Practice question

Given: The magnetic potential energy of a dipole with m = 0.8 A m² in a field B = 0.25 T at 180° is: These values define the system as per NCERT data. Formula: U_m = -m B cosθ. This is standard NCERT relation. Substitution & Calculation: Given: m = 0.8 A m², B = 0.25 T, θ = 180°, cos 180° = -1 . Substitute: U_m = -0.8 × 0.25 × (-1) = 0.2 J . Result: The computed value matches expected outcome and confirms correct choice as per NCERT.