MCQOPTIONS
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MCQOPTIONS
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*10-20 |
| B. | 6.38*10-20 |
| C. | 3.86*10-20 |
| D. | 4.58*10-20 |
| Answer» B. 6.38*10-20 | |
| 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*10-20J |
| B. | 0.53*10-20J |
| C. | 0.01*10-20J |
| D. | 0.45*10-20J |
| Answer» B. 0.53*10-20J | |
| 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*10-20Pa |
| B. | 20/3*10-20Pa |
| C. | 20/3*10-19Pa |
| D. | 20*10-19Pa |
| Answer» B. 20/3*10-20Pa | |
| 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*10-19N |
| B. | 4*10-21N |
| C. | 4/3*10-21N |
| D. | 4/3*10-19N |
| Answer» C. 4/3*10-21N | |
| 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 | |