We use magnetism in so many ways that modern life would be impossible without it.
We need magnetism to produce large amounts of electricity in power stations.
There are magnets in compasses, loudspeakers, electric motors, refrigerator doors, computer disks, and many other useful appliances.
Magnetism is an invisible force that can make some things move towards each other, or move away from each other, or stay in one place.
We can’t actually see magnetism, but we can look at magnets and see what happens to certain things that are put near them.
The area around a magnet is called a magnetic field.
When magnets and some metals are inside a magnetic field, magnetism makes them move.
A strong enough magnet can make steel paper clips jump off a table. This is caused by an invisible force, called magnetism, which surrounds every kind of magnet.
What are magnets made of?
Permanent magnets are made of metal and can make other metals move toward them.
Scientists describe metals that magnets can attract in this way as magnetic.
But not all metals are magnetic.
For example, magnets do not attract aluminum or copper.
You can find out for yourself whether something is magnetic or nonmagnetic.
Hold a small magnet near a piece of paper to see if the paper will move towards the magnet. Now try the same experiment with things made of plastic, glass and cloth.
Are these materials magnetic or nonmagnetic?
Iron filings stick to the ends of a magnet where the magnetic force is strongest.
These ends are called the poles of the magnet.
What shape is a magnet?
Magnetism works in a different way around each shape of magnet.
We use bar magnets in compasses, horseshoe magnets in small electric motors, and disk magnets in radio, television, or stereo.
Magnetic Poles – North and south poles
Scientists call one end of a bar magnet the north-seeking pole because it always tries to point towards the north.
The other end is called the south-seeking pole.
We call them the north pole and south pole for short.
Do you want to know which end of your bar magnet is the north pole?
You can find out which direction is north with a compass.
Hang the magnet from a piece of string so that it can swing freely. When it eventually stops swinging, the end of the magnet that points north is the north pole of the magnet.
Like and unlike poles
You can feel two magnets attract each other if you hold the north pole of one magnet near the south pole of another magnet. But if you put two poles of the same kind close together, two north poles or two south poles, then the magnets will repel each other. Scientists have a rule to help us remember this. The rule is, “Like poles repel, unlike poles attract.”
You can’t make the magnets stay together if you put two like poles next to each other.
The north pole of one magnet, for example, will always repel the north pole of another magnet.
If you want your magnets to attract each other and stay close together, the north pole of one magnet must be next to the south pole of the other magnet.