Electromagnetic effects — Paper 1 · IGCSE Physics (9-1) 0972

28 Which metal is used for the core of an electromagnet? A copper B iron C magnesium D steel

1 marks

Answer: B

This question in 0972/11 May/June 2018

35 Which statement about electromagnetic induction is correct? A A strong magnet that is held stationary near a stationary conductor causes a greater effect than a weak magnet. B The effect occurs when a magnet and a conductor are both moved with the same speed and in the same direction. C The effect occurs when a magnet is moved away from a nearby conductor. D The effect only occurs when a magnet is moved towards a conductor.

1 marks

Answer: C

This question in 0972/11 May/June 2018

36 An electrical device changes the voltage of an electrical supply from 240 V a.c. to 20 V a.c. What is this device? A a generator B a relay C a transformer D a voltmeter

1 marks

Answer: C

This question in 0972/11 May/June 2018

28 Why is soft iron used for the core of an electromagnet? A Soft iron easily becomes a permanent magnet. B Soft iron is a good electrical conductor. C Soft iron is a poor thermal conductor. D Soft iron loses its magnetism when the current in the coil is switched off.

1 marks

Answer: D

This question in 0972/11 May/June 2019

36 A bar magnet is held near a coil of wire. The coil is connected to a sensitive voltmeter. coil of wire bar magnet N V The N-pole of the magnet is moved quickly towards the coil. The voltmeter shows a reading of +10 mV. The N-pole of the magnet is then moved slowly away from the same end of the coil. The reading on the voltmeter is observed. Which voltmeter reading is possible? A –15 mV B –5 mV C 0 mV D +5 mV

1 marks

Answer: B

This question in 0972/11 May/June 2019

37 Four small compasses are placed around a solenoid. solenoid A current is now switched on in the solenoid. Which diagram shows possible new directions of the compass needles? A B C D

1 marks

Answer: D

This question in 0972/11 May/June 2019

28 Two soft-iron rods are placed end-to-end inside a coil. The coil is connected to a battery. coil soft-iron rod soft-iron rod The connections from the battery to the coil are now reversed. What happens to the soft-iron rods in each case? battery connections battery connections as shown reversed A rods attract rods attract B rods attract rods repel C rods repel rods attract D rods repel rods repel

1 marks

Answer: A

This question in 0972/11 Oct/Nov 2019

35 A student investigates the output voltage induced across a coil of wire by a bar magnet. When will the induced voltage have the greatest value? A The student slowly moves the bar magnet into the coil of wire. B The student leaves the bar magnet stationary in the coil of wire. C The student quickly removes the bar magnet from the coil of wire. D The student places the bar magnet at rest outside the coil of wire.

1 marks

Answer: C

This question in 0972/11 Oct/Nov 2019

36 There is a current in a wire. The direction of the current is out of the page. Which diagram shows the magnetic field pattern produced? A B key wire carrying a current out of the page C D

1 marks

Answer: B

This question in 0972/11 Oct/Nov 2019

35 A transformer has 200 turns on its primary coil and is connected to a 240 V a.c. supply. The output voltage of the transformer is 60 V a.c.. How many turns are on the secondary coil of the transformer? A 20 B 50 C 72 D 800

1 marks

Answer: B

This question in 0972/11 May/June 2020

36 A conducting wire is placed between the poles of a magnet. When an electric current in the wire is in the direction shown, then the force on the wire acts out of the page. wire N S Three statements of different conditions and how the wire is affected are given. 1 The current is towards the top of the page and the direction of the magnetic field is unchanged then the force produced acts into the page. 2 The current is towards the bottom of the page and the magnetic field is reversed then the force produced acts into the page. 3 The current in the wire is alternating and the wire vibrates into and out of the page. Which statements are correct? A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3

1 marks

Answer: D

This question in 0972/11 May/June 2020

35 The diagrams P, Q and R show three voltage–time graphs. diagram P diagram Q + + voltage voltage 0 0 0 time 0 time – – diagram R + voltage 0 0 time – Which graphs show an alternating voltage? A P and Q only B P and R only C Q and R only D P, Q and R

1 marks

Answer: D

This question in 0972/12 May/June 2020

36 The diagram shows a transformer. core primary coil secondary coil 40 turns 40 000 turns Which statement about this transformer is correct? A It can operate from a 12 V battery. B It has a core which is made of steel. C It steps the input voltage up by a factor of 1000. D It steps the input voltage down by a factor of 1000.

1 marks

Answer: C

This question in 0972/12 May/June 2020

34 An electromagnet is positioned close to a coil of wire. electromagnet coil The electromagnet is switched on, remains on for a short time, and is then switched off. Three statements about the pointer on the galvanometer during this sequence are given. 1 The pointer kicks to one side as the electromagnet is switched on. 2 The pointer records a steady non-zero value while the electromagnet remains switched on. 3 The pointer kicks to the other side as the electromagnet is switched off. Which statements are correct? A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3

1 marks

Answer: B

This question in 0972/11 Oct/Nov 2020

35 A transformer is needed to convert a supply of 240 V a.c. into 4800 V a.c.. NP NS 240 V a.c. 4800 V a.c. Which pair of coils would be suitable for this transformer? number of turns number of turns on primary coil NP on secondary coil NS A 50 1 000 B 240 48 000 C 480 24 D 2000 100

1 marks

Answer: A

This question in 0972/11 Oct/Nov 2020

36 The diagrams show a current-carrying wire with an arrow in the direction of the current. Which diagram shows the magnetic field produced by the current? A B magnetic magnetic field lines field lines wire wire C D magnetic magnetic field lines field lines wire wire

1 marks

Answer: B

This question in 0972/11 Oct/Nov 2020

8 Electrical energy may be obtained from nuclear fission. In which order is the energy transferred in this process? A nuclear fuel  generator  reactor and boiler  turbines B nuclear fuel  generator  turbines  reactor and boiler C nuclear fuel  reactor and boiler  generator  turbines D nuclear fuel  reactor and boiler  turbines  generator

1 marks

Answer: D

This question in 0972/11 Oct/Nov 2021

29 The step-down transformer shown reduces mains voltage to 12 V. copper wire soft-iron core mains 12 V voltage When the transformer is used, some energy is transferred to the surroundings. Which type of energy is transferred to the surroundings? A chemical energy B light energy C thermal energy D elastic energy

1 marks

Answer: C

This question in 0972/11 Oct/Nov 2021

35 Which graph represents an alternating current (a.c.)? A B current current 0 0 0 time 0 time C D current current 0 0 0 time 0 time

1 marks

Answer: A

This question in 0972/11 Oct/Nov 2021

27 A student counts how many iron pins an electromagnet picks up when its power supply is switched on. Then, she counts how many pins are picked up when the power supply is switched off. core d.c. power d.c. power supply on supply off iron pins She repeats the experiment using cores made of different materials. The results are shown. Which core is made out of soft iron? pins picked up with pins picked up with the power supply on the power supply off A 0 0 B 2 7 C 8 5 D 12 0

1 marks

Answer: D

This question in 0972/11 May/June 2022

35 Which transformer can change a 240 V a.c. input into a 15 V a.c. output? A B 800 turns 40 turns 1000 turns 25 turns C D 2400 turns 15 turns 1200 turns 75 turns

1 marks

Answer: D

This question in 0972/11 May/June 2022

36 The diagrams show patterns around a straight wire carrying a current perpendicularly out of the page. Which pattern represents the magnetic field due to the current in the wire? A B C D

1 marks

Answer: B

This question in 0972/11 May/June 2022

37 A current-carrying coil in a magnetic field experiences a turning effect. Three suggestions for increasing the turning effect are given. 1 Increase the number of turns on the coil. 2 Increase the current in the coil. 3 Increase the strength of the magnetic field. Which suggestions are correct? A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3

1 marks

Answer: D

This question in 0972/11 May/June 2022

35 Electrical power is transmitted from power stations to homes using the National Grid. In which part of the National Grid is the voltage highest? B A C D step-up step-down step-down transformer transformer transformer power houses station

1 marks

Answer: B

This question in 0972/12 May/June 2022

36 Which transformer can change a 240 V a.c. input into a 15 V a.c. output? A B 800 turns 40 turns 1000 turns 25 turns C D 2400 turns 15 turns 1200 turns 75 turns

1 marks

Answer: D

This question in 0972/12 May/June 2022

37 The coils in two electric motors are identical in size, but motor 1 is observed to spin more quickly than motor 2. Three suggestions are made to explain this observation. 1 The current in the coil of motor 1 is greater than the current in the coil of motor 2. 2 The number of turns on the coil of motor 1 is greater than on the coil of motor 2. 3 The magnets in motor 1 are stronger than the magnets in motor 2. Which suggestions give a possible explanation for this observation? A 1 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3

1 marks

Answer: D

This question in 0972/12 May/June 2022

31 A simple electric generator induces an electromotive force (e.m.f.). Which modification would increase the induced e.m.f.? A Increase the number of turns in the coil of the generator. B Increase the distance between the magnetic poles. C Reduce the strength of the magnetic field around the coil. D Reverse the direction of the magnetic field.

1 marks

Answer: A

This question in 0972/11 May/June 2023

32 The diagram shows a vertical wire carrying a current I placed between the poles of a magnet. I N S What is the direction of the force on the wire exerted by the magnetic field? A from N to S B from S to N C horizontal and at right angles to the direction from N to S D parallel to the wire

1 marks

Answer: C

This question in 0972/11 May/June 2023

33 What is an advantage of transmitting electricity at a high voltage? A It is faster. B It is safer. C Less energy is wasted. D Less equipment is needed.

1 marks

Answer: C

This question in 0972/11 May/June 2023

31 A student investigates the output voltage induced across a coil of wire by a bar magnet. When will the induced voltage have the greatest value? A The student slowly moves the bar magnet into the coil of wire. B The student leaves the bar magnet stationary in the coil of wire. C The student quickly removes the bar magnet from the coil of wire. D The student places the bar magnet at rest outside the coil of wire.

1 marks

Answer: C

This question in 0972/12 May/June 2023

32 In which device is the magnetic effect of a current not used? A electromagnet B loudspeaker C potential divider D relay

1 marks

Answer: C

This question in 0972/12 May/June 2023

33 The diagram represents the transmission of electricity from a power station to homes that are many kilometres away. Two transformers are labelled X and Y. transmission pylon cables pylon cables large houses power ground station X distance Y What type of transformers are X and Y? X Y A step-down transformer step-down transformer B step-down transformer step-up transformer C step-up transformer step-down transformer D step-up transformer step-up transformer

1 marks

Answer: C

This question in 0972/12 May/June 2023

24 Which metal could be used for a permanent magnet and which metal could be used for the core of an electromagnet? permanent core of magnet electromagnet A iron copper B iron steel C steel copper D steel iron

1 marks

Answer: D

This question in 0972/11 Oct/Nov 2023

31 A teacher sets up the equipment for three demonstrations, P, Q and R. P Q magnet coil soft-iron rod coil 1 coil 2 S N V V R copper rod S N V In demonstration P, the magnet is moved to the right. In demonstration Q, the switch is closed. In demonstration R, the copper rod is moved vertically upwards. Which demonstrations can be used to demonstrate electromagnetic induction? A P and Q only B P and R only C Q and R only D P, Q and R

1 marks

Answer: D

This question in 0972/11 Oct/Nov 2023

32 A metal rod PQ rests on two horizontal metal wires that are attached to a battery. The rod lies between the poles of a magnet. magnet N Q metal rod P S magnet When the switch is closed, the rod moves to the right. What could be changed so that the rod moves to the left? A Open the switch. B Reverse the battery terminals and exchange the poles of the magnet. C Reverse the battery terminals but without exchanging the poles of the magnet. D Turn the metal rod around (P and Q exchanged).

1 marks

Answer: C

This question in 0972/11 Oct/Nov 2023

33 A transformer in a computer is used to transform the mains voltage of 240 V to 12 V. The number of turns on the secondary coil is 2000. Which statement about the transformer is correct? A It is a step-down transformer and has 100 turns on its primary coil. B It is a step-down transformer and has 40 000 turns on its primary coil. C It is a step-up transformer and has 100 turns on its primary coil. D It is a step-up transformer and has 40 000 turns on its primary coil.

1 marks

Answer: B

This question in 0972/11 Oct/Nov 2023

30 A student moves a magnet into a coil, as shown. The voltmeter measures the magnitude of the electromotive force (e.m.f.) induced in the coil. coil S N magnet V Which quantity does not affect the magnitude of the induced e.m.f.? A the number of turns per unit length in the coil B the polarity of the magnet C the speed of the magnet D the strength of the magnet

1 marks

Answer: B

This question in 0972/11 May/June 2024

31 A student makes a small d.c. motor. The teacher supplies the following equipment. ● battery ● ammeter ● voltmeter ● coil of wire ● magnets ● resistor The student is also able to use other equipment if he wishes. Which equipment must be used? A ammeter, battery and resistor B ammeter, coil of wire and voltmeter C battery, coil of wire and magnets D magnets, resistor and voltmeter

1 marks

Answer: C

This question in 0972/11 May/June 2024

25 A metal bar is placed inside a current-carrying coil, as shown in diagram 1. There is a small current in the coil. The bar holds a few nails, as shown in diagram 2. nails diagram 1 diagram 2 When there is no current in the coil, the nails drop off. Which row is correct? metal from which effect of a larger the bar is made current in the coil A soft iron it makes no difference B soft iron the bar holds more nails C steel it makes no difference D steel the bar holds more nails

1 marks

Answer: B

This question in 0972/12 May/June 2024

31 Which graph does not show the correct trend for the force F causing the turning effect on the coil in a d.c. motor? A B F F 0 0 0 number of turns 0 current on the coil C D F F 0 0 0 strength of the 0 weight of magnetic field the motor

1 marks

Answer: D

This question in 0972/12 May/June 2024

31 The diagrams show a strong magnet and a weak magnet moving into the same coil of wire at different speeds. arrangement X arrangement Y strong magnet weak magnet N S N S moving moving slowly slowly arrangement Z strong magnet N S moving quickly Which arrangement induces the largest electromotive force (e.m.f.) and which arrangement induces the smallest e.m.f.? largest smallest e.m.f. e.m.f. A X Y B Y Z C Z X D Z Y

1 marks

Answer: D

This question in 0972/11 Oct/Nov 2024

32 The diagrams show a current-carrying wire with an arrow in the direction of the current. Which diagram shows the magnetic field produced by the current? A B magnetic magnetic field lines field lines wire wire C D magnetic magnetic field lines field lines wire wire

1 marks

Answer: B

This question in 0972/11 Oct/Nov 2024

33 What are the best materials to use for the construction of a transformer? A copper for the core and steel for the coils wound around it B copper for the core and copper for the coils wound around it C soft iron for the core and copper for the coils wound around it D steel for the core and copper for the coils wound around it

1 marks

Answer: C

This question in 0972/11 Oct/Nov 2024

32 A student investigates the turning effect on a current-carrying coil placed in a magnetic field. The student changes the current in the coil and the number of turns on the coil. Which two changes together must increase the turning effect? A decreasing the current and decreasing the number of turns B decreasing the current and increasing the number of turns C increasing the current and decreasing the number of turns D increasing the current and increasing the number of turns

1 marks

Answer: D

This question in 0972/11 May/June 2025

33 There is a current of 3.0 A in a conductor. The current is changed to 6.0 A in the opposite direction. Which effect does this have on the magnetic field around the conductor? A It decreases and it acts in the opposite direction. B It decreases and it acts in the same direction. C It increases and it acts in the opposite direction. D It increases and it acts in the same direction.

1 marks

Answer: C

This question in 0972/11 May/June 2025

32 The transformer in a laptop power supply is used to change mains voltage from 240 V to 20 V. The transformer has 600 turns on the secondary coil. Which type of transformer is it and how many turns does the transformer have on the primary coil? number of turns transformer type on primary coil A step-down 50 B step-down 7200 C step-up 50 D step-up 7200

1 marks

Answer: B

This question in 0972/12 May/June 2025