Practice question

**Magnetic field lines** form continuous closed loops, direction given by tangent at point, density indicates field strength. Unlike electric field lines, magnetic lines never intersect because unique field direction exists at each point, and bar magnet possesses dipole moment m = N I A directed from south to north pole inside magnet. Gauss’s law for magnetism states that the net magnetic flux through any closed surface is zero, as magnetic field lines form closed loops with no monopoles. Substituting values gives Zero, which matches expected magnitude for this magnetic configuration, confirming dipole field dependence on m/r³ and torque relation τ = m B sinθ.