A rectangular coil 0.12 m long and 0.10 m wide has 50 turns and carries current 2 A in a uniform magnetic field 0.2 T. Its plane makes an angle 30° with the field direction. Find the torque required to keep it in equilibrium.
Options

Question

A rectangular coil 0.12 m long and 0.10 m wide has 50 turns and carries current 2 A in a uniform magnetic field 0.2 T. Its plane makes an angle 30° with the field direction. Find the torque required to keep it in equilibrium.

Options

G1 Physics · Accepted Answer

Step 1: Rectangular coil area is A=(0.12m)(0.10m)=0.012m², with 50 turns and I=2A. Step 2: Magnetic moment μ=NIA=50×2×0.012=1.2 A·m². Step 3: Torque τ=μBsinθ; when the coil plane makes 30° to B its normal makes 60°, giving τ=1.2×0.2×sin60°≈0.208N·m≈0.20N·m. Answer B. Final answer: (B) 0.20 N·m.