Pearson Edexcel International GCSE (9–1) · PHYSICS · Chapter
Electromagnetic Induction
61 practice questions
Topics covered
Practice questions
21–24 of 24 · Easy
Question 21
2 marks · Easy
Answer and see the solution →Give one reason why transformers are essential in the National Grid. Then, name one device in your home that works at the voltage supplied after a step-down transformer.
(a)[1 mark]State one reason why transformers are used in the National Grid.
(b)[1 mark]Name one device in your home that operates at mains voltage (230 V).
Question 22
2 marks · Easy
Answer and see the solution →Describe what would happen if the National Grid did not use transformers.
Question 23
1 mark · Easy
Answer and see the solution →What is the approximate voltage supplied to homes after passing through a step-down transformer in the UK?
Question 24
4 marks · Easy
Answer and see the solution →Electricity generated at a power station is transmitted long distances before entering homes.
(a)[2 marks]Explain why a step-up transformer is used before electricity is transmitted through the National Grid.
(b)[2 marks]A step-up transformer increases the voltage from 10,000 V to 100,000 V. If the current in the primary coil is 50 A, and the transformer is 100% efficient, calculate the current in the secondary coil.