Conductors and co-axial cables!?? Say you have a long conducting hollow cylinder with some surface charge density [itex]\rho[/itex] which is inside another hollow (uncharged) cylinder. What would the electric field be outside the outer cylinder? I am guessing that the e-field outside the outer cylinder should be zero because the inner cylinder would produce induced charges on the surface of the outer cylinder equal but opposite in magnitude and therefore the total charge enclosed in both of the cylinders would be zero. Is this correct?