GCSE Standard Questions: The Generator
Q1. The diagram shows the inside of an oil pipeline and a student's design for a meter to measure the flow of oil.
![](diagram1.png)
- As oil flows through the pipeline, the oil rotates a turbine wheel.
- Above the turbine wheel is a coil of wire connected to a data logger.
- There is a magnet in the rim of the turbine wheel. The turbine wheel spins and this induces a varying potential difference (p.d.) across the ends of the coil.
- This varying p.d. is recorded by the data logger.
(a) Complete the sentence below by suggesting a word for dotted space: The faster the oil flows through the pipeline, the greater
the maximum p.d. across the coil.
(1 mark)
(b) Explain why a varying p.d. is induced across the coil even when the rate of flow of oil remains constant.
The p.d. is produced when the magnetic field/flux lines
cut through the coil.
As the magnet rotates the p.d varies as the distance between magnet and coil changes. ![](../../../../graphics/symbols/nuclides/ticksmall.png)
(3 marks)
(c) Suggest two changes to the design of the meter which would increase the maximum p.d. across the coil for the same flow of oil.
any two from:
- move coil closer to the rim/ wheel
![](../../../../graphics/symbols/nuclides/ticksmall.png)
- use a more powerful magnet • put more turns (on the coil)
![](../../../../graphics/symbols/nuclides/ticksmall.png)
- incorporate a coil with greater area
![](../../../../graphics/symbols/nuclides/ticksmall.png)
- insert an iron core or smaller gap between rim / wheel and coil
![](../../../../graphics/symbols/nuclides/ticksmall.png)
- accept extra magnets
![](../../../../graphics/symbols/nuclides/ticksmall.png)
- do not accept more coils
(2 marks)
(Total 6 marks)