A non-conducting solid sphere of radius R is uniformly charged. The magnitude of the electric field due to the sphere at a distance r from its centre :

For a uniformly charged non-conducting sphere, with increasing distance from the centre $\left(\mathrm{r}\right)$, the magnitude of electric field first increases linearly from zero to maximum for $0\le \mathrm{r}\le \mathrm{R}$ and then decreases according to inverse-square law for $\mathrm{R}<\mathrm{r}<\infty$.