An engineer tests three electromagnets for an electromagnetic brake. Each coil is wound around an identical iron core. The engineer measures the minimum current needed for each electromagnet to pull the same iron plate across the same gap.
| Electromagnet | Number of turns | Minimum current in A |
|---|---|---|
| P | 150 | 2.4 |
| Q | 300 | 1.2 |
| R | 600 | 0.60 |
Describe what the results show about the effect of the number of turns on the minimum current.
90 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.