How does a magnet work?

When you bring a magnet close to another metal object such as a nail, the nail will be attracted towards it. This power of attraction is created by lines of force whi ch surround the magnet. They cannot be seen, but if you place a thin sheet of paper over a magnet, and scatter iron filing on the upper side of the paper, the filing will fall into place according to the lines of force. They will reveal what is known as a magnetic field.

Most of the filings on the paper will be attracted to the two ends of the magnet. These ends are the magnet’s poles. The earth itself is like a giant magnet, with its opposite ends at the North and South Poles. This is why the metal needle of compass will swing round until it is in line with the earth’s magnetic field and points towards the North Pole.