Inside a bar magnet, the magnetic field lines

The correct answer is Option (3) → go from the south pole to the north pole

The magnetic field lines of a bar magnet form closed loops. Outside the magnet, they leave the north pole and enter the south pole.

Option (1) do not exist — Incorrect. A magnetic field line does not stop at a pole. Each line goes on through the body of the magnet to close its loop, so there is a field inside the magnet too.

Option (2) go from the north pole to the south pole — Incorrect. This is the direction outside the magnet. If the lines ran from north to south inside as well, they could not join up into closed loops.

Option (3) go from the south pole to the north pole — Correct. A line that enters the magnet at the south pole runs through it back to the north pole. Only then is the loop complete.

Option (4) depend on the material of the magnet — Incorrect. Every magnet has closed field lines. The material decides how strong the magnet is, not the direction of its field lines inside.

NCERT (2026-27):
The magnetic field lines – “(i) The magnetic field lines of a magnet (or a solenoid) form continuous closed loops. …”