Rajkumar said to you that the magnetic field lines are open and they start at north pole of bar magnet and end at south pole. What questions do you ask Rajkumar to correct him by saying "Field lines are closed"?

Explanation

1) IF the magnetic field lines,start at north pole and end at south pole , where do the lines go from south pole.
2) What is happening within the bar magnet
3) Are the magnetic field lines passing through bar magnet
4) What is the direction of magnetic field lines inside the bar magnet? (Recall the solenoid activity).
5) Can you say now, that the magnetic field lines are open.