A magnetic field is represented by a series of lines around a magnet.
The path along which north pole moves in a magnetic field is called magnetic lines of force or magnetic field line.
Magnetic field lines are a visual tool used to represent magnetic fields. They describe the direction of the magnetic force on a north monopole at any given position.
*They seek the path of least resistance between opposite magnetic poles.
*They never cross one another.
*They all have the same strength.
*Their density decreases (they spread out) when they move from an area of higher permeability to an area of lower permeability.
*Their density decreases with increasing distance from the poles.
*They are considered to have direction as if flowing, though no actual movement occurs.
*They flow from the south pole to the north pole within a material and north pole to south pole in air.