Pearson Edexcel International GCSE (9–1) · PHYSICS · Chapter
Units (Electricity)
87 practice questions
Topics covered
Practice questions
81–87 of 87
Question 81
4 marks · Easy
Answer and see the solution →The information panel on an electric toaster says: 'Power: 800 W, Voltage: 200 V'. The plug has a fuse fitted.
(a)[2 marks]Calculate the current drawn by the toaster when it is working.
(b)[2 marks]Suggest which fuse should be used in the plug if the available sizes are 3 A and 5 A. Explain your answer.
Question 82
4 marks · Easy
Answer and see the solution →The diagram shows a simple circuit with a lamp powered by a battery.
Circuit containing a battery (12 V), a lamp, and an ammeter in series. The ammeter reads 0.5 A. (a)[2 marks]Calculate the energy transferred by the lamp in 60 seconds.
(b)[2 marks]State the amount of electric charge that passes through the lamp in 60 seconds.
Question 83
4 marks · Easy
Answer and see the solution →A brand-new electric iron is labelled '230 V, 1200 W'. It has a metal case and is connected to the mains by a three-core cable.
(a)[2 marks]State the purpose of the earth wire in this appliance.
(b)[2 marks]If the iron is switched on for 3 minutes, calculate the total energy transferred to it.
Question 84
5 marks · Normal
Answer and see the solution →A student uses a 12 V, 18 W lamp. During an experiment, a total charge of 90 C passes through it.
(a)[2 marks]Calculate the current in the lamp.
(b)[2 marks]Calculate the time during which this charge flowed.
(c)[1 mark]State the units for electric charge and current, and explain their relationship.
Question 85
4 marks · Normal
Answer and see the solution →The table shows data collected by a student measuring current through two different components, X and Y, as the voltage increases. Both are measured at room temperature.
Current and voltage for components X and Y Voltage (V) Current in X (A) Current in Y (A) 0 0.00 0.00 0.5 0.08 0.15 1.0 0.16 0.30 1.5 0.24 0.37 2.0 0.32 0.39 (a)[2 marks]Using the table, calculate the resistance of component X at 1.5 V.
(b)[2 marks]State the unit for resistance and suggest, giving a reason, which component is likely to be a filament bulb.
Question 86
5 marks · Normal
Answer and see the solution →A hairdryer plug shows the label: 220 V, 660 W. The hairdryer uses a two-core cable but does not have an earth wire.
(a)[2 marks]Explain what is meant by 'double insulation' and why this hairdryer does not require an earth wire.
(b)[1 mark]Calculate the current drawn by the hairdryer.
(c)[1 mark]A fuse is chosen by dividing the power by the voltage, then rounding up to the next available size. State which value of fuse (from 3 A, 5 A, 13 A) is most suitable for this hairdryer.
(d)[1 mark]Give two reasons why using a fuse is important for safety in this appliance.
Question 87
5 marks · Normal
Answer and see the solution →A heater is rated at 230 V, 2.3 kW. During a cold evening, it is left switched on for 15 minutes.
(a)[2 marks]Calculate the resistance of the heater.
(b)[2 marks]Calculate the energy transferred by the heater in 15 minutes.
(c)[1 mark]State the correct SI unit for 'energy transferred'. Explain why the heater becomes hot when current flows through it.