GCSE Standard Questions: Transformers

Q5. (a) Ragnar used a simple transformer to investigate how the number of turns on the secondary coil affects the potential difference (p.d.) across the secondary coil.

Ragnar kept the p.d. across the primary coil fixed at 2V.

The graph shows Ragnar's results.

(i) The graph contains one anomalous result. Suggest one possible reason why this anomalous result occurred.

[1 mark]

(ii) The transformer changes from being a step-down to a step-up transformer. How can you tell from the graph that this happens?

[1 mark]

(b) A spot-welder is a device that uses a transformer to produce a large current to join sheets of metal together. The diagam below shows a transformer demonstrating how a large current can heat and join two nails together.

(i) How does the amount of infrared radiation emitted by the nails change when the power supply is switched on?

[1 mark]

(ii) Calculate the current from the power supply needed to provide a power output of 336 W. Use the data in the diagram and assume the transformer is 100% efficient.

[5 marks]


(Total 8 marks)