Two large conducting plates are placed parallel to each other and they carry equal and opposite charges with surface density `sigma` as shown in figure (30-E6). Find the electric field (a) at the left of the plates, (b) in between the plates and © at the right of the plates.

Explanation

Given : `surface density = sigma`
(a) and © for any point to the left and right
of the dual plater, the electric field is zero
As there are no electric flux outside the
system.
(b) For a test charge put in the middle
Total electric field
` (sigma/2 epsilon_0) + (sigma/2 epsilon_0) = (sigma/ epsilon_0)` .