A student wraps a beaker of hot water in insulation and measures the temperature drop of the water in 10 minutes. The student repeats this for different thicknesses of insulation.
Table
| Thickness of insulation (cm\text{cm}cm) | Temperature drop in 10 minutes (∘C^\circ\text{C}∘C) |
|---|---|
| 0 | 24 |
| 1 | 15 |
| 2 | 10 |
| 3 | 8 |
| 4 | 7 |
Which conclusion is correct?
The temperature drop decreases as the thickness increases, but by less each time
The temperature drop is inversely proportional to the thickness of insulation
The temperature drop decreases by the same amount for each extra centimetre
The temperature drop increases as the thickness of the insulation increases
50 exam-style questions on OCR GCSE Physics 7.2 Power and efficiency, covering 7.2.1 Dissipation of energy, 7.2.2 Energy transfers in domestic devices, 7.2.3 Power ratings of domestic appliances, 7.2.4 Efficiency of energy transfers, 7.2.5 Ways to increase efficiency, 7.2.6 Reducing unwanted energy transfers, and 7.2.7 Thermal conductivity and the cooling of buildings. Each one has a worked solution and a mark scheme showing where the marks go.