Question

The north pole of a magnet always points towards the when suspended freely
(A) South
(B) North
(C) West
(D) East

Answer 1

Hint Magnetic field lines always travel from north to South Pole. When a magnet is suspended freely it stays in the earth’s north-south direction. In other words, it aligns along the magnetic meridian. So the north pole of the magnet points along the north direction while South Pole points along the south direction.

Complete step-by-step solution
We all know that everything in this universe tends to go towards a lower energy state. Whenever a magnet is suspended freely, it means that it can rotate in the plane below it. Its magnetic field lines will always run from its north pole to its south pole, just like any other magnet. Similarly, earth’s magnetic field lines also run from north to south-pole. When the north of suspended magnet points towards the south of Earth, its magnetic field lines repel from the earth’s magnetic field lines. This will cause a higher or unstable energy state and the magnet will try to find an orientation where it can achieve a lower energy state. So, it will point towards the north, placing its magnetic field lines in the direction of earth’s magnetic field.

Therefore, the correct answer is option B.

Note: This same condition of a suspended magnet is the principal of a magnetic compass.
When a bar magnet is left free in a uniform magnetic field, it aligns itself in the directional field. In that case:
Work: $W = MB(1 - \cos \theta )$
Potential energy: $U = - MB\cos \theta $