b
(b) \({V_{inside}} = \frac{Q}{{4\pi {\varepsilon _0}R}}\) for \(r \le R\) ....\((i)\)
and \({V_{out}} = \frac{Q}{{4\pi {\varepsilon _0}r}}\) for \(r \ge R\) ....\((ii)\)
i.e. potential inside the hollow spherical shell is constant and outside varies according to \(V \propto \frac{1}{r}\).