In an electric bell, the hammer strikes the gong over and over while the switch is held closed. Which explains why the striking is repeated?
The electromagnet reverses its poles each time the hammer strikes the gong
The electromagnet is switched off by the gong each time the hammer hits it
The moving arm breaks the circuit, so the electromagnet lets it spring back
The moving arm warms the circuit, so the electromagnet loses its magnetism
39 exam-style questions on AQA GCSE Physics 7.2 The motor effect, covering 7.2.1 Electromagnetism, 7.2.2 Fleming's left-hand rule (HT only), 7.2.3 Electric motors (HT only), and 7.2.4 Loudspeakers (HT only). Each one has a worked solution and a mark scheme showing where the marks go.