Question

A point charge $q$ is rotated along a circle in the electric field generated by another point charge $Q$. The work done by the electric field on the rotating charge in one complete revolution is

• A. zero
• B. positive
• C. negative
• D. zero if the charge $Q$ is at the centre and nonzero otherwise

Answer 1

Answer: (A)

Work done in displacement of charge, $W=q\Delta V$
where $\Delta V$ = potential difference between the displacement of charge
Hence, work done in complete rotation is zero.