GCSE Level Questions: Transformers


(a) The basic structure of a transformer is a primary coil of insulated wire, an iron core and a secondary coil of insulated wire.

(i) Why is the core made of iron?

(Max 1 mark)

(ii) Explain how a transformer works.

(4 marks)

(b) A small step-down transformer is used in the charger for an electric screwdriver. The input to the transformer is 230 V a.c. mains supply and the output is 5.75 V a.c. There are 3200 turns on the primary coil.

Calculate the number of turns on the transformer's secondary coil.

Show clearly how you work out your answer

(2 marks)

(Total 7 marks)