Magnetism

Magnets are generally of two types: natural magnets and artificial magnets. Natural magnets are naturally occurring magnets. Loadstone is an example of a natural magnet. Artificial magnets are the man-made magnets. Horseshoe shaped magnet and Bar magnet are the example of artificial magnets.

Properties of magnets

• A magnet has the ability to attract magnetic properties.
• A freely suspended magnet points North-South direction.
• Like poles repel and unlike poles attract.
• The magnetic poles cannot be separated by breaking the magnet.

Molecular theory of magnetism

Molecular theory of magnetism states, "If molecular magnets align in a row, then the substance exhibits magnetic property. If they are kept haphazardly, they do not exhibit magnetic property." This is the molecular theory of magnetism.

If molecular magnets align in a row, then the substance exhibits magnetic property. If they are kept haphazardly, they do not exhibit magnetic property. This is the molecular theory of magnetism. The poles of a magnet cannot be separated even by breaking into pieces because they exist in a pair and every molecule of a magnet has poles in the pair.

Evidence of molecular theory of magnetism

1. The poles of a magnet cannot be separated.
2. A magnet has more force at its ends than in the middle.
   Reason: The molecular magnets are arranged in an open chain so that the north pole or the south pole of molecular magnets lie in the same direction which gives strong force at the poles whereas two opposite poles are arranged at the middle and the force cancel each other. So, poles have more force than the middle portion.
3. Only magnetic bodies can be magnetised.
4. A magnet gets demagnetized by
   • Dropping regularly from a certain height
   • Hammering a magnet
   • By heating a magnet
   • Rubbing the same pole, etc