Answer: remains unchanged.
- A increases
- B decreases
- C remains unchanged
- D becomes zero
Correct answer: C. remains unchanged
Explanation: No work is done and no heat exchanged, so ΔU = 0 and the temperature of an ideal gas stays constant.
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.