A charge Q is placed at the center of a conducting spherical shell of inner radius R1 and outer radius R2. The sphere has no net charge.
Ok, I have some statements for this setup. Would you be kind to check them?
The Attempt at a Solution
1) The electric field in a distance R < R1 from the pointcharge Q is the electric field coming from the charge itself.
2) The electric field in a distance R1 < R < R2 is zero (E-field zero inside a conductor always).
3) In a distance R > R2 the electric field is only coming from the point charge, since the conductor has no net charge.
4) The formula for the electric field outside a conductor: E = (sigma/epsilon_0)n. Does this only apply to the outside surface of a conductor, or also the inside surface? (In this case the inside-surface of the spherical shell)