1. Natural magnet:

   Those magnets which are found in nature is called natural magnet. They are found irregular in shape and it has the weaker force of attraction. Lodestone and magnetite are some examples of the natural magnet.
   
   

2. Artificial magnet:

   Artificial magnets are those magnets that are made by humans by using various methods. They are of various shapes and sizes and has the strong force of attraction. Artificial magnets are generally made from special iron or steel alloys which are usually magnetised electrically. They may be bar-shaped, horseshoe-shaped magnetic needles, magnetic compass, etc. There are two types of artificial magnets which are as follows,

   

   
   
   Temporary magnet: Temporary magnets are the magnets that can retain their magnetic properties for the short period of time. They are made of soft magnetic materials like soft iron, steel, etc. They are magnetised by passing an electric current through an insulated wire, It creates the strong magnetic field due to which they are magnetised. They lose their magnetism when the electric current is stopped or external magnetic field disappears. An electromagnet is one of the examples of a temporary magnet. They are used in an electric bell, electric motor, electric fan, etc.
   
   Permanent magnet: These magnets retain their magnetic properties for the long period of time. They are made of hard magnetic substances like steel, cobalt, iron, etc. They are made of hard ferromagnetic material. They are used in speaker, transistor, radio, tape recorder, etc.

Activity 1
Bring some pieces of iron and a bar magnet. Then keep the pieces of iron near the bar magnet. What do you observe? What do you conclude from this activity?

Activity 2
Bring a bar magnet and suspend it freely with the help of nylon thread and stand. Then, rotate the magnet and observe the direction of the bar magnet after it comes at rest. Does the magnet show north- south direction after coming at rest? What do you conclude from this experiment?

Methods of Making Magnets

There are various methods of making magnets. Magnets of desired shapes and sizes can be made artificially by using magnetic substances. Some common methods of making magnets are as follows,

Rubbing method
The artificial magnet can be prepared by rubbing strong bar magnet over the surface of magnetic substances for several times. It can be done by two methods,

1. Single touch method: In single touch method, a single magnet is rubbed over the surface of the magnetic substance in only one direction by using the same pole for several times. Magnetic substances like a blade, iron bar, iron clips, etc. can be magnetised.
2. Double touch method: In double touch method, two magnets are used for rubbing. Here, unlike poles of two magnets are rubbed at the centre of magnetic substances for more than half an hour.

Electrical method:
Electrical method is used for making temporary magnets like an electromagnet. Here, the magnetic substances are magnetised by passing electricity. It consists of a coil made of insulated copper wire that is wound around the magnetic substance. The two ends of the wire are connected with the battery having a switch. When the switch is made on, the current flows through the coil and the magnetic substance becomes a magnet. When the switch is made off, the magnetic substance loses the magnetic properties. The magnets which are made by passing electricity are called electromagnet.

Precaution while making electromagnet

• Instead of using naked wire, insulated copper wire should be used to prevent from short circuit.
• The winding should be done only from one side.
• The strength of the electromagnet can be increased by increasing number of turns of coil, amount of electric current and by using a soft magnetic substance.

Activity 3
Bring a bar magnet, pieces of iron and a steel bar. Then rub the surface of the steel bar by using the same pole of the bar magnet. Repeat this action for several times for more than half an hour. Then keep the pieces of iron near the steel bar. What do you observe? What do you conclude from this activity?

Activity 4
Bring a long insulated wire, pieces of irons, soft magnetic substance (bar), battery and a switch. Then wind the wire over the bar for several times, join both ends of the wire with the battery and switch. Now keep some pieces of iron near the nails and turn the switch on. What happens to the pieces of iron when you turn switch on and off ? What do you conclude from this experiment?

Uses of Magnets

1. They are used in electric motors and generators.
2. They are used in electric bells.
3. They are used in refrigerators to keep the door closed.
4. They are used in TV screens, computer screens, telephones and in tape recorders.
5. They are used in the magnetic compass.
6. Magnets are also used in medicines like in MRI.
7. They are used to lift the heavy loads.