1. The problem statement, all variables and given/known data I have a conceptual question. If there are two parallel infinite planes with charge densities of -sigma and +sigma, would the E feild between them really be constant? 2. Relevant equations E=sigma/(2*epsilon_0) (K*q_0*Q)/r^2 3. The attempt at a solution There is an example in my book that asks for the E feild in between the two planes, and it is solved under the assumption that the E feild remains the same regardless of the distance from either plane as long as it is within the two planes. Is this done for simplicity or is it done that way because that is how it is in reality? Because when I look at it I think of the electric feild and electric force as varying with r.