A student investigates how the type of surface affects the amount of infrared radiation emitted.
They fill a hollow metal cube (a Leslie's cube) with hot water. The four vertical sides of the cube have different surfaces: matt black, matt white, shiny black, and shiny silver.
An infrared detector is used to measure the thermal radiation from each surface, displaying the reading as a temperature.
The table below shows the results of the investigation:
| Type of surface | Temperature in ∘C^{\circ}\text{C}∘C |
|---|---|
| Matt black | 72.4 |
| Matt white | 69.1 |
| Shiny black | 70.3 |
| Shiny silver | 31.2 |
In this investigation, the type of surface is the ________ variable. Choose from: control, dependent, independent.
Based on the values in the table, what is the resolution of the infrared detector?
Describe how this equipment should be used to make a valid comparison of the infrared radiation emitted from each of the four vertical surfaces.
Give one conclusion about the emission of infrared radiation that can be made from these results.
Practise AQA GCSE Physics Black body radiation (physics only) with exam-style questions for Foundation and Higher tier. 9 questions covering Emission and absorption of infrared radiation and Perfect black bodies and radiation, matched to the AQA GCSE Physics (8463) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.