HOW ARE ELECTRICITY AND

MAGNETISM RELATED?

Chapter 15, Lesson 2

What is magnet?

Magnet is an object that attracts iron and a few other metals.

Magnets attract steel because it contains iron.

There are different shapes of magnets:

Some are like bars, some are U-shaped, some are thin and flat.

ARE THESE ITEMS MAGNETIC OR NOT?OUT OF THE FEW ITEMS BELOW, CAN YOU PLACE THE

ITEMS IN THE CORRECT BOX.

NonmagneticMagnetic

If you grouped these objects this way, then you are correct.

Magnetic NonmaneticNonmagnetic

Magnet:

Distance affects the strength of magnet’s attraction.

Magnets differ in size, shape, strength, and uses.

Magnets have two ends or poles, called magnetic poles. One end will point north (N), and the other will point south (S).

Unlike (Opposite) poles of magnets attract each other while like poles of magnets repel.

The space around a magnet in which the force of the magnet acts is called magnetic field.

The force of the magnet is more in the poles than in the middle of the magnet.

Electromagnets:When an electric current passes through a wire, a magnetic field is formed around the wire.

What is an electromagnet?When an electric current is passed through a coil of wire wrapped around a metal core, a very strong magnetic

field is produced. This is called an electromagnet.

We have seen how electricity can produce a magnetic field, but

Can a magnetic field also produce electricity!

Explain how?

Moving a loop of wire through a magnetic field produces an electric current.

A generator is a device used to produce electric.

If you turn a coil of wire in a magnetic field, electricity is produced.

What are electric motors?An electric motor is a device which changes electrical energy into energy of motion “mechanical energy”.

OTHER USES OF MAGNETS:

The edge of the refrigerator door is lined with a magnet. It holds the door to the metal frame.

Floppy disks are made of plastic and coated in magnetic particles. Floppy disks are used to save and retrieve information.

Compasses help people use the earths magnetic force to find their way.

Doorbells use magnets too. The magnet pulls the hammer forward to strike the bell.

Credit cards. The thin, black bar on the back is coated with tiny magnets. It holds information.

There are tiny magnets inside a stereo, telephone, vacuum cleaner and washing machine.