Physics (AS & A Level) · May / June 2025 · Paper 13 · Question 4

A sample of material has cross-sectional area A and length L. The temperatures at the two sides of the sample are T₁ and T₂. Thermal energy Q is transferred through the sample in time t. These quantities are related by \frac{Q}{t} = \frac{k \times A \times (T_1 - T_2)}{L} where k is a constant. What are the SI base units of k?

1. Akg m s⁻³ °C⁻¹
2. Bkg m s⁻³ K⁻¹
3. Ckg m s⁻¹ °C⁻¹
4. Dkg m s⁻¹ K⁻¹

As printed in the paper