Question

In a Carnot heat engine, the temperature of source and sink are $500\text{K}$ and $375\text{K}$ respectively. The efficiency of engine is

• A. $75\%$
• B. $25\%$
• C. $33\%$
• D. $-33\%$

Answer 1

The correct option is B $25\%$

Temperature of source, $T_1=500\text{K}$
Temperature of sink, $T_2=375\text{K}$
Efficiency of Carnot heat engine,
$\eta =1-\frac{T_2}{T_1}$
$\Rightarrow \eta =1-\frac{375}{500}$
$\therefore \eta =0.25$ or $25\%$