Q. The molar specific heat at constant pressure of an ideal gas is $(7/2)R.$ The ratio of specific heat at constant pressure to that at constant volume is
A) $5/7$
B) $9/7$
C) $7/5$
D) $8/7$
Explanation
(c) Molar specific heat at constant pressure $C_{P} = \frac{7}{2}R$
Since, $C_{P} - C_{V} = R \Rightarrow C_{V} = C_{P} - R = \frac{7}{2}R - R = \frac{5}{2}R$
$\therefore\frac{C_{P}}{C_{V}} = \frac{(7/2)R}{(5/2)R} = \frac{7}{5}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.