1. The problem statement, all variables and given/known data From the picture attached it can be seen that there are two plates with charge density σa and -σb. We will chose → as the n direction. What is that electric field everywhere for this system? 2. Relevant equations ∫∫E.dS = ∫∫σ/ε0 dA 3. The attempt at a solution Using Gauss' law we can take three gaussian surfaces. One containing both of the plates and two more containing each individual plate. Using the surface containing both plates, we have: ESn + ESn = σ(a-b)/ε0 n hence, E = σ(a-b)/2ε0 n outside of the plates Inside I think I should use superposition of the two other surfaces. However I'm not sure which direction the electric field goes in for these two surfaces? Generally I'm not convinced by my answer and lack some understanding which I would like some help with. Thanks in advance!