Pearson Edexcel International GCSE (9–1) · PHYSICS · Unit
Magnetism and Electromagnetism
293 practice questions
Topics covered
Practice questions
81–90 of 154 · Normal
Question 81
1 mark · Normal
Answer and see the solution →State the device which uses the motor effect to produce sound waves.
Question 82
3 marks · Normal
Answer and see the solution →A coil is used to make an electromagnet by wrapping it around a nail and connecting it to a battery.
(a)[1 mark]Describe how the magnetic field produced by the coil is different from the field produced by a straight wire.
(b)[2 marks]State two ways in which the strength of this electromagnet can be increased.
Question 83
4 marks · Normal
Answer and see the solution →A wire is placed horizontally between the poles of a magnet so that it is perpendicular to the magnetic field. The current in the wire is 2.5 A and the magnetic field strength is increased.
(a)[2 marks]State what will happen to the force on the wire as the magnetic field strength increases. Explain your answer.
(b)[1 mark]Describe one change you could make to the wire itself to increase the force further.
(c)[1 mark]How would the direction of the force change if the direction of current in the wire is reversed?
Question 84
3 marks · Normal
Answer and see the solution →You are asked to demonstrate the motor effect using a simple setup in the laboratory.
(a)[1 mark]List the main components you would need to carry out this demonstration.
(b)[1 mark]Describe briefly what you would observe when the experiment is performed correctly.
(c)[1 mark]State how you could reverse the direction of movement of the wire.
Question 85
3 marks · Normal
Answer and see the solution →The diagram shows a rectangular coil inside a simple electric motor. The coil rotates between the poles of a magnet.
Simple electric motor setup: coil, split ring, magnets. (a)[1 mark]State the purpose of the split ring in this motor.
(b)[2 marks]Give two ways to increase the speed at which the motor turns.
Question 86
4 marks · Normal
Answer and see the solution →A straight wire is moved quickly at right angles through the magnetic field between the poles of two magnets, as shown below.
A wire AB moving at right angles across a uniform magnetic field between north and south poles. (a)[1 mark]State the name of the process by which a voltage is produced in the wire.
(b)[2 marks]Explain how the movement of the wire causes a voltage to be induced in it.
(c)[1 mark]Give one way, other than moving the wire faster, to increase the size of the induced voltage.
Question 87
3 marks · Normal
Answer and see the solution →Generators are used in power stations to produce electricity for homes and businesses.
Explain, in terms of electromagnetic induction, how a generator can produce electricity. Include what needs to move and why this movement is necessary.
Question 88
1 mark · Normal
Answer and check →Which of the following will NOT increase the size of the voltage induced in a wire by electromagnetic induction?
- A.Using a stronger magnet
- B.Moving the wire faster across the magnetic field
- C.Increasing the number of turns in the coil
- D.Using a weaker magnet
Question 89
3 marks · Normal
Answer and see the solution →A student investigates how the induced voltage in a coil changes with the speed of a moving magnet. Her results are shown in the table.
Induced voltage vs. speed of magnet Speed of magnet (cm/s) Induced voltage (V) 2 0.6 4 1.2 6 1.8 8 2.4 (a)[1 mark]Describe the relationship between speed and induced voltage shown by the data.
(b)[2 marks]Predict the induced voltage if the speed of the magnet is increased to 10 cm/s.
Question 90
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.