question_answer

A Carnot engine, having an efficiency of\[(-\pi /2,\pi /2)\]1/10 as heat engine, is used as a refrigerator. If the work done on the system is 10 J, the amount of energy absorbed from the reservoir at lower temperature is                                 [AIEEE 2007]

A)  99 J    

B)      90   

C)  1 J      

D)       100 J

Correct Answer: B

Solution :

[b] For Carnot engine using as refrigerator

It is given,

So,