question_answer

A Carnot engine, whose efficiency is 40%, takes in heat from a source maintained at a temperature of 500K. It is desired to have an engine of efficiency 60%. Then, the intake temperature for the same exhaust (sink) temperature must be:                  [AIEEE 2012]

A)  efficiency of carnot engine cannot be made larger than 50%

B)  1200 K

C)  750 K  

D)       600 K

Correct Answer: C

Solution :

[c] For 1st case efficiency

for 2nd case