Answer: Phase change.
- A Temperature change
- B Phase change
- C Pressure change
- D Volume change
Correct answer: B. Phase change
Explanation: Latent heat is exchanged during phase change (e.g., melting or boiling) with NO temperature change.
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.