Magnet is a substance that attracts the iron pieces is called  a magnet and the magnetism is the property of magnet by which attraction takes place.

The ancient People was first introduce The invisible force of the magnet. but they consider it to be purely magical quantity. As the study of magnet is developed then the magnetism attained a place of pride in the Electrical Engineering field. In 1819 Oersted was Discovered a relation between electric current and magnetism. Today Magnetism is so deep rooted that without its aid it is impossible to operate such device as Electric generator , motor, transformer , electrical instruments , Television , radio and many other devices.

There are two type of Magnet.

Natural Magnet:  The Iron ore ( Magnetite Fe3O4 ) Pieces Which possess the property  of attraction small iron pieces are called natural magnet.

Artificial Magnet: The pieces of some magnetic material which attain magnetic Property by artificially are called artificial magnet. The artificial magnet may be two types. 

a. Temporary Magnet A substance which retain  magnetism as long as the  magnet force is applied are called the Temporary magnet. When magnetic force is removed. they lose almost all their has wide application in the field of electrical equipment, generator , motor electric bells and relays etc. this magnet generally prepare by metal soft iron and nickel.
b. Permanent Magnet A substance which retain  magnetism is permanently is called permanent magnet. Even if force of magnetism is remove.They are used in many application like electrical instrument, earphone loudspeaker and motors. this magnet generally prepare by metal hardened steel and certain magnetic alloy such as cobalt steel , tungsten steel.

Classification of magnetic materials

Ferromagnetic Materials: The Material which has tremendous magnetic properties are called ferromagnetic materials. Some materials iron , nickel and cobalt  which are attracts the magnet. These materials generally use for making permanent magnet and temporary magnets. Some alloy like tungsten-steel , nickel-cobalt, cobalt-steel and ceramic like ferrite are also used as magnetic materials

Non-Magnetic Materials: The materials which do not exhibit magnetic property are called non-magnetic like rubber, wood, plastic etc.

Paramagnetic Materials: The Material which has very slight magnetic  properties and weakly attract by magnetic materials  are called paramagnetic materials. these materials are aluminum platinum etc. but in practically these materials are consider as non magnetic materials.

Diamagnetic Materials: The Material which show a very slight opposition to the magnetic line force and repelled by magnet are called Diamagnetic Materials. these materials are copper and silver etc. but in practically these materials are consider as non magnetic materials.

Magnetic Polarity
If A piece of magnet dipped into iron fillings, it will observed that large quantity of iron filings cluster sticking to the end of bar the magnet. these ends has a maximum magnet effect and for convenience are called poles of magnet.  A piece of magnet has two poles , north pole and south pole. to determine the polarity of magnet poles, For which  the piece of magnet is suspended or pivoted at its center and hang in air. The magnet is rests in a definite position. One end points in the direction of earth' north pole called north pole and other end point in the direction of  of earth' south pole called south pole.
It is observed that if the bar magnet is broken into two pieces ,each piece will be a complete magnet with two poles at its ends. No matter how many times a magnet is broken, every time each piece will have two poles , North pole and south pole.the poles of magnet can not be separated and each poles have equal strength.


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