A magnetic needle of a magnetic moment $60 Am^2$ is placed at a place . The needle points towards the geographical north. using the data given below, find the value of declination at the point . Horizontal component of earth magnetic field $=40 \times 10^{-6}wb m^{-2}$ and torque experienced by the needle $=1.2 \times 10^{-3}Nm$

Question

$\begin{array}{1 1} 30^{\circ} \\ 60^{\circ} \\ 90^{\circ} \\ 0^{\circ} \end{array}$