Answer
63 %
Explanation:
It is given that the reservoirs is at the temperature of 627°C and 27°C
So lower temperature that is[tex]T_L[/tex] = 60°C=273+60=333 K
And the higher temperature that is [tex]T_H[/tex] = 627°C =273+627=900 K
We know that the thermal efficiency of thermal reservoir = 1-[tex]\frac{T_L}{T_H}[/tex] = [tex]1-\frac{333}{900}[/tex] = 0.63 =63 %
So the efficiency of the reservoir is 63%
