NEET UG - Heat and temperature, thermal expansion, specific heat capacity, calorimetry, change of state and latent heat Online Test (MCQ Quiz)

1. What is the SI unit of temperature?

A) Celsius B) Fahrenheit C) Kelvin D) Rankine

2. Which of the following best describes temperature?

A) The total kinetic energy of molecules in a substance. B) The average kinetic energy of molecules in a substance. C) The potential energy stored in the bonds of molecules. D) The amount of heat energy transferred between objects.

3. Thermal expansion is generally the tendency of matter to:

A) Contract in volume when heated. B) Expand in volume when heated. C) Expand in volume when cooled. D) Remain unchanged in volume when heated or cooled.

4. Which state of matter typically exhibits the largest coefficient of thermal expansion?

A) Solid B) Liquid C) Gas D) Plasma

5. The coefficient of linear expansion for a solid is defined as the fractional change in:

A) Volume per unit change in temperature. B) Area per unit change in temperature. C) Length per unit change in temperature. D) Density per unit change in temperature.

6. If a metal rod expands by 0.1% when heated by 10°C, what is its coefficient of linear expansion?

A) 10⁻⁵ /°C B) 10⁻⁴ /°C C) 10⁻³ /°C D) 10⁻² /°C

7. Bimetallic strips are used in thermostats because:

A) Different metals have the same coefficient of thermal expansion. B) Different metals have different coefficients of thermal expansion. C) Metals contract significantly when heated. D) Metals change color with temperature.

8. What is specific heat capacity?

A) The amount of heat required to raise the temperature of 1 kg of a substance by 1°C. B) The total heat content of a substance. C) The rate at which heat is transferred through a substance. D) The temperature at which a substance changes state.

9. Which of the following has the highest specific heat capacity?

A) Iron B) Aluminum C) Water D) Copper

10. The unit of specific heat capacity is typically:

A) Joule/kg B) Joule/°C C) Joule/kg·°C D) Watt/kg·°C

11. Calorimetry is the science associated with measuring:

A) Temperature B) Heat transfer C) Pressure D) Volume

12. In a calorimetry experiment, a hot object is placed in a perfectly insulated container with a cooler object. Heat will flow from:

A) The cooler object to the hotter object until temperatures are equal. B) The hotter object to the cooler object until temperatures are equal. C) Both objects to the surroundings. D) Neither object, as the container is insulated.

13. The principle of calorimetry states that in an isolated system, the heat lost by the hot substance is equal to:

A) The heat gained by the surroundings. B) The heat gained by the cooler substance. C) The total heat energy of the system. D) Zero, if no phase change occurs.

14. What is the 'change of state' in physics?

A) A change in the temperature of a substance. B) A change in the volume of a substance. C) A transition of a substance from one physical state (solid, liquid, gas) to another. D) A change in the color of a substance.

15. Which process involves a change of state from solid to liquid?

A) Condensation B) Evaporation C) Melting (Fusion) D) Sublimation

16. The temperature at which a solid melts into a liquid at a given pressure is called the:

A) Boiling point B) Freezing point C) Melting point D) Triple point

17. What is the process of a liquid changing into a gas called?

A) Freezing B) Condensation C) Boiling (Vaporization) D) Deposition

18. The temperature at which a liquid boils and turns into a gas at a given pressure is its:

A) Melting point B) Freezing point C) Triple point D) Boiling point

19. What is latent heat?

A) The heat absorbed or released during a change of state at constant temperature. B) The heat required to raise the temperature of 1 kg of a substance by 1°C. C) The total heat energy of a substance. D) The heat transferred due to conduction.

20. Latent heat of fusion refers to the heat absorbed or released during:

A) Boiling and condensation. B) Melting and freezing. C) Sublimation and deposition. D) Evaporation and condensation.

21. Latent heat of vaporization refers to the heat absorbed or released during:

A) Melting and freezing. B) Sublimation and deposition. C) Boiling and condensation. D) Evaporation and freezing.

22. The unit of latent heat is typically:

A) Joule/kg·°C B) Joule/kg C) Joule/°C D) Watt/kg

23. When ice at 0°C melts into water at 0°C, heat is:

A) Released B) Absorbed C) Neither absorbed nor released D) Converted to kinetic energy.

24. Water boils at 100°C at standard atmospheric pressure. This is its:

A) Melting point B) Triple point C) Boiling point D) Critical point

25. Which of the following phenomena is an example of sublimation?

A) Ice melting into water. B) Water turning into steam. C) Dry ice (solid CO₂) turning directly into carbon dioxide gas. D) Steam condensing into water.

26. The specific heat capacity of water is approximately 4186 J/kg·°C. How much heat is required to raise the temperature of 2 kg of water by 10°C?

A) 4186 J B) 8372 J C) 41860 J D) 83720 J

27. A block of metal has a coefficient of linear expansion of 12 x 10⁻⁶ /°C. If its length is 1 meter at 20°C, what will be its length at 120°C?

A) 1.00012 m B) 1.0012 m C) 1.012 m D) 1.12 m

28. A substance requires 500 J of heat to change its state. If its mass is 0.5 kg, what is its latent heat?

A) 250 J/kg B) 500 J/kg C) 1000 J/kg D) 2500 J/kg

29. When a liquid evaporates, it:

A) Absorbs heat from the surroundings. B) Releases heat to the surroundings. C) Changes its specific heat capacity. D) Increases its boiling point.

30. The triple point of water is the temperature and pressure at which:

A) Water boils. B) Water freezes. C) Water, ice, and steam coexist in equilibrium. D) Water sublimes.

31. Which temperature scale is an absolute scale, meaning 0 K represents the lowest possible temperature?

A) Celsius B) Fahrenheit C) Kelvin D) Réaumur

32. Absolute zero is approximately:

A) 0°C B) -273.15°C C) 32°F D) 100°C

33. The thermal expansion of solids is generally:

A) Anisotropic (different in different directions). B) Isotropic (same in all directions). C) Negligible. D) Always negative.

34. If the coefficient of volume expansion of a liquid is γ, then its coefficient of superficial expansion is approximately:

A) γ/3 B) 2γ/3 C) γ D) 3γ

35. The heat required to change the state of 1 gram of a substance without changing its temperature is called:

A) Specific heat capacity B) Specific latent heat C) Heat capacity D) Heat of combustion

36. Which of the following statements about heat and temperature is correct?

A) Heat is a measure of the average kinetic energy of molecules. B) Temperature is a measure of the total kinetic energy of molecules. C) Heat is energy in transit due to temperature difference. D) A substance with high specific heat capacity heats up quickly.

37. A metal sphere is heated. Its volume will:

A) Decrease. B) Increase. C) Remain the same. D) First decrease then increase.

38. Which of the following substances has the lowest melting point?

A) Water B) Iron C) Gold D) Mercury

39. What is the latent heat of fusion of ice?

A) 2.26 x 10⁶ J/kg B) 3.34 x 10⁵ J/kg C) 4186 J/kg D) 100 J/kg

40. If a substance is heated and its temperature does not change, it must be undergoing:

A) A change in specific heat capacity. B) A change of state. C) An increase in thermal conductivity. D) A decrease in its coefficient of expansion.

41. The specific heat capacity of a gas at constant pressure is generally greater than its specific heat capacity at constant volume because:

A) More heat is required to raise the temperature at constant pressure. B) The gas does work on the surroundings at constant pressure. C) The gas absorbs less heat at constant pressure. D) The internal energy change is less at constant pressure.

42. A railway track is laid with gaps between the rails because:

A) It reduces friction. B) It allows for thermal expansion. C) It improves the sound insulation. D) It makes maintenance easier.

43. Which of the following is an example of thermal expansion in everyday life?

A) A refrigerator cooling food. B) A pot of water boiling. C) A thermometer measuring body temperature. D) A jar lid being loosened by running hot water over it.

44. What is the relationship between heat (Q), mass (m), specific heat capacity (c), and temperature change (ΔT)?

A) Q = mc/ΔT B) Q = mΔT/c C) Q = m c ΔT D) Q = ΔT / (mc)

45. The latent heat of vaporization of water at 100°C is approximately 2.26 x 10⁶ J/kg. How much heat is required to vaporize 1 kg of water at 100°C?

A) 4186 J B) 100 J C) 2.26 x 10⁶ J D) 3.34 x 10⁵ J

46. When a liquid is cooled below its freezing point without solidifying, it is called:

A) Superheated liquid B) Supercooled liquid C) Sublimated liquid D) Vaporized liquid

47. The coefficient of area expansion is approximately how many times the coefficient of linear expansion for an isotropic solid?

A) 1/2 B) 2/3 C) 1 D) 2

48. Which process involves a direct transition from gas to solid?

A) Evaporation B) Condensation C) Sublimation D) Deposition

49. If the temperature of a substance is increased, its specific heat capacity generally:

A) Increases significantly. B) Decreases significantly. C) Remains constant. D) May increase or decrease slightly depending on the substance and temperature range.

Heat and temperature, thermal expansion, specific heat capacity, calorimetry, change of state and latent heat - Online Test

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