1. The problem statement, all variables and given/known data Two hollow concentric conducting spheres hold charges Q and Q as shown in the attachment. Find the potential of each sphere, and the potential difference. 2. Relevant equations Potential difference V = Phi - Phi 3. The attempt at a solution I'm having some trouble with the actual question; what does it mean, the potential of each sphere? Does this mean the potential of the sphere at a distance r where r is greater than the radius? In this case I think the answer would be Phi = Q/(4*Pi*Epsilon*r) and Phi = Q/(4*Pi*Epsilon*r) I don't think this is quite correct however. Does it mean the potential *on* each sphere instead? In this case, wouldn't the potential on the inner sphere due to the bigger sphere be zero? I'm quite confused here and any help would be appreciated!