# Bar magnets

Most materials are not , but some are. A magnetic material can be magnetised or will be attracted to a magnet. These metals are magnetic:

• iron
• cobalt
• nickel

Steel is mostly iron, so steel is magnetic too.

A bar magnet is a . This means that its magnetism is there all the time and cannot be turned on or off. A bar magnet has two magnetic poles:

• (or north-seeking pole)
• (or south-seeking pole)
The north pole is normally shown as N and the south pole as S

## Attract and repel

If you bring two bar magnets together, there are two things that can happen, and :

• if you bring a north pole and a south pole together, they attract and the magnets stick together
• if you bring two north poles together, or two south poles together, they repel and the magnets push each other away

We say that opposite poles attract, and like poles repel.

## Testing for magnets

How can you test if a piece of metal is actually a magnet? Seeing if it sticks to a magnet is not a good test, because unmagnetised iron, steel, cobalt and nickel objects will also do this. So you can only show that an object is a magnet if it repels a known magnet.