1. The problem statement, all variables and given/known data On the XY plane there exist two concentric, thin, conducting shells, centered at the origin; one is of radius R, the other of 2R. They are connected. There exists a point charge at (0, 1.5R). What is the potential at some point outside the outer ring? 2. Relevant equations I don't really understand what's going on here 3. The attempt at a solution Tried method of image charges for outer sphere, and inverse for inner sphere... didn't get anywhere. I'm trying to understand the general behavior of charges inside a void inside a conductor... I was told that given any conductor, with a void inside of it containing charge, the electric field outside of it will be the same irrespective of how you move the charge around.. I'd really appreciate an explanation!