Electromagnetic effects — Paper 2 · IGCSE Physics (9-1) 0972

34 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 0972/21 May/June 2018

35 The diagram shows a current-carrying conductor in a magnetic field. Which arrow shows the direction of the force acting on the conductor? A S N D B C

1 marks

Answer: A

This question in 0972/21 May/June 2018

36 Power losses in transmission cables are reduced by increasing the transmission voltage. What is the explanation for this reduction? A The current decreases, reducing thermal energy losses. B The current increases, increasing the flow of charge. C The resistance of the cable increases, reducing the current. D The resistance of the cable decreases.

1 marks

Answer: A

This question in 0972/21 May/June 2018

27 A bar magnet is placed inside a current-carrying coil. The diagram shows four different experiments. 1 2 magnet slowly magnet slowly removed removed + – 3 4 current in coil current in coil slowly reduced slowly reduced + – In which experiments is the magnet demagnetised? A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

1 marks

Answer: B

This question in 0972/21 Oct/Nov 2018

35 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 0972/21 Oct/Nov 2018

36 A wire is placed in a strong magnetic field. When a current is passed through the wire it moves upwards, as shown. S N movement The current is reversed. In which direction does the wire move? A downwards B towards the north pole C towards the south pole D upwards

1 marks

Answer: A

This question in 0972/21 Oct/Nov 2018

26 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 0972/21 May/June 2019

36 What is the purpose of the commutator in a d.c. electric motor? A to control the speed at which the motor rotates B to reverse the direction of the voltage across the power supply every half-turn C to reverse the direction of the current in the motor coil every half-turn D to reverse the direction of spin of the motor coil every half-turn

1 marks

Answer: C

This question in 0972/21 May/June 2019

37 The diagram shows a wire between two magnetic poles. The wire is connected in a circuit with an ammeter. wire N S A The wire is moved downwards, towards the bottom of the page. A current is induced in the wire. In which direction is the force on the wire caused by this current? A towards the bottom of the page B towards the left of the page C towards the right of the page D towards the top of the page

1 marks

Answer: D

This question in 0972/21 May/June 2019

39 A radioactive source emits α-particles, β-particles and γ-rays into a vacuum where there is a magnetic field. The magnetic field acts perpendicularly into the plane of the paper. The paths X, Y and Z of the three types of radiation through the magnetic field are shown. Y X magnetic field into paper Z radioactive source Which radiation follows path X, path Y and path Z? X Y Z A α-particles β-particles γ-rays B α-particles γ-rays β-particles C β-particles α-particles γ-rays D β-particles γ-rays α-particles

1 marks

Answer: B

This question in 0972/21 May/June 2019

36 The diagram shows a current-carrying wire placed between two magnetic poles. The current is in the direction shown. wire S N current direction What is the direction of the force on the wire? A towards the bottom of the page B towards the top of the page C towards the left-hand side of the page D towards the right-hand side of the page

1 marks

Answer: A

This question in 0972/22 May/June 2019

37 Diagram 1 shows an a.c. generator. The coil is turning as shown. diagram 1 coil N S Diagram 2 shows the output voltage produced by the generator as the coil turns. Which point on diagram 2 shows the voltage induced when the coil is moving through the position shown in diagram 1? diagram 2 output A voltage B 0 0 C time D

1 marks

Answer: B

This question in 0972/22 May/June 2019

34 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 0972/21 Oct/Nov 2019

35 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 0972/21 Oct/Nov 2019

36 Diagram 1 shows a coil of wire P between the poles of a magnet. The ends of coil P are connected to a battery by slip rings. Diagram 2 shows a coil of wire Q between the poles of a different magnet. The ends of coil Q are connected to a battery by a split-ring commutator. P Q N S N S diagram 1 diagram 2 What happens to coils P and Q? coil P coil Q A continuously turns makes one quarter turn anticlockwise anticlockwise then stops B continuously turns makes one quarter turn clockwise clockwise then stops C makes one quarter turn continuously turns anticlockwise then stops anticlockwise D makes one quarter turn continuously turns clockwise then stops clockwise

1 marks

Answer: C

This question in 0972/21 Oct/Nov 2019

39 The diagram shows β-particles being directed between the poles of a magnet. N β-particles S In which direction will the particles be deflected? A into the page B out of the page C towards the bottom of the page D towards the top of the page

1 marks

Answer: B

This question in 0972/21 Oct/Nov 2019

27 The circuit shows one method of magnetising a steel bar. + – steel bar How can the circuit be altered so that it can be used to demagnetise the magnetised steel bar? A remove the steel bar from the coil whilst the current is switched on B replace the d.c. supply with an a.c. supply and gradually reduce the supply voltage to zero C reverse the polarity of the d.c. supply D reverse the polarity of the d.c. supply and gradually reduce the supply voltage to zero

1 marks

Answer: B

This question in 0972/21 May/June 2020

34 The diagram shows a wire between the poles of a magnet. The wire is perpendicular to the page. N wire LEFT RIGHT S The wire is moved and a current is induced upwards, out of the paper. In which direction is the wire moved? A left to right B right to left C up the page D down the page

1 marks

Answer: B

This question in 0972/21 May/June 2020

35 A 100% efficient transformer converts a 240 V input voltage to a 12 V output voltage. The output power of the transformer can be a maximum of 20 W. The output is connected to two 0.30 A bulbs in parallel. One of the bulbs fails. How does the current in the primary coil change? A It decreases by 0.30 A. B It decreases by 0.015 A. C It increases by 0.15 A. D It remains unchanged.

1 marks

Answer: B

This question in 0972/21 May/June 2020

36 Cables transmit electrical power from the output of the transformer at a power station to the input of the transformer at a substation. cables output input transformer at transformer at power station substation The power at the output of the transformer at the power station is 400 MW. Which situation delivers the most power to the input of the transformer at the substation? potential difference at power station transformer diameter of cables output / kV A 200 large B 200 small C 400 large D 400 small

1 marks

Answer: C

This question in 0972/21 May/June 2020

27 A student wants to demagnetise a steel bar. He uses the apparatus shown. He switches on the circuit for a few seconds and then switches off. He finds that the steel bar is still magnetised. steel bar coil a.c. supply What should he do to improve his method? A change the supply from an alternating to a direct voltage B use a lower alternating voltage C remove the steel bar from the coil whilst the circuit is switched on D use a coil that has fewer turns on it

1 marks

Answer: C

This question in 0972/22 May/June 2020

35 The diagram shows the magnetic field due to a current in a solenoid. Where is the magnetic field the strongest? A D B C

1 marks

Answer: C

This question in 0972/22 May/June 2020

36 A beam of electrons is passed through the magnetic field of a magnet. How must the magnet be positioned to deflect the beam in the direction shown? A B e– e– N S direction S of beam direction N of beam C D e– e– S N direction N of beam direction S of beam

1 marks

Answer: B

This question in 0972/22 May/June 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 0972/21 Oct/Nov 2020

36 The diagram shows part of a long current-carrying conductor. At which point is the magnetic field strongest? A C D B

1 marks

Answer: C

This question in 0972/21 Oct/Nov 2020

37 A beam of particles moves through a magnetic field. In which situation do the particles experience a magnetic force? A a beam of -particles moving parallel to the magnetic field lines B a beam of electrons moving parallel to the magnetic field lines C a beam of -particles moving perpendicularly across the magnetic field lines D a beam of neutrons moving perpendicularly across the magnetic field lines

1 marks

Answer: C

This question in 0972/21 Oct/Nov 2020

34 What is the function of the split-ring commutator in an electric motor with a single rotating coil? A to enable the motor to function with an a.c. source B to reverse the current in the coil once every revolution C to reverse the current in the coil whenever its plane becomes perpendicular to the magnetic field D to reverse the current in the coil whenever its plane is parallel with the magnetic field

1 marks

Answer: C

This question in 0972/21 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 0972/21 Oct/Nov 2021

36 The diagrams show a horizontal wire in a magnetic field. The horizontal wire is firmly held at each end (not shown) and cannot move. The magnets and holder are on a balance. When there is no current in the wire, the reading on the balance is 0.35 g. fixed horizontal wire current direction N S balance N S 0.35 g fixed horizontal wire view from side view from above There is a d.c. current in the wire, as shown. What happens to the reading on the balance? A smaller than 0.35 g B no change C changing from smaller to larger than 0.35 g repeatedly D larger than 0.35 g

1 marks

Answer: D

This question in 0972/21 Oct/Nov 2021

28 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 0972/21 May/June 2022

35 A magnet is dropped vertically through a solenoid. This induces magnetic poles at both ends of the solenoid. N X X S N S N S diagram 1 diagram 2 diagram 3 Which magnetic poles are induced at position X in diagram 1 and diagram 3? diagram 1 diagram 3 A N pole N pole B N pole S pole C S pole N pole D S pole S pole

1 marks

Answer: C

This question in 0972/21 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 0972/21 May/June 2022

37 What is the purpose of the split-ring commutator in an electric motor? A to ensure that the magnetic field in the motor changes direction every half rotation B to ensure that the magnetic field in the motor stays in the same direction at all times C to ensure that the turning effect on the motor changes direction every half rotation D to ensure that the turning effect on the motor stays in the same direction at all times

1 marks

Answer: D

This question in 0972/21 May/June 2022

40 The diagram shows a stream of B-particles travelling in a line that passes between the poles of a magnet. Oo B-particles In which direction will the B-particles be deflected by the magnet? A __ towards the N pole B_ towards the S pole C into the page D out of the page

1 marks

Answer: D

This question in 0972/21 May/June 2022

35 A coil XY is wound around a cardboard tube. When the S pole of a magnet is pushed into the coil XY, the galvanometer deflects to the left. X Y cardboard tube N S S pole moves in What other movement of the magnet will produce a deflection to the left? A B X Y X Y N S N S S pole N pole moves out moves out C D X Y X Y S N S N N pole S pole moves in moves out

1 marks

Answer: D

This question in 0972/22 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 0972/22 May/June 2022

37 The diagram shows a current-carrying wire in a magnetic field. current N S LEFT RIGHT In which direction is the force acting on the wire? A towards the bottom of the page B to the left C to the right D towards the top of the page

1 marks

Answer: A

This question in 0972/22 May/June 2022

34 The diagram represents a transformer. core primary coil Which row shows materials suitable for making the core and the primary coil? core primary coil A iron copper B iron plastic C steel copper D steel plastic

1 marks

Answer: A

This question in 0972/21 Oct/Nov 2022

35 The diagrams show the magnetic field lines around a wire carrying a current, I. 1 2 I I 3 4 I I Which diagrams are correct? A 1 only B 2 and 3 C 4 only D 1 and 3

1 marks

Answer: D

This question in 0972/21 Oct/Nov 2022

36 Which statement about electromagnetic induction is correct? A A conductor moving parallel to magnetic field lines induces an electromotive force (e.m.f.) in the conductor. B The direction of the induced electromotive force (e.m.f.) opposes the change which produces it. C The induced current is in a direction parallel to the direction of motion producing it. D The induced electromotive force (e.m.f.) decreases when the speed of the conductor moving across the field lines increases.

1 marks

Answer: B

This question in 0972/21 Oct/Nov 2022

30 The diagram shows an a.c. generator. N S Y V X The graph shows the potential difference (p.d.) between points X and Y plotted against time. A positive value of p.d. indicates that X is more positive than Y. p.d. between X and Y 0 0 time P Which diagram shows the position of the coil at point P on the graph? A B C D Y Y Y Y X X X X

1 marks

Answer: C

This question in 0972/21 May/June 2023

31 An electron moves into a uniform magnetic field. The arrow shows the initial direction of motion of the electron. The direction of the magnetic field is into the plane of the page. uniform magnetic field electron In which direction does a force act on the electron when it enters the magnetic field? A into the page B out of the page C towards the bottom of the page D towards the top of the page

1 marks

Answer: C

This question in 0972/21 May/June 2023

32 Which statement about a transformer is correct? A There is an alternating current in the iron core from the primary coil to the secondary coil. B An alternating current in the iron core induces an alternating current in the secondary coil. C An alternating current in the primary coil induces a direct current in the secondary coil. D An alternating current in the primary coil induces an alternating voltage across the secondary coil.

1 marks

Answer: D

This question in 0972/21 May/June 2023

30 A step-down transformer is 100% efficient. It has an input voltage of 240 V a.c. and an output voltage of 60 V a.c. The current in the primary coil is 0.50 A. What is the current in the secondary coil? A 0.13 A B 0.50 A C 2.0 A D 8.0 A

1 marks

Answer: C

This question in 0972/22 May/June 2023

31 The diagram shows the pattern of the magnetic field due to the current I in a straight wire. I Y Q P X Which row is correct? relative direction of field strength of field A X greater at P than Q B Y greater at P than Q C X greater at Q than P D Y greater at Q than P

1 marks

Answer: D

This question in 0972/22 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 0972/22 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 0972/21 Oct/Nov 2023

31 A current in a solenoid produces a uniform magnetic field inside the solenoid. The magnetic field direction is due east. Which changes will produce a stronger magnetic field with a direction due west? A Use a smaller current and turn the solenoid through 180. B Use a smaller current and reverse the current. C Use a larger current and turn the solenoid through 90. D Use a larger current and reverse the current.

1 marks

Answer: D

This question in 0972/21 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 0972/21 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 0972/21 Oct/Nov 2023

28 When a conductor in a complete circuit cuts across a magnetic field, a current is induced in the conductor. Which statement about the induced current is correct? A The induced current is in the same direction as the motion of the conductor. B The induced current is in the opposite direction to the motion of the conductor. C The direction of the induced current is in the same direction as the magnetic field. D The direction of the induced current opposes the change causing it.

1 marks

Answer: D

This question in 0972/21 May/June 2024

29 The diagram shows a solenoid carrying an electric current. X X Y Y Z Z Which row compares the strength of the magnetic field due to the solenoid at points Y and Z with the strength of the magnetic field at point X? magnetic field magnetic field strength at Y strength at Z A equal to X less than X B equal to X greater than X C greater than X less than X D greater than X greater than X

1 marks

Answer: A

This question in 0972/21 May/June 2024

30 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 When the current is towards the top of the page and the direction of the magnetic field is unchanged, the force produced acts into the page. 2 When the current is towards the bottom of the page and the magnetic field is reversed, the force produced acts into the page. 3 When the current in the wire is alternating, the wire vibrates into and out of the page. Which statements are correct? A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

1 marks

Answer: A

This question in 0972/21 May/June 2024

31 Which types of electric current are in the primary coil and the secondary coil of a step-up transformer? primary secondary coil coil A a.c. a.c. B a.c. d.c. C d.c. a.c. D d.c. d.c.

1 marks

Answer: A

This question in 0972/21 May/June 2024

31 The diagram shows a simple a.c. generator. The magnet rotates around a fixed coil wound round a fixed iron core. The electromotive force (e.m.f.) output is a sine wave, a series of crests, zeros and troughs. The magnet is shown in three positions, P, Q and R, during its rotation. The magnetic field in the coil is zero at Q but changing most rapidly. position P position Q position R magnet N S S N fixed coil Which statement about the induced e.m.f. in the coil is correct? A The magnitude of the e.m.f. at position Q is larger than that at position P. B The magnitude of the e.m.f. at position Q is zero. C The magnitude of the e.m.f. at position Q is smaller than at position R, but not zero. D The magnitude of the e.m.f. at position R is larger than at position P.

1 marks

Answer: A

This question in 0972/22 May/June 2024

32 A 24 V power supply and a 100% efficient transformer are used to light a 6.0 V, 12 W lamp. What is the current in the power supply? A 0.50 A B 2.0 A C 3.0 A D 8.0 A

1 marks

Answer: A

This question in 0972/22 May/June 2024

31 A metal rod, XY, is placed in a magnetic field so that it is perpendicular to the field, as shown. X Y In which direction is the rod moved so that there is an induced current from Y to X? A left to right B right to left C into the paper, away from the observer D out of the paper, towards the observer

1 marks

Answer: D

This question in 0972/21 Oct/Nov 2024

32 The diagram shows a basic electric motor. X N S Y Z What are the names of the features? X Y Z A axle battery brushes B coil brushes commutator C generator wires transformer D solenoid connectors switch

1 marks

Answer: B

This question in 0972/21 Oct/Nov 2024

33 Two transformers, P and Q, each have 2000 turns on their primary coils and 1000 turns on their secondary coils. Both transformers are 100% efficient. The secondary of transformer P is connected to the primary of transformer Q. Q provides a motor with a current of 0.2 A. What is the current being supplied to the primary of transformer P? A 0.8 A B 0.4 A C 0.1 A D 0.05 A

1 marks

Answer: D

This question in 0972/21 Oct/Nov 2024

29 A wire connected to a resistor R is moved in a magnetic field. A current is induced in the direction shown. In which direction is the wire moved? wire A D B B N S R C induced current

1 marks

Answer: C

This question in 0972/21 May/June 2025

30 Which component is not found in an a.c. generator? A coil of wire B split-ring commutator C magnetic poles D slip rings

1 marks

Answer: B

This question in 0972/21 May/June 2025

31 There is a current in a straight metal wire in the direction shown. direction of current Which row describes the direction and the pattern of the magnetic field due to the wire when looking from vertically above the wire? direction pattern A anticlockwise circular B left to right parallel lines C clockwise circular D right to left parallel lines

1 marks

Answer: A

This question in 0972/21 May/June 2025

32 A simple transformer contains an iron core. What is the function of the iron core in the transformer? A to conduct current from the primary coil to the secondary coil B to enable the secondary coil to act as an electromagnet C to ensure there is a high voltage between the primary coil and the secondary coil D to link the magnetic field in the primary coil to the secondary coil

1 marks

Answer: D

This question in 0972/21 May/June 2025

30 The lamps on a bicycle are powered by a simple electrical generator. A permanent magnet rotates around a stationary coil of wire wound on an iron core. Which statement is correct? A The current in the lamps decreases as the speed of rotation increases. B The current in the lamps decreases when the magnet is replaced by a stronger magnet. C The output electromotive force (e.m.f.) will be higher if the gap between the magnet and the coil is bigger. D The output e.m.f. will be higher if there are more turns on the coil.

1 marks

Answer: D

This question in 0972/21 Oct/Nov 2025

31 A current-carrying coil in the magnetic field between the poles of two magnets experiences a turning effect. Which change would decrease the turning effect? A decreasing the distance between the magnets B increasing the current in the coil C using stronger magnets D decreasing the number of turns on the coil

1 marks

Answer: D

This question in 0972/21 Oct/Nov 2025

32 Cables transmit electrical power from the output of the transformer at a power station to the input of another transformer at a substation. cables output input transformer at transformer at power station substation The power at the output of the transformer at the power station is 400 MW. Which situation delivers the most power to the input of the transformer at the substation? potential difference at power station transformer diameter of cables output / kV A 200 large B 200 small C 400 large D 400 small

1 marks

Answer: C

This question in 0972/21 Oct/Nov 2025