Q. For a gas if $\gamma = 1.4,$ then atomicity, $C_{P}$ and $C_{V}$ of the gas are respectively
A) Monoatomic, $\frac{5}{2}R,\frac{3}{2}R$
B) Monoatomic, $\frac{7}{2}R,\frac{5}{2}R$
C) Diatomic, $\frac{7}{2}R,\frac{3}{2}R$
D) Triatomic, $\frac{7}{2}R,\frac{5}{2}R$
Explanation
(c) $\gamma = 1 + \frac{2}{f} \Rightarrow 1.4 = 1 + \frac{2}{f} \Rightarrow$ Degree of freedom $f = 5$
$\Rightarrow$ Degree of freedom of diatomic gas is 5 and it’s
$C_{P} = \frac{7}{2}R\ $ and $C_{V} = \frac{5}{2}R$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.