pkysics problem?

Question

Concentric conducting spherical shells carrying charges Q and -Q, respectively. The inner shell has neglligible thickness. Determine the electric field (a) less than a (b) between b and c (c) greater than c (d) what is the potential difference between the shell?

Answer 1

Let me guess that a is the radius of the inner shell, b is the inner radius of the outer shell, and c is the outer radius of the outer shell. Using Gauss's Law:
(a) E(r (b) E(b (c) E (r>c) = 0 (same reason as for (b))
(d) E(a P(a