Question 16 of 57

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