The magnetic moment and moment of inertia of a magnetic needle as shown are, respectively, 1.0 × 10^-2 A m^2 and (10^-6)/(π^2) kg m^2. If it…

The magnetic moment and moment of inertia of a magnetic needle as shown are, respectively, $\displaystyle 1.0 \times 10^{-2} \mathrm{~A} \mathrm{~m}{ }^2$ and $\displaystyle \frac{10^{-6}}{\pi^2} \mathrm{~kg} \mathrm{~m}^2$. If it completes $\displaystyle 10$ oscillations in $\displaystyle 10$ s, the magnitude of the magnetic field is: