WBJEE 2019 Physics Solved Paper

For a gas at temperature T, the internal energy.
U=‌

f

2

µRT
where f = degree of freedom
⇒ Change in energy, ∆U=‌

f

2

µR∆T ...(i)
Also, as we know for any gas heat supplied at constant volume
(∆QV)=µCV∆T=∆U...(ii)
where, CV= molar specific heat at constant volume
From Eqs. (i) and (ii), we get
CV=‌

1

2

fR
For diatomic gas, degree of freedom, f=5
CV=‌

5

2

R