2.2E: Potential on the Axis of a Charged Ring

The field on the axis of a charged ring is given in section 1.6.4. The reader is invited to show that the potential on the axis of the ring is

\[V=\frac{Q}{4\pi\epsilon_0 (a^2+x^2)^{1/2}}.\tag{2.2.8}\]

You can do this either by integrating the expression for the field or just by thinking about it for a few seconds and realizing that potential is a scalar quantity.