Not a hw question: A spherical conducting shell of inner radius a and outer radius b carries a total charge of +Q distributed on the surface of a conducting shell. http://ocw.mit.edu/OcwWeb/Physics/8-02Electricity-and-MagnetismSpring2002/VideoAndCaptions/detail/embed03.htm [Broken] If you watch prof. Lewin, he says that a uniformly distributed charge on a shell has an electric field outside the shell, but not inside. Can someone explain why so? I thought if we had a surface such as a plate, the E-field points out in both directions, but why doesn't it exist in a sphere? sorry for no pics.