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Grade 11Thermal Physics

Under what conditions would an ideal heat engine be 100% efficient?

Profile image of Simran Bhatia
11 Years agoGrade 11
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3 Answers

Profile image of Aditi Chauhan
11 Years ago
The efficiency (η) of a heat engine is defined as,
η = 1 – T2/T1
Here T1 is the temperature of source and T2 is the temperature of sink.
The efficiency of an engine depends upon the temperatures between which it operates and is independent of the nature of working substance. The efficiency of an engine will be 100 % (η = 1) if the temperature of sink (T2) is zero. Since absolute zero is not attainable, even an ideal engine cannot have efficiency as 1. This signifies that, it is impossible to extract heat from a single body and convert the whole of it into work
Profile image of Adarsh
11 Years ago
Wh
Profile image of Adarsh
11 Years ago
When the difference  between the temperature of the source and the sink is very large the heat engine’s efficiency will also be more.
If there is no loss of energy in any form and temperature of the sink is zero, then the heat engine will be 100% efficient.
Practically, it is impossible as there is always some energy is lost and the temperature of the sink cannot be zero.
 
Hope you understand the solution.