Magnetic moment of a rotating ring| Rod and spherical shell

In side a hollow spherical shell

Volume of Spherical Shell

In side a hollow isolated spherical shell-

The moment of interia of a spherical shell about a tangent is 20 kg m^(2) . What is the minimum moment of intertia about any axis ?

A charge Q is spread uniformly over an insulated ring of radius R .What is the magnetic moment of the ring if it is rotated with an angluar velocity omega about its axis?

A ring of dielectric material, with a total charge +q distributed uniformly over its surface, rotates with angular speed omega. Find the magnetic moment of the ring .Compare its magnetic moment with its angular momentum , assuming that its mass is m.

A magnet of magnetic moment M is rotated through 360^(@) in a magnetic field H, the work done will be

Surface area of Spherical Shell

A : Gravitational potential is constant everywhere inside a spherical shell . R : Gravitational field inside a spherical shell is zero everywhere .