A closed thermodynamic system is one in which:

There is no energy transfer but there is mass transfer

There is no energy or mass transfer across the boundary

There is no mass transfer but energy transfer exists

There is no energy transfer but there is mass transfer

Both energy and mass transfer exist

For which of the following situations, zeroth law of thermodynamics will not be applicable?

50 cc of water at 25°C is mixed with 150 cc of water at 25°C

500 cc of milk at 15°C is mixed with 100 cc of water at 15°C

5 kg of wet stream at 100°C is mixed with 50 kg of dry and saturated steam at 100°C

10 cc of water at 20°C is mixed with 10 cc of sulphuric acid at 20°C

Energy of a system is defined as:

path function and intensive property

path function and extensive property

point function and intensive property

point function and extensive property

Pick the correct statement regarding path function.

The differentials of path functions are exact differentials

The differentials of point functions are inexact differentials

The differentials of point functions & path functions are exact differentials.

The differentials of path functions are inexact differentials

The differentials of path functions are exact differentials

Intensive Property of a system is the one that

Depends on mass and on path followed

A PV diagram is shown in the figure with three isotherms at temperature T1, T2 and T3. Four processes are represented in the diagram and are identified as 1, 2, 3 & 4. Then the processes indicated in the diagram are

1 – Isobaric, 2 – Adiabatic, 3 – Isothermal & 4 - Isochoric

1 – Isothermal, 2 – Isobaric, 3 – Isochoric & 4 - Adiabatic

1 – Isochoric, 2 – Isothermal, 3 – Adiabatic & 4 - Isobaric

1 – Isobaric, 2 – Isothermal, 3 – Adiabatic & 4 - Isochoric

1 – Isobaric, 2 – Adiabatic, 3 – Isothermal & 4 - Isochoric

Control volume in a thermodynamic system refers to-

Mass that moves across the boundary

Transfer of energy across the boundary

Fixed region in space for thermodynamic study

Match items from groups I, II, III, IV and V.Group IGroup IIGroup IIIGroup IVGroup V When added to the system, isDifferentialFunctionPhenomenonE HeatG PositiveI ExactK PathM TransientF WorkH NegativeJ InexactL PointN Boundary

F – G - J - K – ME – G - I – K - N

E – G - I - K – MF – H - I – K - N

F – H - J - L – NE – H - I – L - M

E – G - J - K – NF – H - J – K – N

In a steady state steady flow process taking place in a device with a single inlet and a single outlet, the work done per unit mass flow rate is given by \(w = - \mathop \smallint \limits_{inlet}^{outlet} vdp\), where v is specific volume and p is the pressure. The expression for w given above

is incorrect; it must be \(w = \mathop \smallint \limits_{inlet}^{outlet} pdv\)

is valid only if the process is both reversible and adiabatic

is valid only if the process is both reversible and isothermal

is valid for any reversible process

is incorrect; it must be \(w = \mathop \smallint \limits_{inlet}^{outlet} pdv\)

A balloon containing an ideal gas is initially kept in an evacuated and insulated room. The balloon ruptures and the gas fills up the entire room. Which one of the following statements is TRUE at the end of above process ?

Both internal energy and enthalpy of the gas increase

The internal energy of the gas decreases from its initial value, but the enthalpy remains constant

The internal energy of the gas increases from its initial value, but the enthalpy remains constant

Both internal energy and enthalpy of the gas remain constant

Both internal energy and enthalpy of the gas increase

A thermodynamic property:

can have different values when the system is in a particular state

does not depend on the past history of the system

can have different values when the system is in a particular state

depends on the past history of the system

26 + Mcqs in Thermodynamics System And Processes in Thermodynamics Page 1 McqOptions

1.	A closed thermodynamic system is one in which:
A.	There is no energy or mass transfer across the boundary
B.	There is no mass transfer but energy transfer exists
C.	There is no energy transfer but there is mass transfer
D.	Both energy and mass transfer exist
Answer» C. There is no energy transfer but there is mass transfer

Discussion

2.	In an unknown temperature scale freezing point of water is 0°X and boiling point of water is 1000°X. The absolute zero in degree X is
A.	-2731.5
B.	2731.5
C.	0
D.	-273.15
Answer» B. 2731.5

Discussion

3.	Gauge pressure of air to which the ball must have been originally inflated so that it would equal 1 bar gauge at the stadium is:
A.	2.23 bar
B.	1.94 bar
C.	1.07 bar
D.	1.00 bar
Answer» D. 1.00 bar

Discussion

4.	For which of the following situations, zeroth law of thermodynamics will not be applicable?
A.	50 cc of water at 25°C is mixed with 150 cc of water at 25°C
B.	500 cc of milk at 15°C is mixed with 100 cc of water at 15°C
C.	5 kg of wet stream at 100°C is mixed with 50 kg of dry and saturated steam at 100°C
D.	10 cc of water at 20°C is mixed with 10 cc of sulphuric acid at 20°C
Answer» E.

Discussion

5.	2 moles of oxygen are mixed adiabatically with another 2 moles of oxygen in mixing chamber, so that the final total pressure and temperature of the mixture become same as those of the individual constituents at their initial states. The universal gas constant is given as R. The change in entropy due to mixing, per mole of oxygen, is given by
A.	– R ln2
B.	0
C.	R ln2
D.	R ln4
Answer» C. R ln2

Discussion

6.	In thermodynamics, a process in which the system undergoes a succession of equilibrium states is a1) Quasi-static process2) Reversible process3) Irreversible process4) Path independent process
A.	1 & 3
B.	1 & 2
C.	3 & 4
D.	2 & 4
Answer» C. 3 & 4

Discussion

7.	Energy of a system is defined as:
A.	path function and intensive property
B.	path function and extensive property
C.	point function and intensive property
D.	point function and extensive property
Answer» E.

Discussion

8.	In thermometry, the standard fixed point is:
A.	vapour point of water
B.	ice point of water
C.	boiling point of H2
D.	triple point of water
Answer» E.

Discussion

9.	In the polytropic process pvn = constant, if n = 1 the process will be at
A.	Constant volume
B.	Constant pressure
C.	Constant temperature
D.	Adiabatic
Answer» D. Adiabatic

Discussion

10.	Pick the correct statement regarding path function.
A.	The differentials of point functions are inexact differentials
B.	The differentials of point functions & path functions are exact differentials.
C.	The differentials of path functions are inexact differentials
D.	The differentials of path functions are exact differentials
Answer» D. The differentials of path functions are exact differentials

Discussion

11.	In an isentropic process, the pressure of a monoatomic ideal gas increases by 0.5%. The volume will decrease (in %) by (Take (0.995)0.625= 0.997):
A.	0.4
B.	0.3
C.	0.2
D.	0.1
Answer» C. 0.2

Discussion

12.	Intensive Property of a system is the one that
A.	Does not depend on mass
B.	Depends on mass
C.	Depends on path followed
D.	Depends on mass and on path followed
Answer» B. Depends on mass

Discussion

13.	A PV diagram is shown in the figure with three isotherms at temperature T1, T2 and T3. Four processes are represented in the diagram and are identified as 1, 2, 3 & 4. Then the processes indicated in the diagram are
A.	1 – Isothermal, 2 – Isobaric, 3 – Isochoric & 4 - Adiabatic
B.	1 – Isochoric, 2 – Isothermal, 3 – Adiabatic & 4 - Isobaric
C.	1 – Isobaric, 2 – Isothermal, 3 – Adiabatic & 4 - Isochoric
D.	1 – Isobaric, 2 – Adiabatic, 3 – Isothermal & 4 - Isochoric
Answer» D. 1 – Isobaric, 2 – Adiabatic, 3 – Isothermal & 4 - Isochoric

Discussion

14.	A mercury thermometer was first placed in melting ice and the length of mercury column was observed to be 10 mm; when it was placed in steam, the length of the column was 250 mm. When placed in tap water, the length of the column was 58 mm. The temperature of the tap water is
A.	24.2°C
B.	20°C
C.	38.4°C
D.	4.14°C
Answer» C. 38.4°C

Discussion

15.	In a shower mixer, cold water at 27 deg C, flowing at 5 kg/min is mixed with hot water at 77 deg C flowing at 15 kg/min. The exit temperature of the mixture is
A.	45.4 deg C
B.	64.5 deg C
C.	34.5 deg C
D.	68.4 deg C
Answer» C. 34.5 deg C

Discussion

16.	In a polytropic process, pvn = c, if n = 0, then the process is
A.	Isobaric
B.	Isochoric
C.	Isothermal
D.	Adiabatic
Answer» B. Isochoric

Discussion

17.	A thermometer works on the principle of
A.	Law of stable equilibrium
B.	Zeroth law of thermodynamics
C.	First law of thermodynamics
D.	Second law of thermodynamics
Answer» C. First law of thermodynamics

Discussion

18.	Air with initial condition of p1, v1 expands to final condition of p1/2, 3v1. The process is
A.	Hyperbolic
B.	Adiabatic
C.	Polytropic with n > 1
D.	Polytropic with n < 1
Answer» E.

Discussion

19.	Frictionless pendulum is an example of:
A.	Irreversible process
B.	Reversible process
C.	Internal combustion engine
D.	Heat engine
Answer» C. Internal combustion engine

Discussion

20.	Control volume in a thermodynamic system refers to-
A.	A specified mass in fluid flow
B.	Mass that moves across the boundary
C.	Transfer of energy across the boundary
D.	Fixed region in space for thermodynamic study
Answer» E.

Discussion

21.	Match items from groups I, II, III, IV and V.Group IGroup IIGroup IIIGroup IVGroup V When added to the system, isDifferentialFunctionPhenomenonE HeatG PositiveI ExactK PathM TransientF WorkH NegativeJ InexactL PointN Boundary
A.	F – G - J - K – ME – G - I – K - N
B.	E – G - I - K – MF – H - I – K - N
C.	F – H - J - L – NE – H - I – L - M
D.	E – G - J - K – NF – H - J – K – N
Answer» E.

Discussion

22.	In a steady state steady flow process taking place in a device with a single inlet and a single outlet, the work done per unit mass flow rate is given by \(w = - \mathop \smallint \limits_{inlet}^{outlet} vdp\), where v is specific volume and p is the pressure. The expression for w given above
A.	is valid only if the process is both reversible and adiabatic
B.	is valid only if the process is both reversible and isothermal
C.	is valid for any reversible process
D.	is incorrect; it must be \(w = \mathop \smallint \limits_{inlet}^{outlet} pdv\)
Answer» D. is incorrect; it must be \(w = \mathop \smallint \limits_{inlet}^{outlet} pdv\)

Discussion

23.	A body of mass 20 kg falls freely in vacuum. It has fallen through a vertical distance of 50 m. The gravitational acceleration may be assumed as 10 m/s2. What is the thermodynamic work done by the body?
A.	1000 Nm
B.	10 kJ
C.	0
D.	1 kNm
Answer» D. 1 kNm

Discussion

24.	A balloon containing an ideal gas is initially kept in an evacuated and insulated room. The balloon ruptures and the gas fills up the entire room. Which one of the following statements is TRUE at the end of above process ?
A.	The internal energy of the gas decreases from its initial value, but the enthalpy remains constant
B.	The internal energy of the gas increases from its initial value, but the enthalpy remains constant
C.	Both internal energy and enthalpy of the gas remain constant
D.	Both internal energy and enthalpy of the gas increase
Answer» D. Both internal energy and enthalpy of the gas increase

Discussion

25.	__________ Irreversibility is due to the friction in the system.
A.	Chemical
B.	Rotary
C.	Internal
D.	Frictional
Answer» D. Frictional

Discussion

26.	A thermodynamic property:
A.	depends on the path
B.	does not depend on the past history of the system
C.	can have different values when the system is in a particular state
D.	depends on the past history of the system
Answer» C. can have different values when the system is in a particular state

Discussion

Explore topic-wise MCQs in Thermodynamics.

A closed thermodynamic system is one in which:

In an unknown temperature scale freezing point of water is 0°X and boiling point of water is 1000°X. The absolute zero in degree X is

Gauge pressure of air to which the ball must have been originally inflated so that it would equal 1 bar gauge at the stadium is:

For which of the following situations, zeroth law of thermodynamics will not be applicable?

In thermodynamics, a process in which the system undergoes a succession of equilibrium states is a1) Quasi-static process2) Reversible process3) Irreversible process4) Path independent process

Energy of a system is defined as:

In thermometry, the standard fixed point is:

In the polytropic process pvn = constant, if n = 1 the process will be at

Pick the correct statement regarding path function.

In an isentropic process, the pressure of a monoatomic ideal gas increases by 0.5%. The volume will decrease (in %) by (Take (0.995)0.625= 0.997):

Intensive Property of a system is the one that

A PV diagram is shown in the figure with three isotherms at temperature T1, T2 and T3. Four processes are represented in the diagram and are identified as 1, 2, 3 & 4. Then the processes indicated in the diagram are

A mercury thermometer was first placed in melting ice and the length of mercury column was observed to be 10 mm; when it was placed in steam, the length of the column was 250 mm. When placed in tap water, the length of the column was 58 mm. The temperature of the tap water is

In a shower mixer, cold water at 27 deg C, flowing at 5 kg/min is mixed with hot water at 77 deg C flowing at 15 kg/min. The exit temperature of the mixture is

In a polytropic process, pvn = c, if n = 0, then the process is

A thermometer works on the principle of

Air with initial condition of p1, v1 expands to final condition of p1/2, 3v1. The process is

Frictionless pendulum is an example of:

Control volume in a thermodynamic system refers to-

Match items from groups I, II, III, IV and V.Group IGroup IIGroup IIIGroup IVGroup V When added to the system, isDifferentialFunctionPhenomenonE HeatG PositiveI ExactK PathM TransientF WorkH NegativeJ InexactL PointN Boundary

In a steady state steady flow process taking place in a device with a single inlet and a single outlet, the work done per unit mass flow rate is given by \(w = - \mathop \smallint \limits_{inlet}^{outlet} vdp\), where v is specific volume and p is the pressure. The expression for w given above

A body of mass 20 kg falls freely in vacuum. It has fallen through a vertical distance of 50 m. The gravitational acceleration may be assumed as 10 m/s2. What is the thermodynamic work done by the body?

A balloon containing an ideal gas is initially kept in an evacuated and insulated room. The balloon ruptures and the gas fills up the entire room. Which one of the following statements is TRUE at the end of above process ?

__________ Irreversibility is due to the friction in the system.

A thermodynamic property: