A conducting sphere carrying a charge ‘q' has a radius ‘a'. It is inside a concentric hollow conducting sphere of inner radius ‘b' and outer radius ‘c'. The hollow sphere has no net charge. Calculate the electric field for: a) r < a; b) a < r < b; c) b < r < c; d) r > c; e) What is the charge on the inner surface of the hollow sphere? f) What is the charge on the outer surface?