1. The problem statement, all variables and given/known data An infinite cylindrical shell has inner radius 'a' and outer radius 'b'. The shell carries a charge density J(s) = Cs^2 + Ds. Where 'C' and 'D' are constants. Find B everywhere. 2. Relevant equations 3. The attempt at a solution My thought was to find the field do to the inner radius, the field do to outer radius, and then subtract inner from outer. Is this the correct thought process?