GCSE Questions - Electromagnetic Spectrum
Q11. (a) The diagram shows the position of three types of wave in the electromagnetic spectrum.
![](graphics/spectrum11.png)
(i) Which letter represents infrared in the electromagnetic spectrum?
B ![](../../../graphics/symbols/nuclides/ticksmall.png)
[1 mark]
(ii) Which of the following is infrared used for? Tick one box.
Electrical heating |
![](../../../graphics/symbols/nuclides/ticksmall.png) |
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.
![](graphics/irphoto.png)
(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 ![](../../../graphics/symbols/nuclides/ticksmall.png)
[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. ![](../../../graphics/symbols/nuclides/ticksmall.png)
[1 mark]
(c) Jimmy investigated how the type of surface affects the amount of infrared the surface radiates. This diagram shows the equipment used.
![](graphics/experiment10.png)
(i) What kind of variable in this investigation is 'type of surface'?
The independant variable. ![](../../../graphics/symbols/nuclides/ticksmall.png)
[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 ![](../../../graphics/symbols/nuclides/ticksmall.png)
point the IR detector at each side and take a reading ![](../../../graphics/symbols/nuclides/ticksmall.png)
keep the detector the same distance from each surface ![](../../../graphics/symbols/nuclides/ticksmall.png)
[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 ![](../../../graphics/symbols/nuclides/ticksmall.png)
[1 mark]
This bar chart shows two of the results:
![](graphics/barchartANS.png)
(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)