For a thermodynamic process to achieve reversibility, the temperature variance between the hot body and the working substance ought to be___________________?
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Answer: A. zero
Explanation
Reversibility demands that systems remain infinitesimally close to thermodynamic equilibrium throughout every single operational stage. Finite temperature differences drive spontaneous heat transfer, which introduces irreversibility and generates unwanted entropy. Achieving complete reversibility therefore requires the driving temperature gradient to approach zero across the system boundary. Thermodynamic reversibility is an idealized concept used to establish the maximum possible performance limits. Second law of thermodynamics states that real world processes always generate entropy and feature finite gradients. Heat transfer across a temperature difference is inherently irreversible due to the spontaneous dispersion of thermal energy.
Carnot engines utilize isothermal heat transfer steps to approach the ideal limit of reversible operations. Engineers strive to minimize temperature differences in heat exchangers to reduce thermodynamic losses and inefficiency. Understanding reversibility helps evaluate how closely real thermal machinery approaches theoretical maximum efficiency boundaries. Option B suggests a minimum variance, but any finite difference still produces irreversible entropy generation. Option C would maximize irreversibility and thermal degradation rather than achieving any theoretical reversibility goals. Option D implies infinite resistance, which prevents any meaningful heat transfer from occurring within the device.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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