Kinetic Theory Mock Test – Class 11 Physics

1. The same ideal gas is heated through once at constant pressure and once at constant volume. The extra heat required at constant pressure is

2. A monatomic ideal gas has at . It is cooled at constant volume until its pressure becomes of the original pressure. Using , the decrease in internal energy is closest to

3. A fixed amount of monatomic ideal gas is compressed so that its temperature rises from to . The ratio of final to initial internal energy is

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

5. A gas molecule has mass . At a certain temperature its rms speed is . Taking , the temperature of the gas is closest to

6. A statement about gases says, “The molecules in a gas are far apart, so there is no interaction of any kind.” The most accurate correction is that

7. For a fixed amount of gas, Boyle's law states that at constant temperature

8. A derivation step states that the total force on one wall is obtained by adding terms like , , , and so on. This addition is needed because

9. A gas sample has pressure , volume , and molecules. Taking , its temperature is closest to

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

11. A gas is pumped out of a vessel so that the number density decreases greatly. The mean free path of the remaining molecules becomes

12. In the formula , the factor appears because

13. A gas is heated while its volume is allowed to expand, and its pressure is found to change only slightly. Boyle's law should not be directly applied to this change because

14. A gas has and mean free path . If the temperature is made four times as large while the number density and molecular diameter remain unchanged, the new collision frequency is

15. A molecule of mass moves toward a plane wall with velocity components , , and . If the wall is perpendicular to the -axis and the collision is elastic, the component that reverses is

16. A gas molecule of mass is in a gas whose pressure is and number density is . Its rms speed is closest to

17. According to the law of equipartition of energy, each active quadratic degree of freedom contributes an average energy of

18. A pressure gauge on a sealed rigid cylinder shows a higher reading after the cylinder is warmed. The most suitable microscopic explanation is that

19. The main molecular-level difference between a gas and a solid is that gas molecules

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

21. If the absolute temperature of an ideal gas is doubled, the average translational kinetic energy per molecule becomes

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

23. A gas has pressure and density . The rms speed of its molecules is

24. A diatomic ideal gas at ordinary temperature has at . If , its internal energy and are closest to

25. A molecule has and mean free path . Its approximate collision frequency is

26. A gas sample has density , pressure , and molar mass . Using , its temperature is closest to

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

28. A smoke particle suspended in air moves irregularly instead of following a smooth straight path. The most suitable reason is that

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

30. A gas at is heated to . A learner says the rms speed increases by a factor of . The correction is that the factor should be

31. A graph is plotted with on the vertical axis and on the horizontal axis for the same ideal gas. The graph should be

32. Use the table below for an ideal-gas mixture in the same container at the same temperature.

The partial pressure of gas Q is

33. 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

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

35. An ideal gas has . A sample is heated by at constant pressure. Using , the heat supplied is closest to

36. A gas-law graph is drawn for a fixed amount of gas. The horizontal axis is absolute temperature , and the vertical axis is pressure . The graph is a straight line through the origin. This graph is consistent with

37. 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.

38. The order of magnitude of a typical molecular diameter is closest to

39. For an ideal gas, internal energy is mainly interpreted in kinetic theory as

40. A model-boundary statement says, “Equipartition must give the exact heat capacity of every substance at every temperature.” The best correction is that equipartition

41. An ideal gas has at . Taking , its molar mass is closest to

42. A monatomic ideal gas has at . Using , its internal energy is closest to

43. Helium and oxygen are kept at the same pressure and temperature. Taking their molar masses as and , respectively, the correct comparison is

44. A sealed container has a gas that is far from liquefaction and at low density. In applying the ideal-gas equation, the most reasonable assumption is that

45. A monatomic molecule moving freely in three-dimensional space has

46. A gas has pressure , molar mass , and absolute temperature . From the ideal-gas equation, its density is

47. A gas sample is described by . The unit of must be

48. A molecule of mass moves inside a cubical vessel of side . Its velocity component perpendicular to one wall is . For elastic collisions with that wall, the average force on the wall due to this molecule is

49. Study the table and select the row that correctly applies Charles' law.

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