A materials scientist tests four coatings on identical metal plates. Each plate has the same exposed surface area and is maintained at 120 ∘C120\ ^\circ\text{C}120 ∘C.
The table shows the results.
| Coating | Incident radiation absorbed in % | Energy emitted as infrared radiation each second in J |
|---|---|---|
| K | 100 | 14.2 |
| L | 96 | 13.6 |
| M | 72 | 10.3 |
| N | 84 | 11.9 |
Explain which coating could behave as a perfect black body. Use both sets of results in your answer.
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.