Q 11-12-020NEETJEE MainEasy
The pressure of a gas is doubled while its temperature is kept constant. Its mean free path
Answer: (B) is halved
$\lambda = \dfrac{kT}{\sqrt{2}\pi d^2p}$. At constant $T$, $\lambda \propto \dfrac{1}{p}$, so doubling the pressure halves the mean free path (the molecules are packed twice as closely).
Solution by Sreeraj P, M.Sc Physics