1. The problem statement, all variables and given/known data A ring charge of total charge Q and radius a is concentric with a grounded conducting sphere of radius b, b < a. Determine the potential everywhere. The ring is located in the equatorial plane, so both the sphere and the ring have their center at the same spot. 2. Relevant equations ∇V=0 3. The attempt at a solution Well the region r < b is V = 0. At first I thought about using the Laplace equatio for he next zone (b < r < a) making it zero on the surface of the sphere and Q/4πε on the ring, but then I am at a draw and don't know what to do next.