(a) Two concentric spherical shell conductors carry equal and opposite charges. The inner shell has radius "a" and charge +q, and the outer shell has radius "b" and charge -q. Find the potential difference between the shells, Va-Vb, in terms of the given parameters and any constants.
(b) Two long, coaxial cylindrical shell conductors carry equal and opposite charges. The inner shell has radius "a" and charge +q, and the outer shell had radius "b" and charge -q. The length of each cylindrical shell is L. Find the potential difference between the shells, Va-Vb, in terms of the given parameters and any constants.