Answer: Can increase or decrease depending on inversion temperature.
- A Usually increases regardless of the gas's initial temperature
- B Usually decreases regardless of the gas's initial temperature
- C Can increase or decrease depending on inversion temperature
- D Stays exactly constant throughout the entire expansion process
Correct answer: C. Can increase or decrease depending on inversion temperature
Explanation: Below the inversion temperature, gas cools on expansion (most gases at room T). Above inversion T, gas heats up. Temperature change depends on inversion temperature.
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.