Electric potential at centre of non conducting sphere of radius ‘R’ is ______ [q is charge in it $\mathrm{k}=\frac{1}{4{\mathrm{\pi \epsilon }}_0}$]

$$\begin{gathered} \mathrm{The} \mathrm{electric} \mathrm{potential} \mathrm{at} \mathrm{a} \mathrm{distance} \mathrm{r} \mathrm{from} \mathrm{the} \mathrm{center} \mathrm{of} \mathrm{a} \mathrm{sphere} \mathrm{of} \mathrm{radius} \mathrm{R} \mathrm{is}: \\ \mathrm{V} = \frac{\mathrm{kq}\left(3{\mathrm{R}}^2-{\mathrm{r}}^2\right)}{2{\mathrm{R}}^3} \\ \mathrm{at} \mathrm{the} \mathrm{centre}, \mathrm{r} = 0 \\ \mathrm{V} = \frac{3\mathrm{kq}}{2\mathrm{R}} \end{gathered}$$