Pearson Edexcel International GCSE (9–1) · PHYSICS · Chapter
Units (Electricity)
87 practice questions
Topics covered
Practice questions
41–43 of 43 · Normal
Question 41
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 42
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 43
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.