Electromagnetism
Science: KS3, topic 3.4.14
Electromagnets
Electromagnets are temporary magnets. Unlike permanent magnets, electromagnets can be switched on and off.
Current and magnetic fields
- When current flows through a wire, a magnetic field is produced around it.
- The closer to the wire, the stronger the electromagnetic force.
Current stops
- If the current stops, the magnetic field will stop.
- The electromagnet will turn off.
Electromagnets
- A coil of wire that generates a magnetic field is a solenoid.
- You can make electromagnets stronger by:
- Wrapping the wire around an iron core.
- Increasing the number of turns the coil has.
Test yourself on Electromagnetism
What is a solenoid?
Select the true statement in each pair
An electromagnet is holding a metal object. What happens to the object when the current is switched off?