Pearson Edexcel International GCSE (9–1) · PHYSICS · Unit
Magnetism and Electromagnetism
293 practice questions
Topics covered
Practice questions
81–90 of 139 · Easy
Question 81
3 marks · Easy
Answer and see the solution →A student wishes to investigate how the force on a wire in a magnetic field changes when they change the current and the strength of the field.
(a)[2 marks]State two variables the student can change to increase the force acting on the wire.
(b)[1 mark]State one way the student could decrease the force on the wire.
Question 82
3 marks · Easy
Answer and see the solution →A loudspeaker converts electrical energy into sound using the motor effect.
(a)[1 mark]Name the part of the loudspeaker that moves to create sound waves.
(b)[1 mark]State what causes this part to move.
(c)[1 mark]Briefly explain why the motion of this part can change direction.
Question 83
1 mark · Easy
Answer and check →Which one of the following changes would NOT increase the turning force produced by a simple electric motor?
- A.Increase the number of turns of wire in the coil.
- B.Increase the strength of the magnetic field.
- C.Increase the current in the coil.
- D.Use a steel core instead of a soft iron core.
Question 84
1 mark · Easy
Answer and see the solution →State what is meant by electromagnetic induction.
Question 85
1 mark · Easy
Answer and check →Which of these actions will increase the size of the voltage induced in a coil of wire?
- A.Moving the magnet more quickly into the coil
- B.Using a weaker magnet
- C.Reducing the number of turns in the coil
- D.Keeping the magnet stationary inside the coil
Question 86
1 mark · Easy
Answer and see the solution →Name one way to increase the current produced by electromagnetic induction in a generator.
Question 87
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 88
1 mark · Easy
Answer and see the solution →What is the primary purpose of a generator?
Question 89
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 90
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.