1. The problem statement, all variables and given/known data An infinitely long, hollow, conducting cylinder has a inner radius a and outer radius b and carries a linear charge density λ along its length. What is the electric field everywhere? 2. Relevant equations ∫E⋅dA = Qenc/∈ Variables ∈ = permittivity constant a = inner radius b = outer radius λ = linear charge density E = electric field r = distance to point of E field Qenc = enclosed charge 3. The attempt at a solution For inside (r∠a) and in the shell (a∠r∠b) the electric field is zero. I don't know what to do for outside the shell. I think the charge is concentrated on the outer shell just as for a spherical conductor, is this true? Here is my attempt for outside.