A manufacturer tests panels for an oven door. Each panel is fitted to an identical test door. The outer surface of each door starts at 20 °C, and its temperature is recorded after 12 minutes. The temperature of the inner surface is kept constant during each test, as shown in the table.
| Panel | Temperature of inner surface in °C | Outer-surface temperature after 12 minutes in °C |
|---|---|---|
| A | 180 | 48 |
| B | 210 | 62 |
| C | 180 | 39 |
| D | 180 | 44 |
Which panel's result should not be used? Explain your answer.
Of the panels whose results can be used, which is the most suitable for the oven door? Use data from the table to explain your answer.
104 exam-style questions on AQA GCSE Physics 1.2 Conservation and dissipation of energy, covering 1.2.1 Energy transfers in a system and 1.2.2 Efficiency. Each one has a worked solution and a mark scheme showing where the marks go.