Question

Give short account of the earth’s magnetic field.

Answer 1

When a bar magnet is suspended freely, then it aligns itself along geographical north-south direction i.e. north pole of the magnet points towards the geographical north and south pole of the magnet points towards geographical south direction. William Gilbert suggests that earth itself behaves as a huge magnet. It was assumed that:

1. A huge magnet is burned at the center of the earth.
2. The south end of earth’s magnet is towards the earth’s geographic north and vice-versa.
3. The axis of the earth’s magnet is not in line with the geographical axis but makes a small angle with it.
   The diagram on next page show the earth as a magnet and the magnetic lines of force around it