Kinetic Theory Mock Test – Class 11 Physics

1. Read the situation below and choose the best microscopic explanation.

2. A gas has , , and molecular diameter . Another state of the same gas has , , and the same . If the initial mean free path is , the final mean free path is

3. A gas mixture contains of a monatomic gas and of a diatomic gas at ordinary temperature. If the mixture is heated by at constant volume, using , the heat supplied is closest to

4. In one state, a gas has mean free path at pressure and temperature . The same gas is taken to pressure and temperature , with molecular diameter unchanged. The new mean free path is

5. A real gas is most likely to behave nearly like an ideal gas when it is

6. A gas is changed so that its pressure becomes , temperature becomes , and molecular diameter remains unchanged. If its initial mean free time is , the final mean free time is

7. For a diatomic ideal gas at ordinary temperature with , the molar heat capacity at constant volume is

8. A molecule in a cubical box has , and the side of the cube is . The time between its successive hits on the same wall perpendicular to the -axis is

9. A claim says, “A gas with larger must always have larger .” The best evaluation is that

10. A speed-distribution graph for a gas is drawn at two temperatures. The higher-temperature curve has a lower peak. This lower peak does not mean fewer molecules if the sample size is unchanged because

11. Use the graph description below.

The slope of this graph is

12. A closed rigid vessel contains of a monatomic ideal gas and of a diatomic ideal gas at ordinary temperature. If the mixture is heated from to , using , the increase in internal energy is closest to

13. One mole of a monatomic ideal gas has translational kinetic energy

14. Study the table and identify the row that best represents molecular size and separation in a gas.

15. A container has molecules of gas P and molecules of gas Q at the same temperature and volume . For an ideal mixture, the total pressure is

16. Read the situation below and answer the question.

This molecular picture is most directly related to

17. Gas sample X has molecular diameter , pressure , temperature , and mean free path . Gas sample Y has effective molecular diameter , pressure , and temperature . Assuming the same mean-free-path model, the mean free path of Y is

18. A graph-style description says that, for an equilibrium gas, three bars represent , , and . The most suitable bar chart would show

19. Equal-volume samples of two gases are kept at the same temperature and pressure. If sample P contains molecules, sample Q contains

20. A real gas occupies a small vessel at high pressure. A statement says, “The volume of the molecules can still always be ignored.” The best evaluation is that

21. The relation is needed because

22. A sealed syringe contains air, and its nozzle is blocked. When the piston is pushed slowly inward, the air volume decreases noticeably. This is possible mainly because

23. Consider the following statements about a molecule colliding elastically with a wall perpendicular to the -axis.
I. The -component of velocity reverses sign.
II. The components parallel to the wall remain unchanged.
III. The speed becomes zero immediately after the collision.

24. A graph of internal energy versus absolute temperature is drawn for a fixed amount of monatomic ideal gas. The slope of the graph is

25. From , the rms speed of a molecule of mass is

26. Consider the following statements about ideal and real gases.
I. An ideal gas is a model, not a perfectly obtainable substance under all conditions.
II. Real gases tend to deviate more from ideal behaviour at high pressure and low temperature.
III. The ideal-gas model assumes strong attraction between molecules at all separations.

27. In a cubical container of side , a molecule with -component travels between the two opposite walls perpendicular to the -axis. The time between two successive collisions with the same wall is

28. Match each gas law with its constant condition.

29. A molecule-molecule collision in the kinetic theory of an ideal gas is taken to be perfectly elastic. This means

30. A vessel of volume contains molecules of mass . If , the pressure of the gas is

31. If an ideal gas has active degrees of freedom, its molar heat capacity at constant pressure is

32. In the derivation of gas pressure, the force contribution of a molecule to an -wall contains rather than mainly because

33. Consider the following statements about mean free path.
I. It is an average distance, not the exact same path length before every collision.
II. It decreases when number density increases.
III. It increases when molecular collision diameter increases.

34. A container has molecules of an ideal gas at temperature . If and are kept fixed while the volume is doubled, the pressure becomes

35. Equal volumes of helium and oxygen are kept at the same and . If the helium sample contains molecules, the oxygen sample contains

36. Brownian motion supports the molecular theory of matter because it shows that

37. A gas has density and rms speed . Its pressure according to is

38. Use the arrangement described below.

During the free part of its motion between collisions, the molecule is assumed to move

39. A data table lists some constants used in kinetic theory. Identify the row that needs correction.

40. Which statement gives the best comparison between molecular motion in a liquid and in a gas?

41. A mixture contains of a monatomic ideal gas and of a diatomic ideal gas at ordinary temperature, all at the same . The total internal energy of the mixture is closest to

42. A molecule has the same speed in two cases but different directions. In Case 1, it moves almost parallel to a chosen wall; in Case 2, it moves nearly perpendicular to that wall. The pressure contribution on that wall is larger in

43. A monatomic ideal gas has and . It changes to a state where and . The change in internal energy is

44. A graph of pressure versus for a gas sample is a straight line through the origin. The slope of the graph is . The density of the gas and the pressure when are respectively

45. The relation connecting the gas constant , Avogadro's constant , and Boltzmann constant is

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

47. A rigid container holds a fixed amount of ideal gas. The pressure-temperature graph is linear only when the temperature axis is marked in

48. In a container of gas at equilibrium, the molecules are moving randomly. The average effect of this random motion is that the gas

49. Helium has molar mass , and methane has molar mass . At the same temperature, the ratio is

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