1Two poles
Every magnet has a north pole and a south pole. Its pull is strongest at the poles, which is why paperclips cling to the ends and not the middle.
north polesouth pole
Lesson 27.1 notes
Magnets and poles
North and south poles, attraction and repulsion, and magnetic materials.
2Attract and repel
Two north poles push apart: like poles repel. So do two south poles. A north pole and a south pole pull together: unlike poles attract.
repelattract
3A force across a gap
Magnets push and pull without touching: magnetic forces are non-contact forces. The closer the magnets, the stronger the force; it gets weaker very quickly with distance.
non-contact force
4Magnetic materials
Only a few metals are magnetic: iron, nickel, cobalt and most steel (steel is mostly iron). Copper, aluminium, gold, plastic, glass and wood aren't attracted.
magnetic
5Making magnets
Near a magnet, iron and steel become magnets themselves, so paperclips cling in a chain. Iron loses this when the magnet goes; steel can become a permanent magnet.
permanent magnet
6Is it a magnet?
To test a metal bar, bring each end near one pole of a magnet. Plain iron is attracted every time. If one end is pushed away, the bar is a magnet.
7Cut it in half
Cut a magnet in half and you get two smaller magnets, each with its own north and south pole. You can never get a north pole on its own.
Explore: Magnet lab
Drag one magnet towards the other and flip it round to see them attract or repel. Then test which things a magnet picks up.
Common mistake: Only repulsion proves it's a magnet
Both poles of a magnet attract an iron nail, so attraction only shows that a thing is magnetic. Only repulsion proves that it is a magnet itself.
Remember
- Every magnet has a north pole and a south pole. Like poles repel; unlike poles attract.
- Magnetic forces are non-contact forces: they act across a gap and get weaker quickly with distance.
- Iron, steel, nickel and cobalt are magnetic. Near a magnet, a piece of iron becomes a magnet itself.
Going further at GCSE