A spherical conducting shell of inner radius ' r₁ ' and outer radius ' r₂ ' has a charge ' Q '. A charge -q is placed at the center of the shell. The surface charge density on the inner and outer surface of the shell will be

Step-by-step solution

Due to charge -q at the center of the shell, a charge q will be induced on the inner surface and -q on the outer surface. The charge on outer surface will become Q-q . Hence surface charge densities will be q 4 r ₁^2 and Q - q 4 r ₂^2