ISRO Mechanical & Aerospace 2013 - Question 24

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Efficiency of Carnot engine is given as 80%. If the cycle direction is reversed, what will be the value of COP of reversed Carnot cycle

  • A. 1.25
  • B. 0.5
  • C. 0.25
  • D. none of the above

Answer: C. 0.25

Explanation: Efficiency n = (Th-Tl)/Th = 0.8. Tl/Th = 0.2. COP of Refrigerator = Tl / (Th-Tl) = (Tl/Th) / (1 - Tl/Th) = 0.2 / 0.8 = 0.25.

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