JEE MAIN - Physics (2021 - 27th July Morning Shift - No. 25)
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]
پاسخ دهید
8
توضیح
$$T = 2\pi \sqrt {{I \over {MB}}} $$
B = 80 $$\times$$ 10$$-$$4 = 8 mT
B = 80 $$\times$$ 10$$-$$4 = 8 mT