Pearson Edexcel International GCSE (9–1) · PHYSICS · Unit
Electricity
249 practice questions
Topics covered
Practice questions
51–60 of 127 · Normal
Question 51
4 marks · Normal
Answer and see the solution →A manufacturer decides to use a plastic casing for a new electric hand mixer. The mixer is labeled 'double insulated'.
(a)[2 marks]Describe what is meant by double insulation in this context.
(b)[2 marks]Explain why an earth wire is not needed for this appliance.
Question 52
3 marks · Normal
Answer and see the solution →An electric fan develops a fault and starts drawing a current much higher than normal. It is fitted with a fuse in the plug.
(a)[2 marks]Explain how the fuse protects the circuit and user in this situation.
(b)[1 mark]Describe what must be done before the fan can be used again after the fuse blows.
Question 53
3 marks · Normal
Answer and see the solution →An electric kettle operates from a 230 V supply and the current in the kettle is 10 A. Calculate the power of the kettle.
Question 54
3 marks · Normal
Answer and see the solution →Explain why appliances such as kettles and toasters have elements made of materials with high resistance, while the connecting wires in a circuit have low resistance.
Question 55
1 mark · Normal
Answer and check →Which of the following light bulbs transfers the most electrical energy every second?
- A.A 30 W bulb
- B.A 50 W bulb
- C.A 60 W bulb
- D.A 70 W bulb
Question 56
4 marks · Normal
Answer and see the solution →A student is choosing the correct fuse for a 1200 W hairdryer powered by a 240 V mains supply.
(a)[2 marks]Calculate the current drawn by the hairdryer.
(b)[2 marks]Suggest which fuse rating would be suitable: 3 A, 5 A, or 13 A. Explain your answer.
Question 57
2 marks · Normal
Answer and see the solution →State the equation linking power, current, and voltage. Define what each of the symbols stands for.
Question 58
3 marks · Normal
Answer and see the solution →Some light bulbs get hot in normal use. A student wants to design a test to compare the heating effect of two bulbs with different resistances.
(a)[1 mark]State one control variable needed for a fair test.
(b)[1 mark]Suggest a measurement the student could take to compare the heating effect.
(c)[1 mark]Explain the expected result if one bulb has a higher resistance than the other.
Question 59
4 marks · Normal
Answer and see the solution →A table shows data for three different toasters:
Toaster Data Toaster Voltage (V) Current (A) X 230 3.0 Y 230 4.0 Z 230 5.0 (a)[3 marks]Calculate the power rating for each toaster.
(b)[1 mark]State which toaster would get hottest the quickest and explain why.
Question 60
2 marks · Normal
Answer and see the solution →Traditional light bulbs are described as inefficient. Explain what this means, in terms of energy transfer, and why they are being replaced by LEDs.