- ● Magnet - Substance that attracts iron
- The materials which are attracted by a magnet are called magnetic materials. Examples: iron, steel, cobalt.
- ● Types-
- Natural -The first natural magnet was discovered in Magnesia, a town in Greece. It was called the lodestone.
- Artificial magnets -are made of iron or steel. They are bar magnet, cylinderical magnet, U-shaped magnet, horseshoe magnet, magnetic needle, and compass.
- ● Properties:
- A magnet attracts small pieces of iron.
- A magnet always rests in the north-south direction, if it is free to swing.
- Like poles repel each other and unlike poles attract each other.
- Poles always exist in pairs, cannot be isolated.
- ● USES-
- Magnets are used to separate iron and steel from their mixture with non-magnetic substances. –
- Magnets are used in many electrical appliances such as an electric bell, loud-speaker, etc.
- A magnetic compass is used by sailors and navigators to find the north-south direction.
- ● Methods to make magnet
- 1.Magnetic induction-Magnetic induction is the process in which a piece of iron temporarily behaves like a magnet in the presence of another magnet
- 2.Single touch method
- 3.Double touch method
- 4.Electrical method- Electromagnet
- ● Demagnatisation-
- A magnet can be destroyed
- by rough handling,
- by dropping it several times,
- by hammering it repeatedly
- by heating it.
- ●Storage- Magnetic keepers are used to store the magnets.
- Magnetic keepers are small pieces of soft iron.
