JEE Main 2019 Physics question
A rectangular coil (Dimension 5 cm × 2.5 cm) with 100 turns, carrying a current of 3 A in the clock-wise direction, is kept centered at the origin and in the X-Z plane. A magnetic field of 1 T is applied along X-axis. If the coil is tilted through 45º about Z-axis, then the torque on the coil is:
Answer: (D)
Solution
τ = NIAB sin 45° = 100 × 3 × 12.5 × 10 × 1 × 0.707 ≈ 0.27 N m.