Magnet

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Bar magnet

A magnet is a very special metal. When a magnet goes near a special kind of metal or other magnets, and the poles (sides) touching are opposite, it will pull, or attract the other metal or magnet closer. Also, if the two poles are the same, the two magnets will push away, or repel, from each other. This is called magnetism. Magnets can make some other metals into magnets when they are rubbed together. A "soft" or "impermanent" magnet is one which loses its memory of previous magnetizations. "Soft" magnetic materials are often used in electromagnets to enhance (often hundreds or thousands of times) the magnetic field of a wire that carries an electrical current and is wrapped around the magnet; the field of the "soft" magnet increases with the current. Permanent magnets occur naturally in some rocks, particularly lodestone, but are now more commonly manufactured. A magnet's magnetism decreases when it is heated and increases when it is cooled. It has to be heated at around 1000 degrees Celsius. Natural/permanent magnets are not artificial and is made from a kind of rock called lodestone or magnetite. Like poles (S-pole and S-pole/N-pole and N-pole) will repel each other while unlike poles (N-pole and S-pole) will attract each other.

Magnets are only attracted to special metals. Metals that have iron and steel attract magnets well. Metals like brass, copper, zinc and aluminum are not attracted to magnets. Also, non-magnetic materials such as wood and glass are not attracted to magnets as they do not have the right particles inside them like magnetic materials do.

A compass uses the Earth's magnetic field, and will always point to the North Pole. A north side of the magnet is attracted to the south side of another magnet. However, the north side of the compass points to the north pole, this can only mean that the "north pole" is really the magnetic south, and the "South Pole" is really the magnetic north.

History[change | edit source]

The first people to discover the magnetic rocks were the Chinese. They called it "the loving stone" because the stones love metal the way parents love children. At first the Chinese used the stones to perform fortune-telling and magic tricks. Later on they used the 'loving stones' to invent the compass.[1]

References[change | edit source]

  1. Cole, Joanne; Bruce Degen (2001). Magic School Bus, Amazing Magnetism. United States of America: Scholastic Inc.. pp. 11. ISBN 0-439-31432-1.

Other pages[change | edit source]