GCSE Questions - Electromagnetic Spectrum
Q11. (a) The diagram shows the position of three types of wave in the electromagnetic spectrum.
(i) Which letter represents infrared in the electromagnetic spectrum?
B 
[1 mark]
(ii) Which of the following is infrared used for? Tick one box.
| Electrical heating |
|
| Energy efficient lamps |
|
| Satellite communications |
|
| Sun tanning |
|
[1 mark]
(b) An infrared camera produces a colour image. Different colours show box different temperatures. People emit infrared radiation. The photo below shows how the colour of the image of a person on an infrared camera depends on the person's body temperature.
(i) What colour would an image produced by an infrared camera of a person with a body temperature of 37 °C be mainly composed of?
Orange
[1 mark]
(ii) Rescue workers use infrared cameras to search for people trapped under rubble after an earthquake.
How does the image of a trapped person change if the person's body temperature drops from 37 °C to 33 °C?
It becomes redder.
[1 mark]
(c) Jimmy investigated how the type of surface affects the amount of infrared the surface radiates. This diagram shows the equipment used.
(i) What kind of variable in this investigation is 'type of surface'?
The independant variable.
[1 mark]
(ii) Describe how the equipment shown above would be used to compare the infrared radiation emitted from the vertical surfaces of the cube.
pour (hot) water into the (hollow metal) cube
point the IR detector at each side and take a reading
keep the detector the same distance from each surface
[3 marks]
The table shows the results:
Type of surface |
Temperature in °C |
Matt black |
68.0 |
Matt white |
65.5 |
Shiny black |
66.3 |
Shiny silver |
28.0 |
(iii) What is the resolution of the infrared detector?
0.1 oC
[1 mark]
This bar chart shows two of the results:
(iv) Complete the bar chart to show all of the results.
[3 marks]
(v) Give one conclusion that can be made from the results.
Any one from:
(matt) black is the best (or a good) emitter
shiny silver is the worst (or a poor) emitter
matt white and shiny black are (almost) the same at emitting
[1 mark]
(Total 13 marks)
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