Pearson Edexcel International GCSE (9–1) · PHYSICS · Unit
Magnetism and Electromagnetism
293 practice questions
Topics covered
Practice questions
181–190 of 293
Question 181
3 marks · Normal
Answer and see the solution →When a magnet is pushed into a coil of wire, a voltage is produced across the ends of the coil. The voltage disappears if the magnet stops moving.
(a)[2 marks]Explain why a voltage is only induced when the magnet is moving.
(b)[1 mark]Give one way to increase the maximum voltage produced in this experiment.
Question 182
4 marks · Normal
Answer and see the solution →A portable generator is used at a roadworks site to provide electrical power. The generator has a coil rotating inside a strong magnetic field.
Describe how electricity is produced in this generator and state two factors that will increase the amount of electricity generated.
(a)[2 marks]Describe what happens as the generator coil turns inside the magnetic field.
(b)[2 marks]State two ways the amount of electricity generated can be increased.
Question 183
3 marks · Normal
Answer and see the solution →You are given a coil of wire, a bar magnet, and a sensitive voltmeter.
Describe a practical experiment to show electromagnetic induction and how you would demonstrate that the induced voltage depends on the speed of movement.
(a)[1 mark]Describe how you would set up the apparatus to show an induced voltage.
(b)[2 marks]Describe what you would do to investigate how the induced voltage changes with speed.
Question 184
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 185
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 186
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 187
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.
Question 188
2 marks · Easy
Answer and see the solution →State and explain why transformers only work with alternating current (a.c.) and not with direct current (d.c.).
Question 189
3 marks · Easy
Answer and see the solution →A transformer has 120 turns on its primary coil and 480 turns on its secondary coil. The input voltage is 6 V a.c.
(a)[1 mark]Is this transformer a step-up or a step-down transformer? Explain your answer.
(b)[2 marks]Calculate the output voltage from the secondary coil.
Question 190
3 marks · Easy
Answer and see the solution →Look at the diagram of a transformer below and answer the questions.
Diagram of a transformer (a)[2 marks]Name the part labelled 'core' in the diagram and state its purpose in the transformer.
(b)[1 mark]Is this transformer a step-up or a step-down transformer? Explain your answer.