A rectangular current loop in the z=0 plane has corners (0,0,0), (1,0,0), (1,2,0), (0,2,0), carries 5 A anticlockwise, and is in uniform B⃗=(2î+2ĵ-4k̂) T. Which option gives the total force and torque?

Question

G1 Physics · Accepted Answer

In a uniform field, net force on any closed loop is zero. Magnetic moment is μ⃗=IA k̂=5×(1×2)k̂=10k̂ A·m². Torque τ⃗=μ⃗×B⃗=10k̂×(2î+2ĵ-4k̂)=20î-20ĵ N·m, magnitude 20√2 N·m. Hence A.