How is electric flux related to the electric field E? How is the total electric flux over a closed surface related to the charge enclosed within the surface? A thin spherical shell of radius R1 carries a total charge Q1 that is uni- formly distributed on its surface. A second, larger concentric thin shell of radius R2 carries a charge Q2 also uniformly distributed over the surface of the shell. Use Gauss' law to find the electric field in the regions. (a) r < R1, (b) R1 < r < R2 , and (c) R2 < r . The electric charges are such that Q1 > 0 and the electric field is zero for r > R2 . Find the ratio Q1/Q2 .