The diagram shows four slabs of different materials with equal thickness, placed side by side. Heat flows from left to right and the steady-state temperatures of the interfaces are given. Rank the materials according to their thermal conductivities, smallest to largest.

Question

Quizplus · Accepted Answer

From the diagram, we can see that the temperature difference between the first two materials (1 and 2) is smaller than the temperature difference between the second two materials (3 and 4). This means that heat transfers more easily between materials 1 and 2 than it does between materials 3 and 4. Therefore, materials 1 and 2 have lower thermal conductivities than materials 3 and 4.

We also know that material 1 has the lowest thermal conductivity, since it has the lowest interface temperature. Similarly, material 4 has the highest thermal conductivity, since it has the highest interface temperature.

Therefore, the correct ranking of materials from smallest to largest thermal conductivity is 3, 4, 2, 1, or choice D.

The Diagram Shows Four Slabs of Different Materials with Equal