Pearson Edexcel International GCSE (9–1) · PHYSICS · Section
ELECTRIC MOTORS AND ELECTROMAGNETIC INDUCTION
16 practice questions
Practice questions
11–16 of 16
Question 11
2 marks · Normal
Answer and see the solution →Explain why a wire carrying a current experiences a force when placed at right angles to a uniform magnetic field.
Question 12
1 mark · Normal
Answer and see the solution →State the device which uses the motor effect to produce sound waves.
Question 13
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 14
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 15
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 16
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.