1. Magnetism

2. A bar magnet has two ends labelled ‘N’ for north and an ‘S’ for south
A bar magnet has two ends labelled ‘N’ for north and an ‘S’ for south. The N means that end of the magnet is attracted to and so it points towards north pole and the south is seeking the south pole.
Each magnet has an invisible magnetic field around it. When Iron filings are sprinkled above a magnet, the filings are drawn to the most powerful parts of the magnet, which are located at the ends. The ends are called the poles.

3. When there are two bar magnets placed beside each other, the iron filings show us the invisible lines of magnetism and how they change.
When the N and the S are close to each other, the iron filings show the strong lines of magnetism between them. When two like poles (N N or S S are placed beside each other, the iron filings show that there isn’t any attraction between the them.
When we look at these experiments, we learn a few basic rules.
Magnetism is strongest at the poles
Opposite poles attract
Like poles repel