Engineering Board Exam Reviewer · Thermodynamics · medium
An actual heat engine has a thermal efficiency of 30%, while a Carnot engine between the same reservoirs has an efficiency of 50%. What is the second-law efficiency of the actual engine?
- 20%
- 60%
- 80%
- 15%
Answer
B. 60%
Solution
II = ηactual/ηrev = 0.30/0.50 = 60%.
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