Question:
Consider a circular ring of radius $\mathrm{r}$, uniformly charged with linear charge density. Find the electric potential at a point on the axis at a distance $x$ from the centre of the ring. Using this expression for the potential, find the electric field at this point.
Solution:
$\mathrm{E}=\frac{\mathrm{r} \lambda \mathrm{x}}{2 \mathrm{e}_{0}\left(\mathrm{r}^{2}+\mathrm{x}^{2}\right)^{3 / 2}}$