A heat-resistant ceramic tile for a spacecraft is tested by heating it in a test chamber. A detector measures the total intensity of the radiation emitted by the tile, and a spectrometer identifies the wavelength at which the emitted intensity is greatest. The table shows the results.
| Temperature of tile in ∘C^{\circ}\text{C}∘C | Relative total intensity | Wavelength of greatest intensity in μm\mu\text{m}μm |
|---|---|---|
| 600 | 1.0 | 3.3 |
| 900 | 3.3 | 2.5 |
| 1100 | 6.1 | 2.1 |
| 1300 | 10.5 | 1.8 |
The human eye detects wavelengths between 0.40 μm0.40\ \mu\text{m}0.40 μm and 0.70 μm0.70\ \mu\text{m}0.70 μm.
Describe how the relative total intensity and the wavelength of greatest intensity vary as the temperature increases.
Use the data to explain how the proportion of the emitted radiation that is visible light changes as the tile is heated from 600 ∘C600\ ^{\circ}\text{C}600 ∘C to 1300 ∘C1300\ ^{\circ}\text{C}1300 ∘C.
At 600 ∘C600\ ^{\circ}\text{C}600 ∘C, the wavelength of greatest intensity is in the infrared region, but the tile can be seen glowing dull red.
Explain how both observations can be correct.
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.