Question

The work done in carrying a charge $q$ once round a circle of radius $r$ with a charge $Q$ at the centre is :

• A. $\frac{qQ}{4\pi {\epsilon }_{0}r}$
• B. $\frac{qQ}{4\pi {\epsilon }_0^2{r}^2}$
• C. $\frac{qQ}{4\pi {\epsilon }_0{r}^2}$
• D. None of the above

Answer 1

Answer: (D)

None of the above

Work done $=$ force $\times$ displacement

The displacement will be zero for one complete circular round of charge $q$.

Thus, the work done will be zero.