7. Two positive charges Q positioned at (0,d/2) in vacuum experience a repelling force of 4περα2 when they are at rest,...
A charge q is positioned at point (0,0,d) above a grounded conducting plate (V=0 on the plate). Use the method of images (see lecture notes) to find the electric field on the plate. Since the electric field inside the conductor is zero (charges are not moving), use Gauss’s Law to find the surface charge density σ(r) on the plate and show that the total charge on the plate is –q.