Practice question

Given: The magnetic potential energy of a dipole with m = 0.3 A m² in a field B = 0.6 T at 45° is: These values define the system as per NCERT data. Formula: U_m = -m B cosθ. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: Given: m = 0.3 A m², B = 0.6 T, θ = 45°, cos 45° = frac1sqrt2 approx 0.707 . Substitute: U_m = -0.3 × 0.6 × 0.707 approx -0.12726 J approx -0.13 J . Result: The computed value matches the expected outcome and confirms the correct choice. Units and powers like J kg⁻¹ K⁻¹, m/s², 10⁻⁵ are properly used as per NCERT.