An experimental sensor plate on a deep-space probe is initially at −150∘C-150^\circ\text{C}−150∘C. It is then exposed to a continuous beam of thermal radiation from a calibration source. The temperature of the plate is recorded at regular intervals as shown in the table below.
| Time in minutes | Temperature in ∘C^\circ\text{C}∘C |
|---|---|
| 0 | -150 |
| 5 | -80 |
| 10 | -30 |
| 15 | 2 |
| 20 | 24 |
| 25 | 39 |
| 30 | 48 |
| 35 | 53 |
| 40 | 55 |
| 45 | 56 |
| 50 | 56 |
Explain, in terms of radiation and energy balance, why the temperature of the sensor plate initially rises and then eventually remains at a constant value of 56∘C56^\circ\text{C}56∘C.
7 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.