A hollow, conducting sphere with an outer radius of 0.243 m and an inner radius of 0.203 m has a uniform surface charge density of +6.45*10^(-6) C/m^2. A charge of - 0.840 microC is now introduced into the cavity inside the sphere.
(a) What is the new charge density on the outside of the sphere?
(b) Calculate the strength of the electric field just outside the sphere.
(c) What is the electric flux through a spherical surface just inside the inner surface of the sphere?