Chapter 22, Problem 24P

(II) Two large, flat metal plates are separated by a distance that is very small compared to their height and width. The conductors are given equal but opposite uniform surface charge densities ± σ. Ignore edge effects and use Gauss’s law to show (a) that for points far from the edges, the electric field between the plates is $E=\sigma /{\in }_0$ and (b) that outside the plates on either side the field is zero. (c) How would your results be altered if the two plates were nonconductors? (See Fig. 22–30).