Outside the spherical charge, the intensity of electric field at a point $P$ situated at a distance $r$ from the centre of the charge is
$E=\frac{1}{4 \pi \varepsilon_{0}} \frac{q}{r^{2}} (\text { if } r>R) $
On the surface of spherical charge the electric field is given by
$E=\frac{1}{4 \pi \varepsilon_{0}} \frac{q}{r^{2}}$ (if $ r=R )$
and inside the spherical charge the electric field is
$E=\frac{1}{4 \pi \varepsilon_{0}} \frac{q r}{R^{3}} $ (if $ r < R)$
Hence, the variation of $E-r$ is a follows :
