Applications of electromagnetism
A circuit breaker is designed to cut off an electricity supply if the current becomes too high.
When current flows through the circuit the coil of wire becomes an electromagnet.
The trip switch is made of a magnetic material and so is slightly attracted to the electromagnet. Normally, the magnetic force is not strong enough to move the switch.
If something goes wrong and the current becomes too large, the switch is strongly attracted to the magnet.
This breaks the circuit and prevents any further current from flowing.
When the switch is manually reset, current may flow through the circuit again.