Question

No two magnetic lines of force will cut each other?

Answer 1

A magnetic field line is that path in space that points in the direction of the magnetic field at every point along it. Walk along a magnetic field line carrying a compass and the needle will always point in the direction you need to go in order to stay on that magnetic field line. If two field lines crossed then that is saying that the magnetic field points in two different directions at one place. There's only one direction to the magnetic field at any place at any time so this doesn't happen.