The magnetic lines of force due to a bar magnet

Magnetic field lines are continuous closed loops that represent the direction and strength of a magnetic field [1][t2]. A fundamental property of these lines is that they never intersect or cross each other [1][t5][t6]. This is because the magnetic field at any specific point in space must have a unique, single direction [t5]. If two lines were to intersect, it would imply that a compass needle placed at the point of intersection would point in two different directions simultaneously, which is physically impossible [1]. Outside a bar magnet, these lines emerge from the north pole and enter the south pole, while inside the magnet, they travel from the south pole to the north pole to complete the loop [1][t4]. Even at neutral points, where the magnet's field is cancelled by an external field like Earth's, the lines do not intersect; rather, the net field intensity becomes zero [t7].

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 12: Magnetic Effects of Electric Current > Activity 12.3 > p. 197