Section 1: Each problem is worth 5 points

1. The 2nd law of thermodynamics refers to the quality of energy. T F

2. Work can convert to heat completely, but heat cannot convert to work completely. T F

3. It is impossible for reversible heat engine to operate with an efficiency of 100%. T F

4. According to Clausius, heat can transfer naturally from cold bodies to hot bodies. T F

5. The second-law efficiency of a heat engine is always greater than its thermal efficiency. T F

6. Both the first and second laws of thermodynamics must be satisfied in any real system. T F

7. The Carnot COP of a heat pump running between 7°C and 23°C is T F

8. Heat engines with the same 1st law efficiency will always have the same 2nd law efficiency. I F

9. An inventor claims to have created a heat engine that produces 10 kW of power for a 15-kW power

input, while operating between temperature reservoirs at 27°C and 427°C. Is this claim valid?

10. A manufacturer claims that their refrigerator has a COP of 8.5 while running between a conditioned

space at 0°C and ambient air at 23°C. Is this claim valid?