Question

What is magnetism in brief?
What are its advantages

Answer 1

Magnetism

Magnetism is the property of a material to exert an attractive force or repulsive force on another material.

Magnets

Materials having property of magnetism are called magnets. Magnets attract materials like iron, mineral lodestone, nickel, some steel and cobalt. Such materials are called magnetic substances. These substances help in the detection of the existence of magnetic force.

The property of magnetism can be temporary or permanent. It makes the magnets either temporary or permanent. Temporary magnets retain magnetic properties for shorter periods while permanent magnets retain magnetism for a loner period.

Magnetic Field

Magnetic field is a region outside the magnet where its magnetic forces can be experienced. It is represented be magnetic field lines. Following diagram shows the magnetic field lines of bar magnet-

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Advantages of Magnetism

• Magnets are used in electric motors which in turn is used to run refrigerators, vacuum cleaners, washing machines, compact disc players, electric fans, etc. at home.
• Magnets are also used in audiotape and videotape players to record and read information.
• Magnets are used in speakers to transform signals into sounds.
• Magnets are also used in devices like cranes, cutters, fax machines, computers, etc.
• Electromagnets are used in transformers to convert high-voltage electricity into low-voltage electricity.
• Magnets are also used in trains, subways, trolleys, monorails, escalators, elevators, etc.
• In medicine, magnets are used for diagnostic purposes.
• The magnetic field of Earth protects it from charged winds of high temperature coming from sun.

Answer 2

Magnetism

• It is a concept that helps us understand the fundamental interactions in nature, the interaction between moving charges.

• Magnetism’s presence is felt when there are moving charges as a result of electricity.

• Magnetism is the force exerted by magnets when they attract or repel each other.

Magnetic Field

Magnetic Field is the region around a magnetic material or a moving electric charge within which the force of magnetism acts.

Magnetic Field Lines

• Magnetic field lines are a visual tool used to represent magnetic fields.
• They describe the direction of the magnetic force on a north monopole at any given position.

Magnets

• An object which is capable of producing magnetic field and attracting unlike poles and repelling like poles.

• When a magnet is dipped in iron filings, we can observe that the iron filings cling to the end of the magnet as the attraction is maximum at the ends of the magnet. These ends are known as poles of the magnets.

• Magnetic poles always exist in pairs.

• Like poles repel each other while unlike poles attract each other.

• The magnetic force between the two magnets is greater when the distance between these magnets are lesser.

Advantages of Magnetism

1. Magnets are used in speakers, electric bells, TV and computer screens, telephones, refrigerators, smartphones, clocks, compasses, etc.
2. Magnetism is used in treatment of eye diseases like cataract, by using a small electromagnet.
3. Magnets are used in medicinal purposes.
4. It is used in electric meters such as galvanometers, voltmeters, rheostats, ammeters, speedometers etc.
5. Magnets are used for lifting huge masses, for transportation, etc.
6. Magnetism is used in electrical appliances like fans, some switches, in our vehicles, etc.
7. Magnets are used in computer appliances like Compact Disks, DVDs, LED screens, pen drives, etc.
8. Magnets are used in credit cards too.
9. These are used in electromagnets.
10. These are used in producing electric current (this can be observed in a galvanometer).