Magnetite is the very common magnet found in nature. A magnet attracts small pieces of iron towrds itsef. When a magnet is suspended freely, it always points in the north-south direction.
The substances which are strongly attracted by a magnet or can be converted into a magnet artifically are called magnetic substances. Iron cobal and nickel are example of magnetic substances
Substances which are neither attracted by a magnet nor can be convertd into artificial magnets are called non-magnetic substances.
Poles of a Magnet
The ends of a magnet where most of its magnetic strength is acting are called magnetic poles. A magnet have two poles
- North Poles: The end of the freely suspended magnet, which points towards the geographic north is called north pole of the magnet
- South Poles: The end of the freely suspended magnet, which points towards the geographic south is called south pole of the magnet
Types of magnet
Magnet is generally are of two types:
- Temprory Magnet: The magnets which cannot retain their magnetism for a long time are called temprory magnets for eg: if soft iron is magnetised by rubbing with a steel magnet, it loses its magnetism, as soon as the subbing is stopped, Smilarly electromagnets lose their magitism as soon as the current stops flowing through them.
- Permanent Magnet: The magnets which retains thei magnetism for a very long time are called parmanent magnets.
A magnetic compass is a simple device used by the pilots and navigators to find the diredtion in which their ship or aeroplane is going.
Magnetism in Earth
The earth acts as a huge bar magnet. The geographic north pole of earth lies in the magnetic sout pole of earth. Thus when a bar magnet is suspended freely, the south magnetic pole of the earth attracts the north pole of the magnet and vice-versa.