A hollow conducting sphere of radius R has a charge ( +Q) . on its surface. What is the electric potential within the sphere at a distance $\mathrm{r}=\frac{\mathrm{R}}{3}$ from its centre?

• A

  Zero

• B

  $\frac{1}{4{\mathrm{\pi \epsilon }}_0}\frac{\mathrm{Q}}{\mathrm{r}}$

• C

  $\frac{1}{4{\mathrm{\pi \epsilon }}_0}\frac{\mathrm{Q}}{\mathrm{R}}$

• D

  $\frac{1}{4{\mathrm{\pi \epsilon }}_0}\frac{\mathrm{Q}}{{\mathrm{r}}^2}$