Physics · PYQ NEET UG 2020

The mean free path for a gas, with molecular diameter d and number density n can be expressed as:

1. \( \frac{1}{\sqrt{2} n \pi d^2} \)
2. \( \frac{1}{\sqrt{2} n^2 \pi d^2} \)
3. \( \frac{1}{\sqrt{2} n^2 \pi^2 d^2} \)
4. \( \frac{1}{\sqrt{2} n \pi d} \)