Practice question

**Bar magnet properties** include dipole moment m = pole strength × separation, unit A·m², field lines emerge from north and enter south outside. Lines never cross, ensuring single valued B at any point, and pattern reflects dipole nature with symmetric loops around magnet. When cut along its length, each part typically has half the original magnetic moment in standard problems. Given: m = 1.4 A m² . Each part: m' = (1.4/2) = 0.7 A m² . Substituting values gives 0.7 A m², which matches expected magnitude for this magnetic configuration, confirming dipole field dependence on m/r³ and torque relation τ = m B sinθ.