Air standards cycles Questionbank

Air standards cycles

For a Carnot engine operating between two thermal reservoirs at temperatures \( T_H = 600 \text{K} \) and \( T_C = 300 \text{K} \), what is the maximum possible efficiency?

  • 0.25
  • 0.5
  • 0.75
  • 1.0

Explanation:

  • The maximum possible efficiency for any heat engine is given by the Carnot efficiency: \( \eta = 1 – \frac{T_C}{T_H} \), where temperatures are in Kelvin.
  • Substituting the values: \( \eta = 1 – \frac{300}{600} = 1 – 0.5 = 0.5 \) or 50%.
  • 1.0 (or 100%) represents an ideal, impossible perpetual motion machine of the second kind, violating the Second Law of Thermodynamics.
Air standards cycles Questionbank