An engineer tests a sensor that detects when an electromagnet is switched off. The sensor contains a sensing coil close to the electromagnet. The sensing coil is connected to a voltage sensor.
In each test, the magnetic field through the sensing coil falls by the same amount, but takes a different time to fall.
The table shows the results.
| Time taken for the magnetic field to fall in ms\mathrm{ms}ms | Peak induced potential difference in V\mathrm{V}V |
|---|---|
| 12.0 | 0.30 |
| 6.0 | 0.60 |
In another test, the magnetic field falls by the same amount in 4.0 ms.
Predict the peak induced potential difference. Explain how you used the results and why reducing the time affects the peak induced potential difference.
92 exam-style questions on Edexcel GCSE Physics 13.1 Inducing a current, covering 13.1.1 Producing an electric current by induction, 13.1.2 Factors affecting the induced potential difference, 13.1.3 Alternators and dynamos, and 13.1.4 Microphones and loudspeakers. Each one has a worked solution and a mark scheme showing where the marks go.