1. The problem statement, all variables and given known data. A metal sphere with radius r_a is supported on an insulating stand at the center of a hollow, metal spherical shell with radius r_b. There is charge + q on the inner sphere and charge - q on the outer spherical shell. Take the potential V to be zero when the distance r from the center of the spheres is infinite. Calculate the potential V(r) for r < r_a. (Hint: The net potential is the sum of the potentials due to the individual spheres.) 2. Relevant equations E=Kq/r^2 and integrating with respect to r 3. The attempt at a solution I'm thinking that since this is a conductor, the net charge inside the smaller metal sphere will be zero. Since the net charge inside the conductor is zero, the electric field will be zero and if that is zero then there can't be a voltage right?