#### Potential from a Ring of Charge

Case 1: A point charge Q is placed a distance a from the origin on the +y axis.

Case 2: A total charge Q is spread uniformly over a ring of radius a that lies in the y-z plane.

Consider a point a distance x along the x-axis. In which case is the magnitude of the electric field greater?

- Case 1
- Case 2
- neither, they're equal

In which case is the magnitude of the electric potential greater?

- Case 1
- Case 2
- neither, they're equal

Potential is a scalar, so all that matters for potential is that in both cases the charge is the same distance (x^{2} + a^{2})^{1/2} from the point. In both cases, then, the potential is given by:

V(x) = kQ/(x^{2} + a^{2})^{1/2}