Thermodynamics Question 2
Question 2 - 2024 (01 Feb Shift 2)
A diatomic gas $(\gamma=1.4)$ does $200 J$ of work when it is expanded isobarically. The heat given to the gas in the process is:
(1) $850 J$
(2) $800 J$
(3) $600 J$
(4) $700 J$
Show Answer
Answer: (4)
Solution:
$\gamma=1+\frac{2}{f}=1.4 \Rightarrow \frac{2}{f}=0.4$
$\Rightarrow f=5$
$W=n R \Delta T=200 J$
$Q=\left(\frac{f+2}{2}\right) nR \Delta T$
$=\frac{7}{2} \times 200=700 J$
