GCSE Standard Questions: The Generator

(Electromagnetic Induction)

Q6. The diagram shows a simple seismometer made by a student.

To test that the seismometer works, the student pushes the bar magnet into the coil and then releases the bar magnet.

(a) Why does the movement of the bar magnet induce a potential difference across the coil?

[2 marks]

(b) Why is the induced potential difference across the coil alternating?

[1 mark]

(c) The sketch graph shows how the potential difference induced across the coil varies after the bar magnet has been released.

Which statement in the table below describes the movement of the magnet when the induced potential difference is zero? Tick one box.

Statement Tick here
Accelerating upwards.  
Constant speed upwards.  
Decelerating downwards.  


[1 mark]

(d) The seismometer cannot detect small vibrations.

Suggest two changes to the design of the seismometer that would make it more sensitive to small vibrations.

[2 marks]

(Total 6 marks)