Kinetic Theory of Gases · JEE Main previous year questions

2024 7 questions

1. Q442024 · 8 Apr 2024 · Shift 2

   Given below are two statements : Statement (I) : The mean free path of gas molecules is inversely proportional to square of molecular diameter. Statement (II) : Average kinetic energy of gas molecules is directly proportional to absolute temperature of gas. In the light of the above statements, choose the correct answer from the options given below :

   1. A.Statement I is false but Statement II is true
   2. B.Both Statement I and Statement II are true
   3. C.Statement I is true but Statement II is false
   4. D.Both Statement I and Statement II are false
   Show answer

   Answer: B

2. Q392024 · 6 Apr 2024 · Shift 2

   Energy of 10 non rigid diatomic molecules at temperature $T$ is :

   1. A.$35\mathrm{RT}$
   2. B.$\frac{7}{2}\mathrm{RT}$
   3. C.$70{\mathrm{K}}_{\mathrm{B}}\mathrm{T}$
   4. D.$35{\mathrm{K}}_{\mathrm{B}}\mathrm{T}$
   Show answer

   Answer: D

3. Q502024 · 5 Apr 2024 · Shift 2

   If $n$ is the number density and $d$ is the diameter of the molecule, then the average distance covered by a molecule between two successive collisions (i.e. mean free path) is represented by :

   1. A.$\frac{1}{\sqrt{2}n\pi d^2}$
   2. B.$\frac{1}{\sqrt{2}{n}^2{\pi }^2{d}^2}$
   3. C.$\frac{1}{\sqrt{2n}\pi d^2}$
   4. D.$\sqrt{2}n\pi d^2$
   Show answer

   Answer: A

4. Q442024 · 4 Apr 2024 · Shift 1
   
   1. A.${\rho }_1>{\rho }_2$
   2. B.${\rho }_2<{\rho }_3$
   3. C.${\rho }_1={\rho }_2={\rho }_3$
   4. D.${\rho }_1<{\rho }_2$
   Show answer

   Answer: A

5. Q442024 · 4 Apr 2024 · Shift 2

   The translational degrees of freedom $(f_t)$ and rotational degrees of freedom $(f_r)$ of ${\text{CH}}_4$ molecule are:

   1. A.$f_t=2$ and $f_r=2$
   2. B.$f_t=3$ and $f_r=3$
   3. C.$f_t=3$ and $f_r=2$
   4. D.$f_t=2$ and $f_r=3$
   Show answer

   Answer: B

6. Q462024 · 29 Jan 2024 · Shift 2

   $N$ moles of a polyatomic gas ($f=6$) must be mixed with two moles of a monoatomic gas so that the mixture behaves as a diatomic gas. The value of $N$ is :

   1. A.6
   2. B.2
   3. C.4
   4. D.3
   Show answer

   Answer: C

7. Q502024 · 27 Jan 2024 · Shift 1

   The average kinetic energy of a monatomic molecule is $0.414\text{ eV}$ at temperature : (Use $K_B=1.38\times 10^{-23}\text{ J/mol}-\text{K}$)

   1. A.$3000\text{ K}$
   2. B.$3200\text{ K}$
   3. C.$1600\text{ K}$
   4. D.$1500\text{ K}$
   Show answer

   Answer: B