List the properties of magnetic field lines.

Explanation

Magnetic field lines have the following properties :
i] They originate from the north pole and enter into the south pole of the magnet.
ii] They are closed and continuous curve.
iii] They never intersect each other.
iv] They are closer where the magnetic field is stronger [poles of the magnet] and far apart where the field is weaker.
v] They have the same strength.
vi] They contract lengthwise and expand sidewise. This leads to attraction between unlike poles and repulsion between like poles.