GCSE Standard Questions: Electricity in the Home
A2.
A student uses a hair dryer. The hair dryer's plug contains a fuse. The diagram below shows the fuse.
(a) Explain how the fuse prevents too large a current in the hair dryer.
A current gives heat energy to the wire when it passes through. If the current is too large for the fuse rating it will melt the wire
and cause a break in the circuit - stopping current flow,
(2 marks)
(b) The hair dryer is rated at 240 V, 1.5 kW. Calculate the current rating in amps of the hair dryer.
Power Rating = Voltage x Current
P = IV
I = P/V
I = 1500 /240 = 6.25 A
(4 marks)
(c) The fuse in the hair dryer blows and the student has to replace it. The following fuses are available:
1A, 3A, 5A and 13A
(i) Which fuse should the student use?
13A
(1 mark)
(ii) Explain your choice.
The lower value fuses would blow as soon as the switch was closed.
(1 mark)
(d) A hair dryer heats up air. Name one other example of electrical heating used in the home.
Any sensible answer:
Electric fire (to radiate heat into a room)
Fan heater to heat the air in the room
Kettle (to heat water)
Immersion heater
(1 mark)
(Total 9 marks)
About this site
