Question

If the sink temperature is decreased and the source temperature is held constant, then the efficiency of a Carnot engine can be:

• A. increased
• B. decreased
• C. remain constant
• D. None of these

Answer 1

The correct option is A increased

The efficiency of a Carnot engine is given by $\eta =1-\frac{T_{sink}}{T_{source}}$.
If $T_{sink}$ is decreased and $T_{source}$ is kept constant we notice that $\eta$ increases.

Hence, the correct option is $\text{A}$