Three Properties of Magnets

Attracting Magnetic Substances

• A magnet has the ability to attract magnetic substances, such as steel and iron. The maximum attracting ability of a magnet is concentrated at its two ends, which are known as poles of a magnet. This property of a magnet is best displayed by dropping a magnet into a bowl full of iron filings. You will notice the filings attaching themselves all over the magnet. But, you will also notice that the maximum iron filings are attached to the two ends of the magnet. When magnets attract magnetic substances, they can even induce magnetism in them. This magnetism is temporary though.

Freely Suspended Magnet Assumes North-South Direction

• If a magnet is suspended from a thread, it will assume a north-south direction. This direction is same as the geographic direction. The pole pointing towards the north is referred to as the north pole, whereas the pole pointing south is known as the south pole. Even if the magnet is turned to some other direction and then released, it will go back to the north-south direction.

Like Poles Repel; Unlike Poles Attract

• Like poles of two magnets repel each other, while unlike poles attract one another. Suspend a magnet from a thread; and then bring one end of another magnet close to the north pole of the suspended magnet. If the pole of the other magnet is its south pole, the suspended magnet will move closer to it. On the other hand, if the other magnet's pole is also its north pole, the suspended magnet will move away.

Use of Magnets in Modern Life

• The properties of a magnet, or magnetism, have made their way into modern life without people realizing it. The ability of a computer's hard drive to write and store information depends on internal disks known as platters, which are made out of magnetic material. In the field of medicine, medical imaging has been revolutionized by magnetism. Magnetic resonance imaging allows doctors to see detailed images of the different structures and tissues in the body. There are even magnetic trains that run on magnetic tracks. The repelling property of like poles is used to levitate the train, so that high speeds can be achieved without any friction. These trains are currently used in Shanghai, China; and Japan.