Q 1.24(c): Two large, thin metal plates are parallel and close to each other. On their inner faces, the plates have surface charge densities of opposite signs and of magnitude . What is E:(c) between the plates?
We know, electric field, E, due to an infinite plate (length>>thickness) having surface charge density = .
(To note: It's independent of distance from the plate!)
Let A and B be the two plates such that:
=
= -
Therefore,
The electric field between the plates, E = =