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JEE Main202131 Aug 2021Morning ShiftPhysicsThermodynamicsActual

A reversible engine has an efficiency of 1 4 . If the temperature of the sink is reduced by 58 ° C , its efficiency becomes double. Calculate the temperature of the sink:

Options

  1. A180 . 4 ° C
  2. B382 ° C
  3. C174   K
  4. D280 ° C

Correct answer

C. 174   K

Step-by-step solution

η = 1 - T L T H 1 4 = 1 - T L T H T L T H = 3 4 2 η = 1 2 = 1 - T L - 58 T H T L - 58 T H = 1 2 T L T L - 58 = 3 / 4 1 / 2 2   T L = 3   T L - 174 T L = 174   K This question is bonus as the value given by NTA in option was in degree celsius.

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