Practice Quiz 22

Choose the best answer

  1. Which of the following is a correct statement.
    1. A cyclic process is a process where the pressure remains constant.
    2. For a cyclic process, the heat supplied to (lost by)
      a system is zero.
    3. For a cyclic process, the work done on (by) the
      system is zero.
    4. For a cyclic process, the change in the internal
      energy of the system is zero.
    5. In a PV diagram, the heat supplied to (lost by)
      the system is obtained as the area of the closed curve.
    Answer: D

  2. 10 J of work was done on a system of gas by the
    enviornment. If at the same time it gained 75 J of energy,
    calculate the change in its internal energy.
    1. -85 J
    2. 65 J
    3. 0 J
    4. 85 J
    5. -65 J
    Answer: D

  3. The internal energy of a system of gas changed from 300 J
    to 15 J while losing 550 J of heat energy. Calculate the work
    done by (on) the system.
    1. 0 J
    2. 265 J
    3. -265 J
    4. 835 J
    5. -835 J
    Answer: C

  4. The volume of a system of gas decreased from 65 L to 45 L
    under a pressure of 70 kPa while gaining 105 J
    of internal energy. Calculate the amount of
    supplied or lost.
    1. 0 J
    2. 1295 J
    3. -1505 J
    4. 1505 J
    5. -1295 J
    Answer: E

  5. In a cyclic process, a system of gas was supplied with
    100 J of heat energy. Which of the
    following is a correct statement?
    1. The change in its internal energy is zero.
    2. The internal energy of the system increased by 100 J.
    3. The change in internal energy or the work done
      can not be determined based on the given information.
    4. 100 J of work was done by the enviornment on the system
    5. The work done by (on) the sytem is zero.
    Answer: A

  6. The following is a PV dagram for a certain system of gas.



    Calculate the work done in taking the system from the point D( 2 L, 4 kPa)
    to the point B( 6 L, 2 kPa) along path DCB.
    1. 24 J
    2. -8 J
    3. -16 J
    4. 8 J
    5. 16 J
    Answer: E

  7. The following is a PV dagram for a certain system of gas.



    Calculate the heat supplied (lost) in taking the system from the
    point B( 6 L, 2 kPa) where its internal energy is 70 J
    to the point D( 2 L, 4 kPa), where its internal energy
    is 65 J, along path BAD.
    1. 3 J
    2. -13 J
    3. 11 J
    4. -17 J
    5. -21 J
    Answer: B

  8. The following is a PV dagram for a certain system of gas.



    Calculate the work done by (on) the system for the cyclic
    process ABCDA.
    1. 0 J
    2. 16 J
    3. -16
    4. -8 J
    5. 8 J
    Answer: D

  9. The following is a PV dagram for a certain system of gas.



    Calculate the heat supplied to (lost by) the system
    for the cyclic process ADCBA.
    1. 8 J
    2. 16 J
    3. 0 J
    4. -16 J
    5. -8 J
    Answer: A

  10. Nature tends to proceed in a direction
    1. that increases its Gibb's function (free energy).
    2. that lowers its enthaly.
    3. that lowers its entropy.
    4. that lowers its kinetic energy
    5. that increases its potential energy.
    Answer: B

  11. A heat engine absorbs 1300 J of energy
    from a hot reservior at a temperature of 310 �C
    and gives off 780 J of energy to a cold
    reservior at a temperature of 38 �C in a cyclic process.
    Calculate the amount of work done per cycle.
    1. 1690 J
    2. 910 J
    3. 2080 J
    4. 0
    5. 520 J
    Answer: E

  12. Calculate the change in entropy during the
    vaporization of 0.6 kg of water.(Latent
    heat of vaporization for water is 2.26e6 J ⁄ kg).
    1. 5907.336 J ⁄ �K
    2. 2049.771 J ⁄ �K
    3. 1136.837 J ⁄ �K
    4. 3635.389 J ⁄ �K
    5. 4135.769 J ⁄ �K
    Answer: D