Q. Find the ratio of specific heat at constant pressure to the specific heat constant volume for $NH_{3}$
A) $1.33$
B) $1.44$
C) $1.28$
D) $1.67$
Explanation
(c) $\gamma_{poly} = \frac{(4 + f_{vib})}{(3 + f_{vib})}$
$f_{vib} =$ degree of freedom due to vibration $\Rightarrow \gamma_{poly} < \frac{4}{3}$
Or $\gamma_{poly} < 1.33$
Also you can remember that as the atomicity of gas increases the value of $\gamma$-decreases
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.