A solid conducting sphere of radius a has a net positive charge 2Q . A conducting spherical shell of inner radius b and outer radius c is concentric with the solid sphere and has a net charge -Q . The surface charge density on the inner and outer surfaces of the spherical shell will be

A positive charge Q is placed at the centre O of a thin metalic spherical shell. Select the correct statements from the following: (i) The electric field at any point outside the shell is zero (ii) The electrostatic potential at any point outside the shell is (Q)/(4 pi epsilon_(0) r) , where r is the distance of the point from O (iii) The outer surface of the spherical shell is an equipotential surface (iv) The electric field at any point inside the shell , other than O , is zero

A conducting sphere carries a net charge of -6 mu C . The sphere is located at the center of a conducting spherical shell that carries a net charge of +2 mu C as shown in the figure. Determine the excess charge on the outer surface of the spherical shell.