In the figure shown a coil of single turn is wound on a sphere of radius r and mass m. The plane of the coil
is parallel to the inclined plane and lies in the equatorial plane of the sphere. If sphere is in rotational equilibrium the value of B is (current in the coil is i)

(A) $\frac{mg}{\pi ir}$                (B) $\frac{mg \sin \theta }{\pi i}$              (C) $\frac{mgr \sin \theta }{\pi i}$            (D) None of these
mg sin O
(D) None of these
mgr sin O