A spherical shell of radius R carries a uniform surface charge density (charge per unit area) . The center of the sphere is at the origin and the shell rotates with angular velocity (in rad/sec) around the z-axis ( at the origin). Seen from below, the sphere rotates clockwise.

Calculate the magnitude of the total current (in A) carried by the rotating sphere
Calculate the magnitude of the magnetic field Bz (in T) that is generated by the circular current of the rotating shell at a point P on the -axis for

Question

A spherical shell of radius   R carries a uniform surface charge density (charge per unit area)  . The center of the sphere is at the origin and the shell rotates with angular velocity   (in rad/sec) around the  z-axis (  at the origin). Seen from below, the sphere rotates clockwise.

Calculate the magnitude of the total current (in A) carried by the rotating sphere 
Calculate the magnitude of the magnetic field  Bz (in T) that is generated by the circular current of the rotating shell at a point P on the  -axis for