JEE Main 2020 · PhysicsMultiple choiceSingle correctMediumMulti-step

JEE Main 9 January 2020, Shift 2, Physics Q10

Question 10 of 75 in this shift, Physics question 10 of 25, Section A.

Two gases - argon (atomic radius 0.07 nm, atomic weight 40) and xenon (atomic radius 0.1 nm, atomic weight 140) have the same number density and are at the same temperature. The ratio of their respective mean free times is closest to :

(1)3.67Official answer
(2)4.67
(3)2.3
(4)1.83

Official answer

Option 1

NTA final key (Jan 2020).

Chapter: Kinetic Theory
Topic: Kinetic Theory of Gases
Idea tested: Relaxation Time

Same idea in other shifts

Asked 3× in all

8 Jan 2020, Shift 1 · Q9The plot that depicts the behavior of the mean free time $\tau$ (time between two successive collisions) for the molecules of an ideal…MediumDiagram basedHas a figure
6 Sep 2020, Shift 2 · Q9In a dilute gas at pressure P and temperature T, the mean time between successive collisions of a molecule varies with T as :MediumSingle correct

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 42 of the 174 JEE Main shifts held from 2017 to 2026.