A carnot engine having an efficiency of eta=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 _____

A carnot engine having an efficiency of eta=1/10 as heat engine is use

1.	A carnot engine having an efficiency of eta=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 _____
Answer» <html><body><p>100 <a href="https://interviewquestions.tuteehub.com/tag/j-520843" style="font-weight:bold;" target="_blank" title="Click to know more about J">J</a><br/>99 J<br/>90 J<br/>1 J</p>Solution :Coefficient performance of <a href="https://interviewquestions.tuteehub.com/tag/refrigeration-1181948" style="font-weight:bold;" target="_blank" title="Click to know more about REFRIGERATION">REFRIGERATION</a>, <br/> `alpha Q_2/W=Q_2/(Q_1-Q_2)` <br/> `therefore Q_2/W=(Q_2/Q_1)/(1-Q_2/Q_1)` <br/> `therefore Q_2/W=(1-eta)/eta[eta=1-Q_2/Q_1 <a href="https://interviewquestions.tuteehub.com/tag/rarr-1175461" style="font-weight:bold;" target="_blank" title="Click to know more about RARR">RARR</a> Q_2/Q_1=1=eta]` <br/> `therefore Q_2=Wxx(1-eta)/eta` <br/> `therefore Q_2=10xx(1-1/10)/(1/10)` <br/> `therefore Q_2`=90 J</body></html>