A hollow, conducting sphere with an outer radius of 0.240 m and an inner radius of 0.200 m has a uniform surface charge density of +6.47 × 10⁻⁶ C/m². A charge of -0.900 μC is now introduced into the cavity inside the sphere.
A. What is the new charge density σ on the outside of the sphere? Express your answer with the appropriate units.
B. Calculate the strength of the electric field E just outside the sphere. Express your answer with the appropriate units.
C. What is the electric flux through a spherical surface just inside the inner surface of the sphere? Express your answer with the appropriate units.