a
\(\,8  \times \) નાના ટિપાઓનું કદ = મોટા ટિપાનુ કદ 

\(\,8\,\,\frac{4}{3}\,\,\pi {r^3}\,\, = \,\,\frac{4}{3}\,\,\pi {R^3}\,\, \Rightarrow \,\,2r\,\, = \,\,R\)

\({V_{tiny}}\,\, = \,\,\frac{{kq}}{r}\,\,\therefore \,\,{V_{big}}\,\, = \,\,\frac{{k\,\, \times \,\,8q}}{R}\,\, = \,\,\frac{{8kq}}{{2r}}\)

\({V_{big}}\,\, = \,\,4{V_{tiny}}\,\, = \,\,4\,\, \times \,\,10\,\, = \,\,40\,V\)