A point charge \(q\) is rotated along a circle in the electric field generated by another point charge \(Q\). The work done by the electric field on the rotating charge in one complete revolution is:

The energy density in the electric field created by a point charge falls off with the distance from the point charge as

1. \(1 \over r\)

2. \(1 \over r^2\)

3. \(1 \over r^3\)

4. \(1 \over r^4\)