Poles that attract and repel, permanent and induced magnets, field lines, and how a plotting compass shows the Earth's field.
What you will learn
- Predict whether two poles attract or repel
- Tell a permanent magnet from an induced one
- Draw and read field lines, and plot them with a compass
Poles push and pull
Every magnet has a north pole and a south pole, where its magnetic effect is strongest.
- Like poles (N and N, or S and S) repel.
- Unlike poles (N and S) attract.
These are non-contact forces: the magnets do not have to touch.
Only a few materials are attracted to a magnet: iron, steel, nickel and cobalt. Copper, aluminium, brass and plastics are not.
The rest of this lesson and its 9 practice questions are locked.
In this lesson
- Poles push and pull
- Permanent and induced magnets
- Field lines
- The plotting compass and the Earth
- Try it: Attract or repel?
9 practice questions, marked as you go; about 20 minutes in all.
Key terms
North pole, South pole, Repel, Attract, Permanent magnet, Induced magnet, Magnetic field, From N to S, Close together
In this unit: Magnetism and electromagnetism
Magnets and field lines, electromagnets, the motor effect and F = BIl, then loudspeakers, generators, microphones and transformers.