Answer: Temperature.
- A Pressure
- B Volume
- C Temperature
- D All three
Correct answer: C. Temperature
Explanation: For an ideal gas, internal energy depends only on temperature (kinetic energy of molecules).
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.