A student compared infrared radiation emitted by two identical metal panels mounted inside a drying cabinet. One panel had a matt black surface and the other had a shiny silver surface. The detector was kept at the same distance and angle from each panel. The temperature of each panel stayed constant while its mean detector reading was obtained.
| Surface of panel | Temperature of panel | Mean detector reading in arbitrary units |
|---|---|---|
| matt black | 70 ∘C70\ ^\circ\text{C}70 ∘C | 119 |
| shiny silver | 80 ∘C80\ ^\circ\text{C}80 ∘C | 39.3 |
Explain what conclusion can be drawn about the two surface finishes. Your answer should take the different panel temperatures into account.
106 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.