Consider a non conducting plate of radius `a` and mass `m` which has a charge `q` distributed uniformly over it, The plate is rotated about its own axis with a angular speed `omega`. Show that the magnetic moment `M` and the angular momentum `L` of the plate are related as `(M)/(L)=(q)/(2m)`.

Explanation

Since `I = (qv)/(2 pi r)`
So , magnetic
`mu = ia = (qv)/(2 pi r) pi r^(2)`
`rArr mu = (qmur)/(2 m) = (q)/(2m) l`