Explain the underlying principle of working of a parallel plate capacitor .
If two similar plates , each of area A , having surface charge densities `+sigma` and `-sigma` are separated by a distance 'd' in air , write expression for :
the potential difference between the plates.

Explanation

For underlying principle of working of a parallel plate capacitor .
If two similar plates , each of area A , have surface charge densities `+sigma` and `-sigma` and are separated by a distance d in air , then
potential difference between the plates `V_(1) - V_(2) = Ed = (sigma)/(in_(0)) d`