Electromagnetic effects — Paper 2 · IGCSE Sciences - Co-ordinated (9-1) 0973

38 Which graph shows how the output voltage of an a.c. generator varies with time? A B voltage voltage 0 0 0 time 0 time C D voltage voltage 0 0 0 time 0 time

1 marks

Answer: A

This question in 0973/21 May/June 2019

39 A current-carrying wire is placed between the poles P and Q of a magnet, as shown. force P Q current The direction of the current is shown. A force acts on the wire in the upward direction as shown. What is the direction of the magnetic field? A from P to Q B from Q to P C towards the bottom of the page D towards the top of the page

1 marks

Answer: B

This question in 0973/22 May/June 2019

40 The output from the generator in a power station is connected to a transformer before electricity is sent along a transmission cable. Why is a transformer used? A to decrease the voltage and decrease the current B to decrease the voltage and increase the current C to increase the voltage and decrease the current D to increase the voltage and increase the current

1 marks

Answer: C

This question in 0973/22 May/June 2019

39 The diagram shows an electrical device. rotation magnet S split-ring commutator N carbon brush battery What is this electrical device? A a d.c. motor B an a.c. generator C a transformer D a solenoid

1 marks

Answer: A

This question in 0973/21 Oct/Nov 2019

38 Which graph shows the voltage output of an alternating current (a.c.) generator? A B + + voltage voltage 0 0 0 time 0 time – – C D + + voltage voltage 0 0 0 time 0 time – –

1 marks

Answer: D

This question in 0973/21 May/June 2020

39 What is the purpose of the slip rings in an alternating current (a.c.) generator? A to allow each end of the coil to contact each carbon brush alternately B to allow each end of the coil to remain in contact with the same carbon brush at all times C to maintain a constant voltage in the output circuit while the coil is rotating D to remain stationary while the coil rotates between them

1 marks

Answer: B

This question in 0973/22 May/June 2020

39 A solenoid carrying a current produces a magnetic field. Which diagram shows the magnetic field pattern? A B current current C D current current

1 marks

Answer: D

This question in 0973/21 Oct/Nov 2020

39 The diagrams each show a wire carrying a current in the direction of the arrow. Which diagram shows the pattern and the direction of the magnetic field around the wire? A B current current C D current current

1 marks

Answer: C

This question in 0973/21 May/June 2021

39 A magnet is moved in and out of a coil and an electromotive force (e.m.f.) is induced. How can the size of the induced e.m.f. be decreased? A Add more turns to the coil. B Move the magnet more quickly. C Move the magnet more slowly. D Turn the magnet around before moving it in and out.

1 marks

Answer: C

This question in 0973/22 May/June 2021

39 The diagram shows a wire carrying an electric current in the direction shown. The wire is at right angles to a magnetic field that is directed into the page. A force acts on the wire because of the current and the magnetic field. In which labelled direction does this force act? wire carrying current A D B C magnetic field into page

1 marks

Answer: B

This question in 0973/21 Oct/Nov 2021

38 A transformer increases the voltage from a power station in order to transfer electricity along transmission cables. How does increasing the voltage affect the current in the cables and how does it affect the efficiency of energy transfer? current efficiency A decreases decreases B decreases increases C increases decreases D increases increases

1 marks

Answer: B

This question in 0973/21 May/June 2022

38 A transformer increases the voltage from a power station in order to transfer electricity along transmission cables. How does increasing the voltage affect the current in the cables and how does it affect the efficiency of energy transfer? current efficiency A decreases decreases B decreases increases C increases decreases D increases increases

1 marks

Answer: B

This question in 0973/22 May/June 2022

39 A current-carrying wire is placed between the poles of a magnet, as shown. The current direction in the wire is shown. A force is produced on the wire. In which labelled direction does the force act? wire B A C S N D current

1 marks

Answer: B

This question in 0973/21 Oct/Nov 2022

37 There is a current-carrying wire perpendicular to the page. The direction of the current is into the page. Which diagram shows the pattern and direction of the magnetic field around the wire? A B current current into page into page C D current current into page into page

1 marks

Answer: A

This question in 0973/22 May/June 2023

38 When a straight conductor moves through a magnetic field, an electromotive force (e.m.f.) is induced between the ends of the conductor. Which factor does not affect the magnitude of the induced e.m.f.? A the length of conductor in the field B the resistance of the conductor C the speed at which the conductor moves D the strength of the magnetic field

1 marks

Answer: B

This question in 0973/22 May/June 2023

39 Cables transmit electrical power. The power input to the cables is constant, but the voltage input is increased. What happens to the power loss from the cables, and what happens to the current in the cables? power loss current in from cables cables A decreases decreases B decreases increases C increases decreases D increases increases

1 marks

Answer: A

This question in 0973/22 May/June 2023

40 The diagram shows a current-carrying conductor in a magnetic field. The direction of the current is shown. current N S In which direction is the force on the wire due to the magnetic field? A downwards B to the left C to the right D upwards

1 marks

Answer: A

This question in 0973/22 May/June 2023

39 A 100% efficient step-down transformer has 120 turns on its primary coil and 10 turns on its secondary coil. A 240 V supply provides 48 W of power to the primary coil. What is the current in the secondary coil? A 0.017 A B 0.2 A C 2.4 A D 20 A

1 marks

Answer: C

This question in 0973/21 May/June 2024

39 What is the purpose of the commutator in a direct current (d.c.) motor? A It reverses the direction of the current in the coil every half turn. B It reverses the direction of rotation of the coil every complete turn. C It reverses the direction of rotation of the coil every half turn. D It reverses the magnetic field due to the permanent magnet every complete turn.

1 marks

Answer: A

This question in 0973/22 May/June 2024

39 A transformer with an efficiency of 100% has an input current of 10 A. The input voltage is 100 V and the output voltage is 20 V. What is the output current? A 2.0 A B 10 A C 50 A D 200 A

1 marks

Answer: C

This question in 0973/21 Oct/Nov 2024

38 The diagram shows the direction of the current in a wire. The wire is placed between the poles of a magnet and this causes a force to act on the wire. In which labelled direction does the force act? B N A C S D current

1 marks

Answer: B

This question in 0973/21 May/June 2025

37 The diagram shows the magnetic field around a straight current-carrying wire. Point X lies in the magnetic field. X current The current is now reduced and its direction is reversed. Which row shows the effect on the strength and direction of the magnetic field at point X? strength of magnetic field direction of magnetic field A decreases reverses B decreases unchanged C increases reverses D increases unchanged

1 marks

Answer: A

This question in 0973/21 Oct/Nov 2025

38 The output from the generator in a power station is connected to a transformer before electricity is sent along a transmission cable. What is a reason for using this transformer? A to decrease the voltage and decrease the current B to decrease the voltage and increase the current C to increase the voltage and decrease the current D to increase the voltage and increase the current

1 marks

Answer: C

This question in 0973/21 Oct/Nov 2025