Q find e and v at 0,0,- q(0,0,d) o (oro p(0,0,-d/2) -q(0,0,-d) this gives e 0 but actually as we know potential and field below the plane is zero. thus this exp

Q Find E and V at 0,0,- q(0,0,d) O (OrO p(0,0,-d/2) -q(0,0,-d) This gives E 0 but actually as we know potential and field below the plane is zero. Thus this expression only valid at z 0