Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app

JEE Main 20209 JanuaryEvening Shift

Exam: JEE Main
Year: 2020
Date: 9 January
Shift: Evening Shift
Subject: Physics
Chapter: Kinetic Theory of Gases

JEE Main 2020 · 9 January · Evening Shift · Physics · Kinetic Theory of Gases

Two gases - argon (atomic radius 0.07nm, atomic weight 40 ) and...

Two gases - argon (atomic radius

0.07nm,

atomic weight

40

) and xenon (atomic radius

0.1nm,

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:

Options

A $3.67$
B $1.83$
C $2.3$
D $4.67$

Correct answer

B. $1.83$

Step-by-step solution

Mean free time

= \dfrac{1}{\sqrt{2}n\pi{d}^{2}{v}_{rms}}

\dfrac{{t}_{Ar}}{{t}_{Xe}} = \dfrac{{d}_{Xe}^{2}}{{d}_{Ar}^{2}} \times \sqrt{\dfrac{{m}_{1}}{{m}_{2}}}

= {\left(\dfrac{0.1}{0.07}\right)}^{2} \times \sqrt{\dfrac{40}{140}}

= {\left(\dfrac{10}{7}\right)}^{2} \times \sqrt{\dfrac{2}{7}} = 1.09

closest value is

1 . 83

Practice Kinetic Theory of Gases on Quantrex Academy →

More from Kinetic Theory of Gases

If 2 mole of an ideal monoatomic gas at temperature T , is mixed with 6 mole of another… JEE Main 2026 Given below are two statements: one is labelled as Assertion A and the other is labelled… JEE Main 2026 Given below are two statements: one is labelled as Assertion A and the other is labelled… JEE Main 2026 One gas of n_1 mole of molecules at temperature T_1 , volume V_1 , and pressure P_1 , and… JEE Main 2026 A mixture of carbon dioxide and oxygen has volume 8310 cm ^3 , temperature 300 K… JEE Main 2026 The mean free path of a molecule of diameter 5 × 10^ -10 ~m at the temperature 41^ ∘ C… JEE Main 2026 A gas of certain mass filled in a closed cylinder at a pressure of 3.23 kPa has… JEE Main 2026 Consider two boxes containing ideal gases A and B such that their temperatures, pressures… JEE Main 2026 Full Kinetic Theory of Gases list All JEE Main PYQs