Answer: the work done by the gas.
- A the heat absorbed
- B the work done by the gas
- C the internal energy
- D the change in entropy
Correct answer: B. the work done by the gas
Explanation: Work done by the gas equals the integral of P dV, which is the area under the P-V curve.
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.