The Carnot efficiency of a heat engine operating between 600K (hot) and 300K (cold) is: A 25% B 50% C 75% D 100% ✓ Correct Answer: Option B η_Carnot = 1 − T_cold/T_hot = 1 − 300/600 = 0.5 = 50%. Practice FE Exam Prep Quizzes → Browse All Questions Study Flashcards