In a uniform magnetic field, the magnetic needle has a magnetic moment 9.85 $$\times$$ 10^$$-$$2 A/m² and moment of inertia 5 $$\times$$ 10^$$-$$6 kg m². If it performs 10 complete oscillations in 5 seconds then the magnitude of the magnetic field is _______________ mT. [Take $$\pi$$² as 9.85]