Magnetism

If you have played with magnets or magnetic toys, you will probably be familiar with two of their basic properties, namely the fact that they attract pieces of iron or steel (Fig. 21.1) and, secondly, if pivoted or sus- Fig. 21.1the nails adhere to the regions at the ends of the magnet known as the poles pended, they always come to rest pointing in a definite direction. When pivoted the end which points towards the North of the Earth is called the North-seeking pole or simply the N-pole. The end which points South is called the South-seeking pole or the S-pole. (Two substances other than iron and steel which are attracted by magnets are cobalt and nickel.)