State four properties of magnetic field lines.

The magnetic field lines have the following properties —

1. They are closed and continuous curves.
2. Outside the magnet, they are directed from the north pole towards the south pole of the magnet.
3. The tangent at any point on a field line gives the direction of magnetic field at that point.
4. They are crowded near the poles of the magnet where the magnetic field is strong and far away near the middle of the magnet and far from the magnet where the magnetic field is weak.