Electrical safety — Paper 2 · IGCSE Sciences - Co-ordinated (9-1) 0973

38 The diagram shows the connections to an electric heater. The circuit includes three fuses. heater plastic fuse 1 case live fuse 3 fuse 2 neutral Which of the fuses are correctly placed? A fuse 1, fuse 2 and fuse 3 B fuse 1 and fuse 2 only C fuse 1 only D fuse 2 only

1 marks

Answer: C

This question in 0973/22 May/June 2019

38 An electrical extension block has four sockets, a cable which can safely take a current of 6 A and a plug. It is protected by a fuse rated at 5 A. The extension block is used with four appliances and the 5 A fuse blows. The owner replaces the 5 A fuse with a 13 A fuse. Why is the extension block now dangerous? A The appliances may overheat before the fuse blows. B The cable may overheat before the fuse blows. C The sockets may burn out before the fuse blows. D The 13 A fuse may blow too soon.

1 marks

Answer: B

This question in 0973/21 Oct/Nov 2019

39 A fuse is a safety device for use in an electrical circuit. The current in the circuit becomes greater than the rated value for the fuse. What happens? A The current decreases to zero. B The current decreases to the rated value for the fuse. C The thickness of the insulation around the wires increases. D The current is sent to the outer case of the appliance.

1 marks

Answer: A

This question in 0973/21 May/June 2020

38 A fuse is a safety device for use in an electrical circuit. The current in the circuit becomes greater than the rated value for the fuse. What happens? A The current decreases to zero. B The current decreases to the rated value for the fuse. C The thickness of the insulation around the wires increases. D The current is sent to the outer case of the appliance.

1 marks

Answer: A

This question in 0973/22 May/June 2020

38 A student connects the circuit shown. fuse When the switch is closed the fuse blows and stops the current. What is a possible reason for this? A The current rating of the fuse is too high. B The current is too large. C The lamp is too dim. D The voltage is too small.

1 marks

Answer: B

This question in 0973/21 May/June 2021

38 A student connects the circuit shown. fuse When the switch is closed the fuse blows and stops the current. What is a possible reason for this? A The current rating of the fuse is too high. B The current is too large. C The lamp is too dim. D The voltage is too small.

1 marks

Answer: B

This question in 0973/22 May/June 2021

38 The current in an electric heater during normal use is 11 A. What is an appropriate rating for a fuse to protect the heater? A 3 A B 10 A C 13 A D 36 A

1 marks

Answer: C

This question in 0973/21 Oct/Nov 2022

38 Fuses are used in domestic electric circuits. Which statement about fuses is correct? A A fuse is connected in the live wire. B A fuse is connected in the neutral wire. C A 3.0 A fuse produces a current of exactly 3.0 A in the circuit. D A 3.0 A fuse produces a minimum current of 3.0 A in the circuit.

1 marks

Answer: A

This question in 0973/21 May/June 2023

39 The current in an electric kettle used to boil water is 9.0 A. What is the most appropriate rating of fuse to use with this kettle? A 1 A B 3 A C 8 A D 13 A

1 marks

Answer: D

This question in 0973/21 Oct/Nov 2023

38 What is the function of a fuse in a circuit? A It decreases the resistance of the circuit. B It ensures a constant current in the circuit. C It ensures a constant resistance in the circuit. D It prevents the cables from overheating.

1 marks

Answer: D

This question in 0973/22 May/June 2024

38 The instructions for a household lamp state that the plug must be fitted with a 3 A fuse. What happens if a 13 A fuse is fitted by mistake? A The fuse blows too easily. B The lamp lights less brightly. C The wires connecting the lamp to the plug overheat if a fault develops. D Too much voltage is supplied to the lamp.

1 marks

Answer: C

This question in 0973/21 Oct/Nov 2024