CAPE Physics Unit 1 · 2015 · Paper 1 · Question Q33

The thermal conductivity, k, of a material in the form of a uniform cylinder is to be determined from the rate of linear heat flow, P, its cross-sectional area, A, and the temperature gradient, G (where G = \frac{\Delta \theta}{\Delta x}). Which of the following equations is correct?

1. (A)k = \frac{G}{PA}
2. (B)k = \frac{P}{AG}
3. (C)k = \frac{GA}{P}
4. (D)k = \frac{PA}{G}