CBSE  /  Class 11  /  Physics  /  Thermodynamics

  • 1. 
    Directions: The following question has four choices out of which ONLY ONE is correct.
    A thermodynamical system is changed from state (P1, V1) to (P², V²) by two different processes, the quantity which will remain same is:

  • ΔQ
  • ΔW
  • ΔQ + ΔW
  • ΔQ - ΔW

  • 2. 
    Directions: The following question has four choices out of which ONLY ONE is correct.
    Which of the following is incorrect regarding the first law of thermodynamics? A. It is not applicable to any cyclic process B. It is a restatement of the principle of conservation of energy C. It introduces the concept of the internal energy D. It introduces the concept of the entropy

  • A and D
  • B and C
  • C and A
  • A and B

  • 3. 
    Directions: The following question has four choices out of which ONLY ONE is correct.
    In a thermodynamic process, pressure of a fixed mass of the gas is changed in such a manner that the gas molecules give out 30 J of heat. Also, 10 J of work is done on the gas. If the internal energy of the gas was 40 J, what will be the final internal energy?

  • 20 J
  • -20 J
  • 80 J
  • zero

  • 4. 
    Directions: The following question has four choices out of which ONLY ONE is correct.
    A Carnots engine works as a refrigerator between 250 K and 300 K. If it receives 750 calories of heat from the reservoir at the lower temperature, the amount of heat rejected at the higher temperature is __________.

  • 900 cal
  • 625 cal
  • 750 cal
  • 1000 cal

  • 5. 
    Directions: The following question has four choices out of which ONLY ONE is correct.
    In a thermodynamic process, pressure of a fixed mass of the gas is changed in such a manner that the gas molecules give out 30 J of heat. Also, 10 J of work is done on the gas. If the internal energy of the gas was 40 J, what will be the final internal energy?

  • 20 J
  • −20 J
  • 80 J
  • zero

  • 6. 
    Directions: The following question has four choices out of which ONLY ONE is correct.
    A thermodynamical system is changed from state (P1, V1) to (P², V²) by two different processes, the quantity which will remain same is:

  • ΔQ
  • ΔW
  • ΔQ + ΔW
  • ΔQ - ΔW

  • 7. 
    The temperatures of inside and outside of a refrigerator are 273 K and 303 K respectively. Assuming, that the refrigerator cycle is reversible, for every joule of work done, the heat delivered to the surrounding will be nearly:

  • 10 J
  • 20 J
  • 30 J
  • 50 J

  • 8. 
    An engine has an efficiency of 1/6. When the temperature of sink is reduced by 62°C, its efficiency is doubled. Temperature of the source is:

  • 124°C
  • 37°C
  • 62°C
  • 99°C

  • 9. 
    A black body at a temperature of 227°C radiates heat at the rate of 20 cal m-2s-1. When its temperature rises to 727°C, the heat radiated will be

  • 40 units
  • 160 units
  • 320 units
  • 640 units

  • 10. 
    At a given volume and temperature, the pressure of a gas

  • varies inversely as its mass
  • varies inversely as the square of its mass
  • varies linearly as its mass
  • is independent of its mass
Report Question
warning
Practice More On Thermodynamics
Quiz 1 Quiz 2
access_time
  Time