A flywheel turns the coil of a generator. A student spins the flywheel and then stops applying a force to it.
The student carries out two trials from the same initial rotation frequency.
The results are shown in the table.
| Trial | Initial rotation frequency in Hz | Rotation frequency after 4.0 s in Hz |
|---|---|---|
| A | 20.0 | 18.4 |
| B | 20.0 | 11.2 |
Calculate how many times greater the mean rate of decrease in rotation frequency is in Trial B than in Trial A.
Explain why the flywheel slows down more quickly in Trial B.
The student replaces the 12 Ω resistor with a 6.0 Ω resistor.
Predict how this affects the initial rate of decrease in rotation frequency. Explain your answer.
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.