Using electromagets
I can describe how electromagnets are used in cranes, locks, bells and motors.
Using electromagets
I can describe how electromagnets are used in cranes, locks, bells and motors.
Lesson details
Key learning points
- An electromagnetic door lock uses an electromagnet to pull a magnetic bolt to unlock a door.
- An electric bell often contains an electromagnet that attracts and moves the striker, making it hit the bell.
- As an electromagnet moves the striker in an electric bell, it breaks its own circuit to let the striker spring back.
- A motor contains a spinning coil of wire that is an electromagnet.
- When there is a current in the spinning coil of wire in a motor, other magnets around it will push it round.
Common misconception
It is very common for pupils to think that uninsulated wire is needed for the coil of an electromagnet.
When discussing an electromagnet, always refer to the insulated wire in its core, which is necessary so the current in each turn adds to the strength of the electromagnet.
Keywords
Electromagnet - A magnet made by running current through a coil of wire round an iron core.
Temporary magnet - An electromagnet that loses its magnetism when current stops flowing through it.
Electric lock - A lock that can be opened with an electromagnet when a switch is closed.
Electric bell - A bell that uses an electromagnet to strike a clapper on the bell and which resets itself to keep ringing.
Electric motor - A motor that uses a magnetic field to produce a force.
Equipment
Insulated wire, AAA battery, 2 safety pins, insulating tape, neodymium magnet and sandpaper.
Content guidance
- Risk assessment required - equipment
Supervision
Adult supervision required
Licence
This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
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