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Question 31032
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Kinetic Theory and Thermodynamics: Carnot Engine MCQ

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Carnot EngineHardQuestion 31032

Question

Efficiency of a Carnot engine can be 100% only if cold reservoir temperature T₂ is:
  1. A
    0°C
  2. B
    −273°C (absolute zero)
    Correct
  3. C
    Same as T₁
  4. D
    Very high

Correct answer

−273°C (absolute zero)

Explanation

η = 1 − T₂/T₁. η = 1 only when T₂ = 0 K. Absolute zero is unattainable by third law, so 100% efficiency is impossible.

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