In a uniform magnetic field, the magnetic needle has a magnetic moment 9.85 × 10^-2 A / m^2 and moment of inertia 5 × 10^-6 kg m^2. If it performs 10…

In a uniform magnetic field, the magnetic needle has a magnetic moment $\displaystyle 9.85 \times 10^{-2} \mathrm{~A} / \mathrm{m}^2$ and moment of inertia $\displaystyle 5 \times 10^{-6} \mathrm{~kg} \mathrm{~m}^2$. If it performs $\displaystyle 10$ complete oscillations in $\displaystyle 5$ seconds then the magnitude of the magnetic field is \_\_\_\_ mT. [Take $\displaystyle \pi^2$ as $\displaystyle 9.85$]