Pearson Edexcel International GCSE (9–1) · PHYSICS · Chapter
Electromagnetism
68 practice questions
Topics covered
Practice questions
11–20 of 33 · Easy
Question 11
1 mark · Easy
Answer and see the solution →Name one way to increase the current produced by electromagnetic induction in a generator.
Question 12
2 marks · Easy
Answer and see the solution →(a)[1 mark]A student moves a straight wire downwards between the poles of a magnet. What is observed in the wire?
(b)[1 mark]Explain why this happens.
Question 13
1 mark · Easy
Answer and see the solution →What is the primary purpose of a generator?
Question 14
2 marks · Easy
Answer and see the solution →(a)[1 mark]A dynamo is attached to a bicycle wheel. Describe briefly what happens to the magnetic field inside the dynamo as the bicycle wheel turns.
(b)[1 mark]Explain how the turning magnet inside the dynamo leads to a current in the coil.
Question 15
2 marks · Easy
Answer and see the solution →Explain why no voltage is produced in a wire if it is held still in a magnetic field and why a voltage is produced when the wire is moved.
Question 16
1 mark · Easy
Answer and see the solution →Give one practical application of electromagnetic induction.
Question 17
1 mark · Easy
Answer and check →What must be true for a transformer to work properly?
- A.The current in the primary coil must be alternating (a.c.).
- B.The secondary coil must be thicker than the primary coil.
- C.The voltage in the secondary coil must be higher than the primary coil.
- D.Both coils must be made of iron.
Question 18
2 marks · Easy
Answer and see the solution →A transformer has 200 turns on its primary coil and 400 turns on its secondary coil. The input voltage is 10 V a.c.
Calculate the output voltage from the secondary coil.
Question 19
3 marks · Easy
Answer and see the solution →The diagram below shows a basic transformer.
A simple transformer with labelled input and output (a)[1 mark]State the name of the part labelled as 'soft iron core'.
(b)[2 marks]Explain why a soft iron core is used in a transformer.
Question 20
3 marks · Easy
Answer and see the solution →A transformer is used to reduce the voltage from a mains a.c. supply of 120 V to 12 V for use in a toy train set. The primary coil has 480 turns.
(a)[1 mark]Is this a step-up or a step-down transformer? Explain your answer.
(b)[2 marks]Calculate the number of turns that should be on the secondary coil.