A charge q is uniformly distributed on a non conducting disc of radius R. It is rotated with an angular speed 'w' about an axis passing through the centre of mass of the disc and perpendicular to its plane. The magnetic moment of the disc is
A charge q is uniformly distributed on a non conducting disc of radius R. It is rotated with an angular speed 'w' about an axis passing through the centre of mass of the disc and perpendicular to its plane. The magnetic moment of the disc is