The process by which a gas passes through a small hole into vacuum is called effusion. The rate of change of pressure(p) of a gas at constant temperature due to effusion of gas from a vessel of constant volume can be related to rate of change of number of molecules by the expression:
`(dp)/(dt)=(kT)/V((dN)/(dt))`
where rate of change of number of molecules
`Rightarrow -((dN)/(dt))=(pA_(0))/(2pimkT)^(1//2)`
where k=Boltzmann constant
`N_(A)` = Avogadro's number
T= Temperature (in K)
V= volume of vessel
N=Number of molecules
`A_(0)` = Area of aperture
m=Mass of single molecule
`gamma=V/A_(0)sqrt((2pim)/(kT)`
In 1 m long tube at one end He is introduced while from other end `SO_(2)` is introduced under identical conditions Gas will first meet from He and at a distance:

Options

A. `1/2` m
B. `1/5` m
C. `3/5` m
D. `4/5` m

Answer

d