PYQ Vault
EbooksTutor

Kinetic Theory

JEE Mains Physics. Try each one first, then open its answer.

Top 10 JEE Mains PYQs to practise first

The questions and kinds of question asked most often come first. Each one says how often and in which papers.

  1. Question 1

    This type asked 9 times: 2021 Paper 18, 2021 Paper 21, 11 Apr 2023, 12 Apr 2023, 30 Jan 2024, 1 Feb 2024, 6 Apr 2024, 28 Jan 2025, 21 Jan 2026 S2. This one: 21 Jan 2026 S2 See all 9 of this type

    5
    The r.m.s speed of oxygen molecules at 47∘C47^{\circ}C is equal to that of the hydrogen molecules kept at ____\_\_\_\_  ∘C\ ^{\circ}C. (Mass of oxygen molecule/mass of hydrogen molecule=32/2)

    Tap an option to check your answer.

  2. Question 2

    This type asked 9 times: 2021 Paper 7, 2021 Paper 8, 25 Jun 2022, 26 Jul 2022, 24 Jan 2023, 25 Jan 2023, 22 Jan 2025, 2 Apr 2025, 7 Apr 2025. This one: 7 Apr 2025 See all 9 of this type

    13
    Match the List-I with List-II
    List-IList-II
    A. Triatomic rigid gasI. CPCV=53\frac{C_{P}}{C_{V}} = \frac{5}{3}
    B. Diatomic non-rigid gasII. CPCV=75\frac{C_{P}}{C_{V}} = \frac{7}{5}
    C. Monoatomic gasIII. CPCV=43\frac{C_{P}}{C_{V}} = \frac{4}{3}
    D. Diatomic rigid gasIV. CPCV=97\frac{C_{P}}{C_{V}} = \frac{9}{7}
    Choose the correct answer from the options given below :

    Tap an option to check your answer.

  3. Question 3

    This type asked 6 times: 28 Jun 2022, 10 Apr 2023, 27 Jan 2024, 31 Jan 2024, 6 Apr 2024, 2 Apr 2025. This one: 2 Apr 2025 See all 6 of this type

    97
    The internal energy of air i n 4 m×4 m×3 m4\text{ }m \times 4\text{ }m \times 3\text{ }m sized room at 1 atmospheric pressure will be ____\_\_\_\_ ×106 J\times 10^{6}\text{ }J. (Consider air as diatomic molecule)

  4. Question 4

    This type asked 6 times: 2021 Paper 13, 2021 Paper 24, 1 Feb 2023, 27 Jan 2024, 31 Jan 2024, 28 Jan 2025. This one: 28 Jan 2025 See all 6 of this type

    80
    The kinetic energy of translation of the molecules in 50 g of CO2CO_{2} gas at 17∘C17^{\circ}C is :

    Tap an option to check your answer.

  5. Question 5

    This type asked 5 times: 25 Jun 2022, 29 Jan 2023, 29 Jan 2025, 3 Apr 2025, 24 Jan 2026 S1. This one: 24 Jan 2026 S1 See all 5 of this type

    22
    A gas of certain mass filled in a closed cylinder at a pressure of 3.23 kPa has temperature 50∘C50^{\circ}C. The gas is now heated to double its temperature. The modified pressure is ____\_\_\_\_ Pa.

  6. Question 6

    This type asked 5 times: 28 Jun 2022, 28 Jul 2022, 24 Jan 2023, 25 Jan 2023, 6 Apr 2023. This one: 6 Apr 2023 See all 5 of this type

    105
    The temperature of an ideal gas is increased from 200 K200\text{ }K to 800 K800\text{ }K. If r.m.s. speed of gas at 200 K200\text{ }K is v0v_{0}. Then, r.m.s. speed of the gas at 800 K800\text{ }K will be:

    Tap an option to check your answer.

  7. Question 7

    Asked 4 times: 26 Jun 2022*, 30 Jan 2023*, 15 Apr 2023*, 7 Apr 2025 (* = numbers or wording changed that year) See all 4 times it was asked

    82
    The helium and argon are put in the flask at the same room temperature ( 300 K ). The ratio of average kinetic energies (per molecule) of helium and argon is : (Give : Molar mass of helium =4 g/mol= 4\text{ }g/mol, Molar mass of argon =40 g/mol= 40\text{ }g/mol )

    Tap an option to check your answer.

  8. Question 8

    This type asked 4 times: 2021 Paper 6, 13 Apr 2023, 5 Apr 2024, 28 Jan 2026 S2. This one: 28 Jan 2026 S2 See all 4 of this type

    4
    The mean free path of a molecule of diameter 5×10−10 m5 \times 10^{- 10}\text{ }m at the temperature 41∘C41^{\circ}C and pressure 1.38×105 Pa1.38 \times 10^{5}\text{ }Pa, is given as ____\_\_\_\_ m. (Given kB=1.38×10−23 J/Kk_{B} = 1.38 \times 10^{- 23}\text{ }J/K).

    Tap an option to check your answer.

  9. Question 9

    This type asked 4 times: 6 Apr 2023, 5 Apr 2024, 4 Apr 2025, 22 Jan 2026 S2. This one: 22 Jan 2026 S2 See all 4 of this type

    3
    Consider two boxes containing ideal gases A and B such that their temperatures, pressures and number densities are same. The molecular size of A is half of that of B and mass of molecule A is four times that of B. If the collision frequency in gas B is 32×10832 \times 10^{8}/s then collision frequency in gas A is ____\_\_\_\_ /s.

    Tap an option to check your answer.

  10. Question 10

    This type asked 4 times: 29 Jul 2022, 29 Jan 2024, 30 Jan 2024, 1 Feb 2024. This one: 1 Feb 2024 See all 4 of this type

    6
    Two moles of a monoatomic gas is mixed with six moles of a diatomic gas. The molar specific heat of the mixture at constant volume is:

    Tap an option to check your answer.