Question

What is the direction of magnetic field lines outside the bar magnet?

Answer 1

1. Definition: The orientation of magnetic field lines outside a bar magnet seems to be northern to southern pole. Inside the magnetic substance, the magnetic field seems to be the strongest force.
2. Near the poles, the strongest external magnetic fields exist. A magnetic northern pole would attract another magnet's southern pole while repelling a northern pole.

Therefore, the north to the south pole is the direction of magnetic field lines outside a bar magnet.