Irreversibility versus heat loss: judge the statement Statement: “There is a loss of heat in an irreversible process.” Choose whether the statement is correct or incorrect.
Mechanical Engineering
Thermodynamics
Difficulty: Medium
Choose an option
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AAgree (the statement is correct)
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BDisagree (the statement is incorrect)
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CTrue only for adiabatic processes
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DTrue only for isothermal processes
Answer
Correct Answer: Disagree (the statement is incorrect)
Explanation
Concept/Approach
- Irreversibility is about entropy production due to finite gradients, friction, mixing, shocks, etc.
- Heat loss is neither necessary nor sufficient for irreversibility.
IllustrationAdiabatic throttling (Joule–Thomson) is irreversible with no heat transfer (Q = 0).Conversely, a reversible isothermal process transfers heat but can be reversible.
Final AnswerDisagree — irreversibility is about entropy generation, not necessarily about heat loss.