A Carnot engine, having an efficiency of η=110 as heat engine, is used as a refrigerator. If the work done on the system is 10J, the amount of energy absorbed from the reservoir at lower temperature is

For Carnot engine  Efficiency, η=1-T1T2;110=1-T1T2T1T2=1-110=910                           . . . . (i)For refrigerator∴Q2Q1=T2T1 or Q1+WQ1=T2T1Q1+10Q1=1091+10Q1=109;10Q1=109-1=19Q1=90 J So, 90 J heat is absorbed at lower temperature.