Magnet : Magnet is a material to which objects made of iron, nickel and cobalt get attracted.

Discovery of a magnet : The shepherd named Magnes from Greece discovered the magnet. Once while he was sitting on a rock, he found that his shoes and staff remained attached to this rock. It was with great force that he had to remove it. This rock was named as magnetite. Magnetite is a natural magnet.

Magnetism : The property of a magnet to attract certain materials is called magnetism.

• All the substances do not stick to the magnets. Some get attracted and remain firmly attached to it. Some do not. Usually those which stick to the magnet are metallic materials.
• Sand, pieces of paper, sawdust do not stick to the magnet. Iron filings and pins get attached to the magnet. They come out of the mixture in the saucer.

Magnetic materials : The materials that stick to a magnet are called magnetic materials

Non-magnetic materials : The materials that do not stick to a magnet are called non-magnetic materials.

Mariner’s compass : Mariner’s compass was invented from a rock called loadstone (leading stone). Loadstone is a rock piece from magnetite. If loadstone is hung freely, it settles in north-south direction. Therefore in olden days, people from China and Europe started using loadstone for finding out directions. Through this practice, Mariner's compass was invented.

Man-made magnets : Depending on the type of use, various magnets are now made by man. They are man-made magnets. e.g. Bar magnets, disc magnets, horse-shoe magnets, ring-shaped magnets, cylindrical magnets, etc.

Magnetism : The object is displaced when attracted by a magnet. This happens due to the magnetic force. Magnetic force thus brings the displacement and performs work.

• Magnetic force is used in various places such as factories, ports, garbage depots, in cranes to pick up large and heavy loads. This magnetic force is therefore a kind of energy.

Attraction and repulsion : There is repulsion (going away) in the like (i.e. similar) poles of a magnet while there is attraction (coming closer) in the opposite (i.e. dissimilar) poles of a magnet.

Temporary magnetism : The magnetism which lasts for a short while and is temporary is called temporary magnetism.

• Activity : Take a needle or a nail. Place it steady on a table. Keep on rubbing a magnet over it from one end to the other. Do this 7-8 times. In the above activity, needle or nail acquires temporary magnetism.

Electromagnet : If an electric current is passed through an object, there is temporary magnetism produced in it. When the current is put off, the magnetism vanishes. Such a temporary magnet formed due to electric current is called an electromagnet. Magnetism produced in such electromagnets is called electromagnetism.

• Electromagnetism is used in various daily activities. e.g, electric doorbell, crane, etc.

Permanent magnets : The magnets in which there is permanent magnetism are called permanent magnets. Such magnets are made from a mixture of nickel, cobalt and iron. Magnetic material called Alnico is a mixture of Aluminium, Nickel and Cobalt.

Destruction of magnetism : When a magnet is heated, thrown or knocked about or broken into pieces, its magnetism is lost. Therefore, it has to be kept well maintained and stored.

Magnet keeper: For the protection of a magnet, a bar of soft or pure iron is kept along with a magnet in the box. This bar protects the magnet and is therefore called a magnet keeper.