Explore topic-wise MCQs in Physics.

This section includes 9 Mcqs, each offering curated multiple-choice questions to sharpen your Physics knowledge and support exam preparation. Choose a topic below to get started.

1.

Boyle s law can be deduced from kinetic theory. True or False?

A. True
B. False
Answer» B. False
2.

What is the number of molecules in 3 cubic metre of a gas at 3atm & 27 C?

A. 2.17*10<sup>-20</sup>
B. 6.38*10<sup>-20</sup>
C. 3.86*10<sup>-20</sup>
D. 4.58*10<sup>-20</sup>
Answer» B. 6.38*10<sup>-20</sup>
3.

A container has 3 gases whose mass ratio is 1:3:5. What is the ratio of mean square speed of the molecules of two gases? Their atomic masses are 20u, 30u & 40u corresponding to the order in which the ratios are given.

A. 2:3:4
B. 4:3:2
C. 2: 3: 2
D. 2: 3:2
Answer» C. 2: 3: 2
4.

Average kinetic energy of a gas depends on which of the following factors?

A. Nature of gas
B. Temperature
C. Pressure
D. Volume
Answer» C. Pressure
5.

The number of molecules per unit volume in the sample is 20. The mass of each molecule is 10-20kg. The mean of speed squared is 4m2/s2. What is the value of internal energy of the gas? Assume volume of container is 0.02m3.

A. 0.8*10<sup>-20</sup>J
B. 0.53*10<sup>-20</sup>J
C. 0.01*10<sup>-20</sup>J
D. 0.45*10<sup>-20</sup>J
Answer» B. 0.53*10<sup>-20</sup>J
6.

Which of the following is not an assumption of KTG?

A. Time spent during collision is negligibly small
B. All gases are made up of molecules moving randomly in all directions
C. Molecules do not collide with each other
D. Molecules collide elastically with the wall
Answer» D. Molecules collide elastically with the wall
7.

Consider a gas inside a box. It exerts some pressure on its walls. Find this value. GIven that number of molecules per unit volume be 20, mass of each molecule 10-20kg, vx2 = 1m2/s2.

A. 20*10<sup>-20</sup>Pa
B. 20/3*10<sup>-20</sup>Pa
C. 20/3*10<sup>-19</sup>Pa
D. 20*10<sup>-19</sup>Pa
Answer» B. 20/3*10<sup>-20</sup>Pa
8.

Consider a gas enclosed in a box. Let the walls have an area of 0.01m2. Let s say a few molecules having their x-component of velocity =2m/s, hit a wall parallel to the yz plane. What will be the value of force on the wall in time dt? Let the number of molecules per unit volume be 10 & mass of each molecule be 10-20kg.

A. 4*10<sup>-19</sup>N
B. 4*10<sup>-21</sup>N
C. 4/3*10<sup>-21</sup>N
D. 4/3*10<sup>-19</sup>N
Answer» C. 4/3*10<sup>-21</sup>N
9.

Consider a gas enclosed in a box. A molecule of mass m, having a velocity -2i+3j+4k collides with a wall parallel to the xz plane. What will be its velocity after collision and its change in momentum? i,j & k are unit vectors along the x,y & z axis.

A. -2i-3j+4k, -6mj
B. 2i+3j-4k, -6mj
C. -2i-3j+4k, 6mj
D. 2i+3j-4k, 6mj
Answer» B. 2i+3j-4k, -6mj