The ratio of rotational kinetic energy to the total kinetic energy of a diatomic molecule is :

Options

A. `3/5`
B. `2/5`
C. `2/3`
D. `5/2`

Answer

B

Explanation

For diatomic molecule , number of rotational degrees of freedom = 2.
Rotational K.E =`2 xx(1/2kT)`
= kT
Total number of degrees of freedom = 5
`:.` Total K.E `=5(1/2kT) =5/2kT`
`:.("RotationalK.E")/("Total K.E")=(kT)/(5//2kT) =2/5`