1. The problem statement, all variables and given/known data Find the electric potential V and electric field E at the point P due to a line of linear charge density = λ 2. Relevant equations E = (2kλ)/z 3. The attempt at a solution Now I made these lines If P is on the z axis, r' = x, but it's shifted, so r' = x-x', and r = z, so then | r - r' | = ((x-x')^2+z^2)^1/2 The dl' = λdx, and -L < x < L So we use the equation V(r), where k and λ are constants, and integration is from -L to L So V(z) = kλ ∫ dx / ((x-x')^2+z^2)^1/2 , from -L to L Am I correct? And as for the the E field, I think it's simply E = (2kλ)/z ?