Show that the normal component of electrostatic field has a discontinuity from one side of a charged surface to another given by
`(oversetrarr(E_2)-oversetrarr(E_1))overset^n=sigma//epsilon_0` where `overset^n` isa unit vecotr normal to the surface at a point and ct is the surface charge density at that point. (The direction of `overset^n` is from side 1 to side 2.) Hence, show that just outside a conductor, the electric field is `sigmaoverset^n//epsilon_0`.