Pearson Edexcel International GCSE (9–1) · PHYSICS · Chapter
Mains Electricity
58 practice questions
Topics covered
Practice questions
51–58 of 58
Question 51
4 marks · Easy
Answer and see the solution →A student wants to use an electric kettle (rated at 1500 W) on a 230 V mains supply. She checks the plug, which is fitted with a 5 A fuse.
(a)[2 marks]Calculate the current taken by the kettle when it is switched on.
(b)[2 marks]Explain whether a 5 A fuse is suitable for this kettle.
Question 52
4 marks · Easy
Answer and see the solution →A student has a lamp that is fitted with a 3 A fuse and is connected to a 230 V mains supply. The lamp casing is made from metal.
(a)[2 marks]Explain why the lamp must be fitted with an earth wire.
(b)[2 marks]The lamp uses a current of 0.4 A. State whether the 3 A fuse is suitable for this lamp, giving a reason for your answer.
Question 53
4 marks · Easy
Answer and see the solution →A fan heater is rated at 2000 W and is connected to a 230 V mains supply. The heater has a plastic casing, with no earth wire.
(a)[2 marks]Calculate the current used by the heater.
(b)[2 marks]Explain why this appliance does not need an earth wire.
Question 54
4 marks · Easy
Answer and see the solution →A desk lamp is powered by batteries providing direct current (d.c.). A television is powered from the mains (a.c.) supply.
(a)[2 marks]State the difference between the current supplied by batteries and the current supplied by the mains.
(b)[2 marks]Explain why a fuse is used in the plug of the television.
Question 55
4 marks · Normal
Answer and see the solution →A student uses a 230 V electric fan with a power rating of 115 W. The fan's plug contains a fuse, and the outer casing is made of metal.
(a)[2 marks]Calculate the current drawn by the fan to two decimal places.
(b)[2 marks]State the most appropriate size of fuse that should be used in the fan's plug from these options: 3 A, 5 A, 13 A. Explain your answer.
Question 56
5 marks · Normal
Answer and see the solution →A metal-cased toaster and a plastic-cased kettle are shown below.
Appliance features Appliance Casing material Earth wire? Double insulation? Toaster Metal Yes No Kettle Plastic No Yes (a)[3 marks]Explain why the toaster requires an earth wire, but the kettle does not.
(b)[2 marks]State what would happen if the live wire in the toaster became loose and touched the metal case. Explain how the user is protected.
Question 57
4 marks · Normal
Answer and see the solution →A 800 W microwave oven is used in a home where the mains supply is 240 V.
(a)[2 marks]Calculate the current taken by the oven.
(b)[2 marks]The oven is used for 2 minutes. Calculate the total energy transferred by the oven during this time.
Question 58
3 marks · Normal
Answer and see the solution →An electric heater is rated at 2 kW and is connected to a 230 V mains supply. It is used for 30 minutes.
(a)[2 marks]Explain how the heater uses the heating effect of an electric current to warm up a room.
(b)[1 mark]Calculate the total energy transferred by the heater during this time.