A current loop placed in a uniform magnetic field:

Question

G1 Physics · Accepted Answer

Step 1: A current loop in a uniform magnetic field has magnetic dipole moment μ⃗ normal to its plane and potential energy U=−μBcosθ. Step 2: The torque is τ=μBsinθ, so equilibrium is possible when θ=0° or θ=180°. Step 3: At θ=0°, U=−μB is minimum ⇒ stable; at θ=180°, U=+μB is maximum ⇒ unstable. Step 4: Hence the loop has TWO equilibrium orientations, one stable and one unstable: D. Final answer: (D) Can be in equilibrium in two orientations, one stable and the other unstable..