Question

Are the magnetic field line closed? explain

Answer 1

Hey:
Yes, magnetic field lines are closed curves as they extend from a body of a magnet from north pole to south pole outside the body of the magnet and from south pole to north pole inside the body of the magnet .
Hope this helped you....☺

Answer 2

Yes, magnetic field lines are closed as there pass through the magnet or magnetic substance.
Outside the magnet they move from north to south. But in magnet they move from north to south.

Hope it helps u dear.