JEE Main 2022 · PhysicsMultiple choiceSingle correctEasyCalculation

JEE Main 29 July 2022, Shift 2, Physics Q49

Question 49 of 90 in this shift, Physics question 19 of 30, Section A.

The root mean square speed of smoke particles of mass

5\times10^{-17}

kg in their Brownian motion in air at NTP is approximately. [Given k =

1.38\times10^{-23}\ \mathrm{JK^{-1}}

]

(1)60 $\mathrm{mm\ s^{-1}}$
(2)12 $\mathrm{mm\ s^{-1}}$
(3)15 $\mathrm{mm\ s^{-1}}$ Official answer
(4)36 $\mathrm{mm\ s^{-1}}$

Official answer

Option 3

NTA final key.

Chapter: Kinetic Theory
Topic: Kinetic Theory of Gases
Idea tested: Molecular Speed Types

Same idea in other shifts

Asked 12× in all

6 Apr 2023, Shift 2 · Q39The temperature of an ideal gas is increased from 200 K to 800 K. If r.m.s. speed of gas at 200 K is $v_0$ . Then, r.m.s. speed of the gas…EasySingle correct
11 Apr 2023, Shift 1 · Q43Three vessels of equal volume contain gases at the same temperature and pressure. The first vessel contains neon (monoatomic), the second…EasySingle correct
11 Apr 2023, Shift 2 · Q32The root mean square speed of molecules of nitrogen gas at $27^\circ\mathrm{C}$ is approximately : (Given mass of a nitrogen molecule =…EasySingle correct
12 Apr 2023, Shift 1 · Q39If the r. m. s speed of chlorine molecule is 490 m/s at $27^\circ$ C, the r. m. s speed of argon molecules at the same temperature will be…EasySingle correct
27 Jul 2022, Shift 1 · Q39Same gas is filled in two vessels of the same volume at the same temperature. If the ratio of the number of molecules is 1:4, then A. The…EasyOther
28 Jul 2022, Shift 1 · Q38Given below are two statements : Statement I : The average momentum of a molecule in a sample of an ideal gas depends on temperature.…MediumTwo statements
28 Jul 2022, Shift 2 · Q8A vessel contains 14 g of nitrogen gas at a temperature of $27^\circ$ C. The amount of heat to be transferred to the gas to double the…MediumSingle correct
30 Jul 2022, Shift 2 · Q8If the r.m.s speed of oxygen at room temperature is $\sqrt{56}\ \mathrm{m/s}$ . The r.m.s speed of nitrogen at the same temperature is…EasySingle 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 108 of the 174 JEE Main shifts held from 2017 to 2026.