(a)[3]
The electric potential at the surface of the sphere is $V_0$. On the axes of Fig. 5.1, sketch a graph to show how the electric potential due to the charged sphere varies with distance $x$, for values of $x$ from $x = 0$ to $x = 4r$.
(b)[3]
The electric field strength at the surface of the sphere is $E_0$. On the axes of Fig. 5.2, sketch a graph to show how the electric field strength due to the charged sphere varies with distance $x$, for values of $x$ from $x = 0$ to $x = 4r$.