A short bar magnet of magnetic moment 0.4 J·T⁻¹ is placed in a uniform magnetic field 0.16 T. In stable equilibrium the magnetic potential energy is:
Options

Question

A short bar magnet of magnetic moment 0.4 J·T⁻¹ is placed in a uniform magnetic field 0.16 T. In stable equilibrium the magnetic potential energy is:

G1 Physics · Accepted Answer

Step 1: Stable equilibrium means magnetic moment parallel to field, θ = 0°. Step 2: U = −MB cosθ = −(0.4)(0.16)(1) = −0.064 J. Correct option D. Final answer: (D) −0.064 J.