GCSE Standard Questions: The Generator
Q4. The diagram shows a student's design for a simple wind speed gauge.
![](diagram4.png)
(a) Explain why the wind causes the a.c. voltmeter to give a reading. The explanation has been started for you.
The wind causes the plastic cups to turn. This causes the spindle and magnet to turn. The (magnetic) field / lines of force / flux rotate(s) / move(s) / through / in / cut(s) the coil
A potential difference / p.d. / voltage is then induced across the coil ![](../../../../graphics/symbols/nuclides/ticksmall.png)
(2 marks)
(b) The gauge is not sensitive enough to measure light winds. Suggest one way that the design can be modified to make the gauge more sensitive.
any one from:
- more powerful / stronger / lighter magnet
![](../../../../graphics/symbols/nuclides/ticksmall.png)
- larger / more / bigger / lighter cups / with a bigger aperture area
![](../../../../graphics/symbols/nuclides/ticksmall.png)
- longer arms
![](../../../../graphics/symbols/nuclides/ticksmall.png)
- lubricate the spindle
![](../../../../graphics/symbols/nuclides/ticksmall.png)
- add more turns to the coil / nail
![](../../../../graphics/symbols/nuclides/ticksmall.png)
(1 mark)
(Total 3 marks)