JEE Exam > JEE Questions > A heat engine has an efficiency η. Temperatu...
Start Learning for Free
A heat engine has an efficiency η. Temperatures of source and sink are each decreased by 100 K. Then, the efficiency of the engine.
- a)Increases
- b)Decreases
- c)Remains constant
- d)Becomes 1
Correct answer is option 'A'. Can you explain this answer?
Most Upvoted Answer
A heat engine has an efficiency η. Temperatures of source and sink ar...
where T1 and T2 are the temperatures of a source and sink respectively.
When T1 and T2 both are decreased by 100 K each, (T1 - T2) stays constant. T1 decreases.
∴ η increases.
Free Test
FREE
| Start Free Test |
Community Answer
A heat engine has an efficiency η. Temperatures of source and sink ar...
The Efficiency of a Heat Engine
A heat engine is a device that converts thermal energy into mechanical work. The efficiency of a heat engine is defined as the ratio of the useful work output to the heat energy input. It is denoted by the symbol η.
Efficiency = (Useful work output) / (Heat energy input)
Effect of Decreasing Temperatures
When the temperatures of the source and sink in a heat engine are decreased, it has an impact on the efficiency of the engine. Let's explore the effect:
1. Source Temperature Decreased:
When the temperature of the source is decreased, the difference in temperature between the source and the sink decreases. This reduces the maximum possible efficiency of the engine according to the Carnot efficiency formula:
Carnot Efficiency = 1 - (Tc/Th)
where Tc is the temperature of the sink and Th is the temperature of the source. As the temperature of the source decreases, the Carnot efficiency decreases.
2. Sink Temperature Decreased:
When the temperature of the sink is decreased, the heat rejected by the engine decreases. This reduces the amount of heat energy input to the engine. As a result, the efficiency of the engine increases because there is less wasted heat energy.
Overall Effect on Efficiency
When both the source and sink temperatures are decreased by the same amount, the decrease in the Carnot efficiency due to the source temperature decrease is offset by the decrease in wasted heat energy due to the sink temperature decrease.
Therefore, the overall effect of decreasing both temperatures is an increase in the efficiency of the engine. This can be seen by considering the formula for efficiency:
Efficiency = (Useful work output) / (Heat energy input)
As the heat energy input decreases due to the decreased sink temperature, and the useful work output remains the same, the efficiency increases.
Conclusion
In summary, when the temperatures of the source and sink in a heat engine are decreased by the same amount, the efficiency of the engine increases. This is because the decrease in wasted heat energy due to the decreased sink temperature outweighs the decrease in Carnot efficiency due to the decreased source temperature.
A heat engine is a device that converts thermal energy into mechanical work. The efficiency of a heat engine is defined as the ratio of the useful work output to the heat energy input. It is denoted by the symbol η.
Efficiency = (Useful work output) / (Heat energy input)
Effect of Decreasing Temperatures
When the temperatures of the source and sink in a heat engine are decreased, it has an impact on the efficiency of the engine. Let's explore the effect:
1. Source Temperature Decreased:
When the temperature of the source is decreased, the difference in temperature between the source and the sink decreases. This reduces the maximum possible efficiency of the engine according to the Carnot efficiency formula:
Carnot Efficiency = 1 - (Tc/Th)
where Tc is the temperature of the sink and Th is the temperature of the source. As the temperature of the source decreases, the Carnot efficiency decreases.
2. Sink Temperature Decreased:
When the temperature of the sink is decreased, the heat rejected by the engine decreases. This reduces the amount of heat energy input to the engine. As a result, the efficiency of the engine increases because there is less wasted heat energy.
Overall Effect on Efficiency
When both the source and sink temperatures are decreased by the same amount, the decrease in the Carnot efficiency due to the source temperature decrease is offset by the decrease in wasted heat energy due to the sink temperature decrease.
Therefore, the overall effect of decreasing both temperatures is an increase in the efficiency of the engine. This can be seen by considering the formula for efficiency:
Efficiency = (Useful work output) / (Heat energy input)
As the heat energy input decreases due to the decreased sink temperature, and the useful work output remains the same, the efficiency increases.
Conclusion
In summary, when the temperatures of the source and sink in a heat engine are decreased by the same amount, the efficiency of the engine increases. This is because the decrease in wasted heat energy due to the decreased sink temperature outweighs the decrease in Carnot efficiency due to the decreased source temperature.
|
Explore Courses for JEE exam
|
|
Top Courses for JEEView all
A heat engine has an efficiency η. Temperatures of source and sink are each decreased by 100 K. Then, the efficiency of the engine.a)Increasesb)Decreasesc)Remains constantd)Becomes 1Correct answer is option 'A'. Can you explain this answer?
Question Description
A heat engine has an efficiency η. Temperatures of source and sink are each decreased by 100 K. Then, the efficiency of the engine.a)Increasesb)Decreasesc)Remains constantd)Becomes 1Correct answer is option 'A'. Can you explain this answer? for JEE 2025 is part of JEE preparation. The Question and answers have been prepared according to the JEE exam syllabus. Information about A heat engine has an efficiency η. Temperatures of source and sink are each decreased by 100 K. Then, the efficiency of the engine.a)Increasesb)Decreasesc)Remains constantd)Becomes 1Correct answer is option 'A'. Can you explain this answer? covers all topics & solutions for JEE 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A heat engine has an efficiency η. Temperatures of source and sink are each decreased by 100 K. Then, the efficiency of the engine.a)Increasesb)Decreasesc)Remains constantd)Becomes 1Correct answer is option 'A'. Can you explain this answer?.
A heat engine has an efficiency η. Temperatures of source and sink are each decreased by 100 K. Then, the efficiency of the engine.a)Increasesb)Decreasesc)Remains constantd)Becomes 1Correct answer is option 'A'. Can you explain this answer? for JEE 2025 is part of JEE preparation. The Question and answers have been prepared according to the JEE exam syllabus. Information about A heat engine has an efficiency η. Temperatures of source and sink are each decreased by 100 K. Then, the efficiency of the engine.a)Increasesb)Decreasesc)Remains constantd)Becomes 1Correct answer is option 'A'. Can you explain this answer? covers all topics & solutions for JEE 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A heat engine has an efficiency η. Temperatures of source and sink are each decreased by 100 K. Then, the efficiency of the engine.a)Increasesb)Decreasesc)Remains constantd)Becomes 1Correct answer is option 'A'. Can you explain this answer?.
Solutions for A heat engine has an efficiency η. Temperatures of source and sink are each decreased by 100 K. Then, the efficiency of the engine.a)Increasesb)Decreasesc)Remains constantd)Becomes 1Correct answer is option 'A'. Can you explain this answer? in English & in Hindi are available as part of our courses for JEE.
Download more important topics, notes, lectures and mock test series for JEE Exam by signing up for free.
Here you can find the meaning of A heat engine has an efficiency η. Temperatures of source and sink are each decreased by 100 K. Then, the efficiency of the engine.a)Increasesb)Decreasesc)Remains constantd)Becomes 1Correct answer is option 'A'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
A heat engine has an efficiency η. Temperatures of source and sink are each decreased by 100 K. Then, the efficiency of the engine.a)Increasesb)Decreasesc)Remains constantd)Becomes 1Correct answer is option 'A'. Can you explain this answer?, a detailed solution for A heat engine has an efficiency η. Temperatures of source and sink are each decreased by 100 K. Then, the efficiency of the engine.a)Increasesb)Decreasesc)Remains constantd)Becomes 1Correct answer is option 'A'. Can you explain this answer? has been provided alongside types of A heat engine has an efficiency η. Temperatures of source and sink are each decreased by 100 K. Then, the efficiency of the engine.a)Increasesb)Decreasesc)Remains constantd)Becomes 1Correct answer is option 'A'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice A heat engine has an efficiency η. Temperatures of source and sink are each decreased by 100 K. Then, the efficiency of the engine.a)Increasesb)Decreasesc)Remains constantd)Becomes 1Correct answer is option 'A'. Can you explain this answer? tests, examples and also practice JEE tests.
|
|
Explore Courses for JEE exam
|
|
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
|
© EduRev
|
Education Revolution
|
|
Signup to see your scores
go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup