A student compares infrared emission from two hot surfaces using one detector. The table shows the measurements.
| Surface | Temperature in ∘C^\circ\mathrm{C}∘C | Distance from detector in cm\mathrm{cm}cm | Detector reading |
|---|---|---|---|
| matt black | 80 | 5 | 48 |
| shiny silver | 60 | 10 | 12 |
Why do these results not give a valid comparison of the surface finishes?
Both temperature and distance favour a larger reading for matt black.
Both temperature and distance favour a larger reading for shiny silver.
Temperature favours matt black but distance favours shiny silver.
Temperature favours shiny silver but distance favours matt black.
96 exam-style questions on Edexcel GCSE Physics 5.3 Black body radiation, covering 5.3.1 Emission of radiation and temperature, 5.3.2 Radiation balance and constant temperature, and 5.3.3 The temperature of the Earth. Each one has a worked solution and a mark scheme showing where the marks go.