I have a question about the surface charge and the potential. My physics book states that the potential inside the conductor is the same at the surface. But the potential is just the electric field times the radial distance. Does this mean that it is possible to determine the electric field at a point EXACTLY on the surface of a conductor. I was not sure that was possible or not. If it is possible, would it simply be 1/4pi e R^2, which means that at exactly the surface of a conductor, the electric field is like a point charge at the center of the conducting sphere, R units away.