Pearson Edexcel International GCSE (9–1) · PHYSICS · Unit
Magnetism and Electromagnetism
293 practice questions
Topics covered
Practice questions
121–130 of 139 · Easy
Question 121
2 marks · Easy
Answer and see the solution →Explain briefly why a transformer is needed to distribute electricity over long distances.
Question 122
3 marks · Easy
Answer and see the solution →A transformer used for a phone charger has 500 turns on its primary coil and 100 turns on its secondary coil. The input voltage is 230 V.
(a)[1 mark]Is this transformer step-up or step-down? State why.
(b)[2 marks]Calculate the output voltage.
Question 123
1 mark · Easy
Answer and see the solution →Name the two main types of transformers used in the transmission of electricity.
Question 124
1 mark · Easy
Answer and see the solution →State the purpose of a step-down transformer in the National Grid.
Question 125
2 marks · Easy
Answer and see the solution →Explain why it is important to use high voltages when transmitting electricity over long distances in the National Grid.
Question 126
1 mark · Easy
Answer and see the solution →What does a step-up transformer do to the voltage of electricity?
Question 127
1 mark · Easy
Answer and check →Which device is used to increase the voltage in the National Grid?
- A.A fuse
- B.A step-down transformer
- C.A generator
- D.A step-up transformer
Question 128
3 marks · Easy
Answer and see the solution →A simplified diagram of the National Grid is shown below. Complete the sentences about the use of transformers.
(a)[1 mark]Describe where in the National Grid a step-up transformer is used.
(b)[1 mark]Describe where in the National Grid a step-down transformer is used.
(c)[1 mark]Explain why step-down transformers are needed before the electricity is supplied to homes.
Question 129
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 130
2 marks · Easy
Answer and see the solution →Describe what would happen if the National Grid did not use transformers.