A hollow sphere has charge `'q'` which is uniformly distributed over its surface and rotating about its axis .Find the magnetic moment of the sphere

Options

A. `(qr^(2)omega)/(2)`
B. `(qr^(2)omega)/(3)`
C. `qr^(2)omega`
D. `(qr^(2)omega)/(4)`

Answer

2

Explanation

Select an annular ring of radius `r sin theta` and thickness `rd theta. d mu` is its magnetic moment.
`d mu=((rsing theta)^(2)omegadq)/(2),dq=(q)/(4pir^(2))(2pir^(2)sin thetad theta)`
`mu=underset(0)overset(pi)int d mu`