Thermodynamics Questions and Answers Part-4

1. The differentials of point functions are
a) perfect differentials
b) exact differentials
c) all of the mentioned
d) none of the mentioned

Answer: c
Explanation: Change in thermodynamic property is independent of path and depends only on initial and final states of the system.

2. In the equation dV=(1/p)dW, (1/p) is known as
a) volume factor
b) pressure factor
c) differential factor
d) integration factor

Answer: d
Explanation: Used to convert inexact differential dW into exact differential dV.

3. Cyclic integral of a property is always
a) zero
b) one
c) infinite value
d) none of the mentioned

Answer: a
Explanation: The initial and final states of the system for a cyclic process are the same.

4. Constant pressure process is also known as
a) isopiestic process
b) isobaric process
c) all of the mentioned
d) none of the mentioned

Answer: c
Explanation: Isobaric and isopiestic means pressure being constant.

5. Work done in a quasi-static process
a) depends on the path followed
b) independent of the path followed
c) depends only on the initial and final states
d) none of the mentioned

Answer: a
Explanation: This is because work done is a path function.

6. Macroscopic properties p and V are significant only for
a) equilibrium states
b) non-equilibrium states
c) depends on the state
d) none of the mentioned

Answer: a
Explanation: This is true for at any intermediate point in the travel of piston.

7. In a cylinder, infinitesimal amount of work done by the gas on piston is given by
a) F*dl
b) p*a*dl
c) p*dV
d) all of the mentioned

Answer: d
Explanation: F=p*a and work equals force multiplied by displacement.

8. For a constant pressure process, work done is
a) zero
b) p*(V2-V1)
c) p1*V1*ln(V2/V1)
d) none of the mentioned

Answer: b
Explanation: Work done in a process is given by the area under p-dV graph.

9. For a constant volume process, work done is
a) zero
b) p*(V2-V1)
c) p1*V1*ln(V2/V1)
d) none of the mentioned

Answer: a
Explanation: Work done in a process is zero since volume remains constant.

10. For a process in which pV=C, work done is
a) zero
b) p*(V2-V1)
c) p1*V1*ln(V2/V1)
d) none of the mentioned

Answer: c
Explanation: Work done is given by integral of (p*dV) from V1 to V2.