Question

What would be the efficiency of a Carnot engine operating with boiling water as one reservoir and a freezing mixture of ice and water as the other reservoir?

• A. $27$ %
• B. $77$ %
• C. $20$ %
• D. $67$ %

Answer 1

The correct option is A $27$ %

The boiling point of water is ${100}^{o}C$ and freezing point of water is $0^{o}C$

Thus, $T_h=100+273=373K$ and $T_c=0+273=273K$

The efficiency of a Carnot engine , $\eta =(1-\frac{T_c}{T_h})\times 100=[1-373/273]\times 100=26.8\sim 27$ %