Pearson Edexcel International GCSE (9–1) · PHYSICS · Section
Electrical power
16 practice questions
Practice questions
1–8 of 8 · Normal
Question 1
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 2
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 3
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 4
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 5
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 6
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 7
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 8
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.