A Carnot engine can achieve 100% thermal efficiency only when the temperature of the__________________?
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Answer: C. Either A. or B
Explanation
Carnot thermal efficiency depends on hot and cold reservoir absolute temperatures. Efficiency reaches one hundred percent if the cold reservoir temperature drops to absolute zero. Alternatively, efficiency reaches one hundred percent if the hot reservoir temperature approaches infinity. Carnot efficiency formula is one minus the ratio of cold temperature to hot temperature. Absolute zero represents the theoretical lower limit of the thermodynamic temperature scale. Real heat engines cannot achieve one hundred percent efficiency due to second law limitations.
Power generation engineers strive to raise hot reservoir temperatures using advanced materials. Understanding Carnot limits helps evaluate the maximum possible performance of heat engines. Environmental constraints usually dictate the ambient temperature of the cold reservoir. Choosing only option A ignores the alternative condition involving infinite hot reservoir temperature. Choosing only option B ignores the alternative condition involving absolute zero cold temperature. Option D is incorrect because the Carnot efficiency formula validates both statements.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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