In a uniform magnetic field of 0.049 T, a magnetic needle performs 20 complete oscillations in 5 seconds as shown. The moment of inertia of the…

In a uniform magnetic field of $\displaystyle 0.049$ T, a magnetic needle performs $\displaystyle 20$ complete oscillations in $\displaystyle 5$ seconds as shown. The moment of inertia of the needle is $\displaystyle 9.8 \times 10^{-6} \mathrm{~kg} \mathrm{~m}^2$. If the magnitude of magnetic moment of the needle is $\displaystyle x \times 10^{-5} \mathrm{Am}^2$; then the value of ' $\displaystyle x$ ' is :