Thermal Properties of Matter Mock Test – Class 11 Physics

1. For a solid rod heated through a small temperature range, the increase in length is represented by:

2. A thermos flask has a vacuum between its double walls and silvered surfaces. If the vacuum is lost but the silvering remains, which heat-transfer mode increases most directly between the walls?

3. The SI unit of thermal conductivity is:

4. Consider the following statements about Newton’s law of cooling.
Statement I: It is most accurate for small temperature differences between the body and surroundings.
Statement II: The cooling rate decreases as the body approaches surrounding temperature.
Statement III: It says the cooling rate is independent of the surrounding temperature.

5. A graph is drawn between thermal stress and temperature rise for a fully constrained rod, assuming and remain constant. The graph is expected to be:

6. A metal ball just passes through a metal ring at room temperature. Later, both the ball and the ring are heated uniformly by the same temperature rise, and both are made of the same material. The ball will most nearly:

7. A ring made of metal is heated and then slipped onto a shaft. After cooling, it grips the shaft tightly. The sequence of size changes is:

8. A black body has peak emission wavelength . Taking Wien’s constant , and , what is the emitted power per unit area?

9. A thermometer is kept in contact with a patient’s body for some time before the reading is taken. Why is this waiting time needed?

10. A resistance thermometer uses the fact that the resistance of a metal wire changes with temperature. If the thermometer is to be reliable, the resistance should:

11. A glass tumbler may crack when very hot water is poured into it suddenly. The most suitable explanation is:

12. Woollen clothes help keep a person warm mainly because wool:

13. A body of specific heat capacity loses of heat. If there is no phase change, its temperature change is:

14. A sample of steam at condenses completely to water at . If , how much heat is released?

15. A liquid thermometer is made with a very wide capillary tube instead of a narrow one. For the same volume expansion of liquid, what happens to the movement of the liquid column?

16. The SI unit of specific latent heat is:

17. A sample of steam at is passed into water at in an insulated vessel. Take and . Assuming all steam condenses, what is the final temperature?

18. A metal block at is kept in contact with another block at . Before they reach the same temperature, the direction of natural heat flow is:

19. The rate of heat conduction through a slab is larger when:

20. A metal rod conducts heat steadily from one end to the other. If the heat current is , the amount of heat conducted in time is:

21. Two objects and are placed in thermal contact. Object is initially at , and object is initially at . What is expected immediately after contact, assuming no phase change or chemical reaction?

22. A metal block at is dropped into water at . Some water changes into steam at , and the final state contains water and steam at . If , , and , what mass of water vaporises?

23. Study the table and identify the row in which the conversion idea is used properly.

24. A shallow dish contains of water at . Due to evaporation, of water leaves the surface. Assume the latent heat needed for evaporation is taken only from the remaining water, , and . What is the approximate final temperature of the remaining water?

25. A sample of water at is placed in a low-pressure chamber where water boils at . Some water evaporates, and the remaining water cools to . If no heat enters from outside, and , what approximate mass of water evaporates?

26. A square metal plate is heated uniformly. Its side length increases by a small fraction . The approximate fractional increase in its area is:

27. A thermometer is in thermal equilibrium with object . The same thermometer is also in thermal equilibrium with object . The conclusion that and have the same temperature relies most directly on:

28. A body is heated from to . In the relation , the correct value of is:

29. Volume expansion of an isotropic solid is described by:

30. A body has temperature , and the surroundings are at . Another identical body has temperature in the same surroundings. Using Newton’s law of cooling, the ratio of initial cooling rates of the two bodies is:

31. Linear expansion formulas are usually written for small temperature changes. The main reason is that:

32. A thermos flask is filled with hot liquid and closed. After a long time, the liquid cools slightly. This does not violate the design aim because:

33. Consider the following statements about temperature scales.
Statement I: corresponds to about .
Statement II: A temperature interval of equals a temperature interval of .
Statement III: A body at has an absolute temperature of .

34. Two rods are connected in parallel between the same hot and cold reservoirs. Rod and rod have the same length and area, but . The ratio of heat currents is:

35. Consider the following statements about latent heat.
Statement I: During melting of a pure solid, heat can be absorbed at constant temperature.
Statement II: During condensation, latent heat is released.
Statement III: Specific latent heat has unit .

36. In a mixture of two bodies inside an insulated container, the final temperature comes out exactly midway between the two initial temperatures. This is most naturally expected when the two bodies have:

37. A body is losing heat by radiation to surroundings. The surrounding temperature is not negligible. The net radiation formula uses instead of only because:

38. If is the coefficient of real expansion of a liquid and is the coefficient of volume expansion of the vessel, the coefficient of apparent expansion is approximately:

39. A body is in thermal equilibrium with body . Body is not in thermal equilibrium with body . What conclusion is most reasonable?

40. The coefficient of linear expansion has the unit:

41. Ice floats on water mainly because:

42. A heater is used to warm of water from to . If only of the heater energy reaches the water, how long does the heating take? Take .

43. In a constant-volume gas thermometer, the pressure of the gas is used as the thermometric property. Why must the volume be kept constant?

44. A composite slab has two layers in series with thermal resistances and . A temperature difference of is maintained across the whole slab. The steady heat current is:

45. A steel rod is fixed rigidly between two massive supports, so its thermal expansion is completely prevented. The rod has , , cross-sectional area , and its temperature is raised by . What force does the rod exert on the supports, assuming the rod remains within the elastic limit?

46. The melting point of ice is lowered by about for each atmosphere increase of pressure. A piece of ice is at . Approximately how much extra pressure is needed to lower its melting point to this temperature?

47. A long concrete road is divided into slabs with small spaces between them. These spaces are useful because:

48. A steel rod has , , and its expansion is fully prevented. If its temperature rises by , what thermal stress is produced?

49. A heating curve for a pure substance has two horizontal portions. The first horizontal portion occurs at melting point and the second at boiling point. The second horizontal portion is generally longer for the same mass and same heating rate if:

50. Assertion: Heating a substance may increase its internal energy.
Reason: Heat supplied to a body can change random molecular motion or molecular arrangement depending on the process.