Mean free path of a gas molecule is :

Options

A. inversely proportional to diameter of the molecule
B. inversely proportional to number to number of molecules per unit volume
C. directly proportional to the pressure
D. directly proportional to the square root of the absolute temperature.

Answer

B

Explanation

Mean free path, `lamda=1/(sqrt2pid^2n)`
where
n = Number of molecules per unit volume
d = Diameter of the molecules
As `PV=k_BNT:.n=N/V`
`n = P/(k_BT)`
`:.lamda=(k_BT)/(sqrt2pid^2P)`
where, `k_B` = Boltzmann constant
P = Pressure of gas
T = Temperature of the gas