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.
4 exam-style questions on AQA GCSE Physics 6.3 Black body radiation, covering 6.3.1 Emission and absorption of infrared radiation and 6.3.2 Perfect black bodies and radiation. Each one has a worked solution and a mark scheme showing where the marks go.