Kinetic Theory Mock Test – Class 11 Physics

1. An ideal gas has . If its heat capacities are explained by active degrees of freedom with vibrations neglected, the most suitable interpretation is

2. A gas sample of is divided equally into two identical containers without loss. The number of molecules in each container is

3. In gas equations, the symbol is best interpreted as

4. Select the rows whose judgements are correct.

5. The unit of number density is ______.

6. Consider the following statements about , , , , and .
I. .
II. .
III. .

7. A formula sheet shows the two relations and . The safest way to choose between them is to check whether the data gives

8. In a dilute gas, increasing the number density while keeping molecular diameter unchanged makes the mean free path

9. Match the quantities with their meanings.

10. A molecule of mass hits a wall normally with speed and rebounds elastically. The magnitude of impulse delivered to the wall is

11. Two ideal gases are at the same temperature. Gas P has lighter molecules than gas Q. The best comparison is that

12. The average time between successive molecular collisions is called the mean free time. If mean free path is and representative speed is , then the mean free time is

13. A monatomic gas contains molecules at pressure , volume , and temperature . What is the average translational kinetic energy per molecule divided by the total translational kinetic energy of the gas?

14. A cubical container has side , so the area of one wall is and the volume is . If the total force on one wall is , the pressure on that wall is

15. In the ideal-gas kinetic model, molecules are treated as point particles because their own volume is assumed to be

16. A gas at constant pressure is heated from to . Molecular diameter is unchanged. If its initial mean free path is and initial collision frequency is , the final mean free path and collision frequency are

17. Equal volumes of different gases at the same temperature and pressure contain

18. A non-linear polyatomic ideal gas is treated as having active degrees of freedom. Its , , and are

19. One mole of any substance contains approximately

20. Use the arrangement described below.

The number density in box Q is

21. A sealed container filled with air is kept on a table. The pressure exerted by the air on the side walls is mainly due to

22. A gas sample is claimed to be monatomic because its measured molar heat capacity at constant volume is about . Taking , the claim is

23. A gas molecule has rms speed and mean free path . A useful estimate of collision frequency is

24. For identical molecules in a cubical vessel of side , the total force on one wall perpendicular to the -axis can be written as

25. Nitrogen gas has molar mass . Taking , the mass of one nitrogen molecule is closest to

26. Use the arrangement described below.

If is made larger while number density is unchanged, the mean free path generally

27. A fixed mass of gas at constant pressure occupies at . Its volume at is

28. Assertion: Gas pressure on a container wall is produced by molecular impacts on that wall.
Reason: During a wall collision, a molecule changes momentum and transfers impulse to the wall.

29. Consider the following assumptions used in the kinetic theory of an ideal gas.
I. Molecules are identical for a pure gas sample.
II. Molecules move randomly in all directions.
III. Strong attractive forces act between molecules throughout their motion.

30. A graph is drawn for a fixed amount of gas at constant temperature with on the vertical axis and on the horizontal axis. The graph should be

31. A gas is at pressure , temperature , and has molecular diameter . If the pressure is tripled, temperature is doubled, and molecular diameter is also doubled, the new mean free path in terms of the old mean free path is

32. A gas is heated from to . For the same gas, the rms speed changes by a factor of

33. Consider the following statements about the molecular view of matter.
I. Matter is made of atoms and molecules.
II. A gas sample looks continuous because its molecules are large enough to be seen separately.
III. Macroscopic gas pressure can be connected to microscopic molecular impacts.

34. A gas mixture in a rigid vessel contains helium and hydrogen at the same temperature . If their molar masses are and , the ratio is

35. A gas sample has molecules in . What is its number density in ?

36. In a fixed-volume gas sample, a process makes three times larger while and stay the same. The kinetic-theory pressure becomes

37. A gas at has molecular diameter . Its pressure is . Using and , its mean free path is closest to

38. A gas of molar mass has rms speed at temperature . Another gas at temperature has the same rms speed. Its molar mass is

39. A gas of molar mass has rms speed . Taking , its absolute temperature is closest to

40. A graph is drawn for a fixed amount of ideal gas with on the vertical axis and on the horizontal axis. The straight-line slope represents

41. A derivation of gas pressure accidentally uses instead of . The main problem is that

42. Comparing with gives the molecular energy relation

43. A fixed sample of ideal gas is compressed isothermally from to . If its initial mean free path is , the final mean free path and final pressure are respectively

44. A graph description says that pressure is plotted against density for gas samples with the same . The expected graph is

45. A gas is so dense that the distance between molecules becomes comparable with molecular size. The simple mean-free-path formula becomes less reliable mainly because

46. The unit of in the ideal-gas equation is

47. A monatomic ideal gas and a diatomic ideal gas at ordinary temperature each contain and are heated by at constant volume. Using , the difference in heat supplied to the two gases is

48. Match the molecular motion type with the best description.

49. Study the table and select the assumptions that belong to the kinetic theory of an ideal gas.

50. The same ideal gas is compared in two states. In state P, and . In state Q, and . The density in state Q is