Electromagnetic effects — Paper 2 · IGCSE Physical Science 0652

39 The diagram represents a transformer. soft-iron core input output (primary coil) (secondary coil) Why is there an induced electromotive force (e.m.f.) across the secondary coil? A There is a changing magnetic field in the soft-iron core. B There is a direct current in the primary coil. C There is a direct current in the soft-iron core. D There is a steady magnetic field in the soft-iron core.

1 marks

Answer: A

This question in 0652/21 Oct/Nov 2017

39 The diagram represents a transformer. soft-iron core input output (primary coil) (secondary coil) Why is there an induced electromotive force (e.m.f.) across the secondary coil? A There is a changing magnetic field in the soft-iron core. B There is a direct current in the primary coil. C There is a direct current in the soft-iron core. D There is a steady magnetic field in the soft-iron core.

1 marks

Answer: A

This question in 0652/22 Oct/Nov 2017

32 Why is iron a suitable material for the core of an electromagnet? A It is a good conductor of electricity. B It is a poor conductor of electricity. C It loses its magnetism when the current is switched off. D It stays magnetised when the current is switched off.

1 marks

Answer: C

This question in 0652/21 Oct/Nov 2018

37 The diagrams show two forces acting on the coil of an electric motor. In which diagram do the two forces cause the coil to rotate? A B N S N S axis coil C D N S N S

1 marks

Answer: C

This question in 0652/21 Oct/Nov 2018

38 The diagram shows a magnet being moved slowly downwards into a stationary coil to induce an e.m.f. across a voltmeter. S N V Which change does not induce a larger e.m.f.? A keeping the magnet stationary and moving the coil upwards quickly B moving both the magnet and the coil downwards at the same speed C using a stationary coil with a larger number of turns and moving the magnet at the same speed D using a stronger magnet and moving it more quickly

1 marks

Answer: B

This question in 0652/21 Oct/Nov 2018

37 The diagrams show two forces acting on the coil of an electric motor. In which diagram do the two forces cause the coil to rotate? A B N S N S axis coil C D N S N S

1 marks

Answer: C

This question in 0652/22 Oct/Nov 2018

38 The diagram shows a magnet being moved slowly downwards into a stationary coil to induce an e.m.f. across a voltmeter. S N V Which change does not induce a larger e.m.f.? A keeping the magnet stationary and moving the coil upwards quickly B moving both the magnet and the coil downwards at the same speed C using a stationary coil with a larger number of turns and moving the magnet at the same speed D using a stronger magnet and moving it more quickly

1 marks

Answer: B

This question in 0652/22 Oct/Nov 2018

37 In a transformer, how is an e.m.f. induced across the secondary coil? A The primary coil and the secondary coil are connected in parallel. B The primary coil and the secondary coil are connected in series. C The primary coil produces a changing magnetic field that links to the secondary coil. D The primary coil produces a constant magnetic field that links to the secondary coil.

1 marks

Answer: C

This question in 0652/21 Oct/Nov 2019

38 A current-carrying coil experiences a turning effect when it is placed in a magnetic field. Which row gives two changes to the coil that each result in a greater turning effect? number of turns current in on the coil the coil A decreases decreases B decreases increases C increases decreases D increases increases

1 marks

Answer: D

This question in 0652/21 Oct/Nov 2019

37 In a transformer, how is an e.m.f. induced across the secondary coil? A The primary coil and the secondary coil are connected in parallel. B The primary coil and the secondary coil are connected in series. C The primary coil produces a changing magnetic field that links to the secondary coil. D The primary coil produces a constant magnetic field that links to the secondary coil.

1 marks

Answer: C

This question in 0652/22 Oct/Nov 2019

38 A current-carrying coil experiences a turning effect when it is placed in a magnetic field. Which row gives two changes to the coil that each result in a greater turning effect? number of turns current in on the coil the coil A decreases decreases B decreases increases C increases decreases D increases increases

1 marks

Answer: D

This question in 0652/22 Oct/Nov 2019

38 The graph shows the variation with time of the voltage output of an a.c. generator. 2.0 voltage / V 1.0 0 time / ms 0 1.0 2.0 3.0 4.0 5.0 –1.0 –2.0 What is the frequency of the a.c. voltage? A 0.50 Hz B 1.0 Hz C 500 Hz D 1000 Hz

1 marks

Answer: C

This question in 0652/22 Oct/Nov 2020

39 What is the difference between alternating current (a.c.) and direct current (d.c.)? A a.c. changes direction but d.c. does not. B a.c. causes a magnetic field but d.c. does not. C a.c. transfers energy in a resistor but d.c. does not. D a.c. has a constant magnitude but d.c. does not.

1 marks

Answer: A

This question in 0652/21 Oct/Nov 2021

33 Which metal is used to make the core of an electromagnet? A aluminium B copper C iron D steel

1 marks

Answer: C

This question in 0652/21 Oct/Nov 2022

33 Which metal is used to make the core of an electromagnet? A aluminium B copper C iron D steel

1 marks

Answer: C

This question in 0652/22 Oct/Nov 2022

34 Which metal is used to make the core of an electromagnet and what is a property of an electromagnet? metal used property of electromagnet for core A soft iron it can be switched on and off B soft iron it is a permanent magnet C steel it can be switched on and off D steel it is a permanent magnet

1 marks

Answer: A

This question in 0652/21 Oct/Nov 2023

37 What is the purpose of the split-ring commutator in a d.c. motor? A to prevent the current in the coil from becoming too large B to reverse the current in the coil every half-turn C to reverse the poles of the magnet every turn D to step up the potential difference across the coil

1 marks

Answer: B

This question in 0652/21 Oct/Nov 2023

34 Which metal is used to make the core of an electromagnet and what is a property of an electromagnet? metal used property of electromagnet for core A soft iron it can be switched on and off B soft iron it is a permanent magnet C steel it can be switched on and off D steel it is a permanent magnet

1 marks

Answer: A

This question in 0652/22 Oct/Nov 2023

37 What is the purpose of the split-ring commutator in a d.c. motor? A to prevent the current in the coil from becoming too large B to reverse the current in the coil every half-turn C to reverse the poles of the magnet every turn D to step up the potential difference across the coil

1 marks

Answer: B

This question in 0652/22 Oct/Nov 2023

36 A magnet is pushed towards a coil of wire. An electromotive force (e.m.f.) is induced across the ends of the coil. coil N S magnet The induced e.m.f. causes a force to act on the magnet. In which direction does this force act on the magnet? A downwards B upwards C to the left D to the right

1 marks

Answer: D

This question in 0652/21 Oct/Nov 2024

37 A transformer is 100% efficient. The transformer has 20 turns on the primary coil and 60 turns on the secondary coil. The primary coil is connected to a 12 V a.c. supply. soft-iron core input output voltage voltage 12 V a.c. primary coil secondary coil 20 turns 60 turns What is the output voltage? A 0.010 V B 4.0 V C 36 V D 100 V

1 marks

Answer: C

This question in 0652/21 Oct/Nov 2024