrightarrow{l}$
On equipotential surface $\overrightarrow{E}\perp d\overrightarrow{l}$
$W=-{\int }_P^{Q}E\left(dl\right)\cos {90}^o=0$