Answer: Polytropic.
- A Isothermal
- B Adiabatic
- C Polytropic
- D Isobaric
Correct answer: C. Polytropic
Explanation: Polytropic process: PV<sup>n</sup> = constant. Special cases: isothermal (n=1), adiabatic (n=gamma), isobaric (n=0), isochoric (n=infinity).
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.