Question

Five equal charges each of value $q$ are placed at the corners of a regular pentagon of side $a$, what will be the electric field at centre $O$, if the charge from one of the corners (say $A$) is removed?

• A. $\frac{q}{4\pi {\epsilon }_0{r}^2}$ along $OA$
• B. $\frac{2q}{4\pi {\epsilon }_0{r}^2}$ along $OB$
• C. $\frac{q^2}{4\pi {\epsilon }_0{r}^2}$ along $OC$
• D. $\frac{2q}{4\pi {\epsilon }_0{r}^2}$ along $OA$

Answer 1

Answer: (A)

When a charge $q$ from corner $A$ is removed, electric field at $O$ is $E_1=\frac{q}{4\pi {\epsilon }_0{r}^2}$ aong $OA$