CHAPTER 4 FUN WITH MAGNETS
DISCOVERY OF MAGNETS
Legend has it that a shepherd named Magnes used to take a stick with him whenever he took his herd of sheep and goats to the nearby mountains for grazing. The stick had a small piece of iron on one end. One day he put his stick on a rock. When it was time to go, he tried to pick up the stick but noticed that it was difficult to pull away he iron from the rock. It was as if the rock was being attracted towards the rock. That is how natural magnets were discovered.
This property due to which a substance attracts iron is called magnetism. Such substances are called magnets.
Natural magnets come from magnetite. Magnetite contains iron and exhibits magnetic properties. Nowadays magnets can be made from pieces of iron. These are called artificial magnets and are made in different shapes like horse shoe magnet, bar magnet, etc.
The materials which get attracted by a magnet are called magnetic materials. E.g.: Iron
The materials which do not get attracted by a magnet are called non-magnetic materials. E.g.: Wood
POLES OF MAGNETS
LIKE POLES AND UNLIKE POLES
It is observed that like poles repel each other. However, unlike poles attract each other.
Note that magnets may lose their properties if they are dropped, heated or hammered. The magnets become weak if they are not stored properly. Therefore, magnets should be stored properly and carefully.