Question

The temperature-entropy diagram of a reversible engine cycle is given in the fig, Its efficiency?

• A. $\frac{1}{2}$
• B. $\frac{1}{4}$
• C. $\frac{1}{3}$
• D. $\frac{2}{3}$

Answer 1

Answer: (C)

$\frac{1}{3}$

$\text{Solution}:$

$Q_1=T_0{S}_0+\frac{1}{2}{T}_0{S}_0=\frac{3}{2}{T}_0{S}_0$

$Q_2=T_0(2S_0-S_0)=T_0{S}_0$ and

$Q_3=0$

$\eta =1-\frac{Q_2}{Q_1}=1-\frac{T_0{S}_0}{\frac{3}{2}{T}_0{S}_0}=\frac{1}{3}$

$\text{Hence C is the correct option}$