A closely wound solenoid of $2000$ turns and area of cross section $1.6 \times 10^{-4}m^2$, carrying a current of $4.0\;A$ is suspended through its center allowing it to turn in a horizontal plane. What is the magnetic moment associated with the solenoid ?

Question

$\begin{array}{1 1} 128\;J/T \\ 12.8\;J/T \\ 1.28\;J/T \\ 0.128\;J/T \end{array}$