Pearson Edexcel International GCSE (9–1) · PHYSICS · Section
Alternating current and direct current
17 practice questions
Practice questions
11–17 of 17
Question 11
4 marks · Normal
Answer and see the solution →A lamp is connected to a 12 V battery and draws a current of 2.5 A. It is switched on for 4 minutes.
(a)[1 mark]Calculate the power of the lamp.
(b)[3 marks]Calculate the total energy transferred by the lamp in this time. Give your answer in joules.
Question 12
2 marks · Normal
Answer and see the solution →State the main difference between alternating current (a.c.) and direct current (d.c.). Give one example of each.
Question 13
1 mark · Normal
Answer and check →Which device provides direct current (d.c.) only?
- A.Car battery
- B.Household mains supply
- C.Wind turbine generator
- D.Transformer
Question 14
3 marks · Normal
Answer and see the solution →A coffee machine is labelled 900 W, 230 V. Calculate:
(a)[3 marks]The current it draws from the mains when operating normally. Give your answer to 2 decimal places.
Question 15
4 marks · Normal
Answer and see the solution →A mobile phone charger is rated at 5 V and is connected to a current of 0.6 A.
(a)[1 mark]Calculate the power used by the charger.
(b)[3 marks]If the charger is used for 3 hours, calculate the total energy transferred in kilojoules (kJ).
Question 16
3 marks · Normal
Answer and see the solution →The voltage of two electricity supplies, X and Y, was measured over time. The results are given below:
Voltage measurements for supplies X and Y over time. Time (s) Supply X (V) Supply Y (V) 0 0 3 1 3 3 2 0 3 3 -3 3 4 0 3 On the axes below, plot the voltages of X and Y against time (from 0 to 4 s).
Question 17
3 marks · Normal
Answer and see the solution →A 150 W computer monitor runs on a 19 V supply. Calculate the current in the monitor and the total energy transferred if it is used for 2 hours.
(a)[2 marks]Calculate the current. Give your answer to 2 decimal places.
(b)[1 mark]Calculate the energy transferred in kilojoules (kJ).