A magnetized needle is placed $30^{\circ}$ with direction of uniform magnetic field of intensity $3 \times 10^{-2}\;T$ The torque acting on the needle is $7.2 \times 10^{-4} \;J$ Calculate the magnetic moment of the needle .

Question

$\begin{array}{1 1} 4.8 \times 10^{2}JT^{-1} \\ 4.8 \times 10^{-7}JT \\ 4.8 \times 10^{-2}JT \\ 4.8 \times 10^{-2}JT^{-1}\end{array}$