RE-NEET2026Physics-Kinetic Theory of Gases
RE-NEET 2026 Physics Mean Free Path MCQ Question
Type: MCQ-conceptual-Medium-Class 11
The mean free path of molecules in an ideal gas A is half that of another ideal gas B. The diameter of the spherical molecules of gas A is twice the diameter of the molecules of B. If number densities of the gases A and B are nₐ and n_B, respectively, then the correct option is:
A
nₐ = 2n_B
B
nₐ = 1/4 n_B
C
nₐ = 1/2 n_B
D
nₐ = n_B
Correct Answer
Option A
Detailed Explanation
The mean free path is inversely proportional to the number density and the square of the diameter. Since the diameter of A is twice that of B, and its mean free path is half, nₐ must be twice n_B.
Found an issue with this question?