Pearson Edexcel International GCSE (9–1) · PHYSICS · Section
ELECTRIC MOTORS AND ELECTROMAGNETIC INDUCTION
16 practice questions
Practice questions
1–8 of 8 · Normal
Question 1
1 mark · Normal
Answer and check →Which change will NOT increase the force experienced by a wire carrying a current in a magnetic field?
- A.Increasing the strength of the magnetic field
- B.Increasing the current in the wire
- C.Reversing the direction of the current
- D.Reducing the length of the wire in the field
Question 2
3 marks · Normal
Answer and see the solution →Figure 1 shows a long, straight wire carrying a current. The current flows vertically upwards out of the page.
Figure 1. A long, straight wire with current out of the page. (a)[1 mark]Draw the magnetic field pattern around the wire.
(b)[1 mark]State the rule used to determine the direction of the magnetic field lines.
(c)[1 mark]Explain how the field strength would change if the current is increased.
Question 3
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 4
1 mark · Normal
Answer and see the solution →State the device which uses the motor effect to produce sound waves.
Question 5
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 6
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 7
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 8
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.