Question

In which direction does a freely suspended compass needle align itself?

Answer 1

The earth acts as a magnetic bar and a magnetic bar has both positive terminals and negative terminals. Also, it is assumed that the field lines of the magnet originate from the positive terminal (north-pole) and go to the negative terminal (south-pole). The magnetic field lines cannot overlap each other.

Complete answer:
The core of the earth has its magnetization property that generates its magnetic field that sustains the main part of the field which we measure on the surface of the earth. Our Earth itself behaves like a bar magnet.All magnets have two poles namely; a north pole and a south pole. We can note that the north pole of one magnet is always attracted towards the south pole of another magnet and vice-versa.

Also, the compass needle itself is a little magnet possessing two magnetic poles. So the earth acts as a very big magnet due to the magnetic field created by its core. The Earth's magnetic South Pole lies near to its geographic north and hence the compass needle when allowed to spin whichever way it wants, will always line itself along the north-south direction.

When a magnetic needle is freely suspended over the earth, we are able to say that the south pole of the magnetic needle is attracted towards the north pole of the earth and the north pole of the magnet is always attracted towards the south pole of the magnet.

Note: Also, the intensity of the magnetic field can be determined by the space between the two successive field lines. We are able to conclude that the denser the field line higher is the magnetic field intensity. As we move away from the poles magnetic field intensity decreases.