Answer: Pressure decreases or temperature increases.
- A Pressure increases
- B Temperature decreases
- C Both pressure and temperature decrease
- D Pressure decreases or temperature increases
Correct answer: D. Pressure decreases or temperature increases
Explanation: Mean free path lambda = kT/(sqrt(2) pi d<sup>2</sup> P). Increases when T increases or P decreases.
The Carnot cycle alternates two isothermal steps (heat absorbed at TH, released at TC) with two adiabatic steps (no heat exchange); the enclosed loop area equals the net work output, and η = 1−TC/TH is the maximum possible efficiency between those two temperatures.
Concept context
Laws of thermodynamics, heat engines, entropy, and gas processes.