Asolid, nonconducting sphere of radius r = 4.0 cm is charged uniformly with an electric charge q = 10 mc. it is enclosed by a thin, concentric, spherical conducting shell of inner radius r. as shown in the figure. the net charge on the shell is zero. find the magnitude of the electric field inside the sphere (r lesserthan r) at a distance r = 2.0 cm from its center. find the magnitude of the electric field outside the shell (r greaterthan r) at a distance r = 5.0 cm from the center of the sphere. what is the surface charge density (charge per unit area) sigma induced on the inner surface of the shell?