Four model houses, W, X, Y and Z, are identical except that their walls are made of different materials. The walls are all the same thickness.
Each model house is heated to 60 ∘C60\,^\circ\text{C}60∘C and then left to cool in the same room.
Table
| Time (min\text{min}min) | W (∘C^\circ\text{C}∘C) | X (∘C^\circ\text{C}∘C) | Y (∘C^\circ\text{C}∘C) | Z (∘C^\circ\text{C}∘C) |
|---|---|---|---|---|
| 0 | 60 | 60 | 60 | 60 |
| 10 | 52 | 44 | 56 | 48 |
| 20 | 45 | 33 | 52 | 39 |
Which list gives the wall materials in order of thermal conductivity, from lowest to highest?
X, Z, W, Y
Y, W, Z, X
Y, Z, W, X
W, Y, Z, X
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.