A frictionless heat engine can be 100% efficient if:
Correct answer: B. The temperature of the sink is 0 K.
- A. The temperature of the sink is 0°C.
- B. The temperature of the sink is 0 K.
- C. The temperature of the source is 0.
- D. The temperature of the sink is equal to the temperature of the source.
Explanation
A frictionless heat engine(Carnot engine) has the following formula for efficiency: Maximum efficiency n = 1 Tc/Th where Th is the temperature of the hot reservoir in KTc is the temperature of the cold reservoir in K.
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About First Law of Thermodynamics
The first law relates heat supplied, work done and the change in internal energy through energy conservation. Problems use sign conventions and apply the law to isothermal, adiabatic, isobaric and isochoric processes. Internal energy is a state function, while heat and work depend on the path followed.
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