1. A definite area or space where some thermodynamic process takes place is known as
Correct : A. thermodynamic system
2. An open system is one in which
Correct : C. both the heat & work as well as mass of the working substance cross the boundary of the system
3. An isolated system
Correct : C. cannot transfer either energy or mass to or from the surroundings
4. Which of the following is an intensive property of a thermodynamic system
Correct : B. temperature
5. Which of the following is the extensive property of a thermodynamic system
Correct : B. volume
6. When two bodies are in thermal equilibrium with a third body they are also in thermal equilibrium with each other. This statement is called
Correct : A. zeroth law of thermodynamics
7. The temperature at which the volume of a gas becomes zero is called
Correct : B. absolute zero temperature
8. The value of one bar (in SI units) is equal to
Correct : D. 1??10⁵ n/m??
9. The absolute zero pressure will be
Correct : A. when molecular momentum of the systembecomes zero
10. Absolute zero temperature is taken as
Correct : A. -273°c
11. Which of the following is correct?
Correct : A. absolute pressure= guage pressure+ atmosphericpressure
12. The unit of energy in SI units is
Correct : A. joule (j)
13. One watt is equal to
Correct : A. 1 nm/s
14. One joule (J) is equal to
Correct : A. 1 nm
15. A series of operations, which take place in a certain order & restore the initial condition is known as
Correct : C. thermodynamic cycle
16. The condition for the reversibility of a cycle is
Correct : D. all of the above
17. According to kinetic theory of heat
Correct : D. at absolute zero there is absolutely no vibration ofmolecules
18. A system comprising a single phase is called a
Correct : D. homogeneous system
19. If all the variables of a stream are independent of time it is said to be in
Correct : A. steady flow
20. A control volume refers to
Correct : A. a fixed region in space
21. Internal energy of a perfect gas depends on
Correct : D. temperature only
22. Steady flow process requires that
Correct : A. conditions do not change with time at any point
23. The first law of thermodynamics for steady flow
Correct : A. accounts for all energy entering & leaving a controlvolume
24. Which of the following is not a property of the system
Correct : D. heat
25. The process or systems that do not involve heat are called
Correct : C. adiabatic processes
26. Which one of the following statements is correct?
Correct : B. density is an intensiveproperty
27. First law of thermodynamics deals with conservation of
Correct : C. energy
28. Which one of the following processes or systems does not involve heat
Correct : C. adiabatic processes
29. Thermodynamic equillibrium is completely defined by the specification of
Correct : D. all of the above
30. ………. Is not a property of the system
Correct : C. heat
31. In which of the following processes the external work done is not zero?
Correct : D. constant pressureprocess
32. The extension & compression of a helical spring is an example of
Correct : B. reversible process
33. In all irrevesible processes, the entropy of the system
Correct : C. increases
34. Temperature of a gas is produced due to which of the following?
Correct : C. kinetic energy of molecules
35. The same volume of all gases at same temperatureand pressure would represent their
Correct : D. molecular weights
36. First law of thermodynamics gives relationship between which of the following?
Correct : C. heat, work & properties of the system
37. The temperature in a process in which work is done by expanding a gas under adiabatic condition will
Correct : A. decrease
38. On which of the following laws measurement of temperature is based?
Correct : B. zeroth law of thermodynamics
39. The perpetual motion of the first kind is represented by which of the following?
Correct : A. a machine that continuously creates itsown energy
40. Which of the following statements regarding a perpetual motion machine is correct?
Correct : D. it is hypothetic machine whose operation would violate the laws of thermodynamics
41. Which of the following statements, regarding a property of system, is correct?
Correct : B. it is a point function
42. ……….. Is an intensive property
Correct : A. specific volume
43. A system is said to be in thermodynamic equilibrium if it is in
Correct : D. all of the above
44. The basis for measuring thermodynamic property of temperature is given by ……. Law of thermodynamics
Correct : A. zeroth
45. As differentials, heat & work would be described mathematically as
Correct : B. inexact
46. Which of the following is an open thermodynamic system?
Correct : C. centrifugal pump
47. ……… is a non-quasistatic process
Correct : A. free expansion of gas
48. Choose the correct statement
Correct : D. volume & entropy are extensive properties
49. The first law of thermodynamics defines
Correct : B. internal energy
50. A process becomes irreversible due to
Correct : D. friction in the system
51. The main cause of the irreversibility is
Correct : D. all of the above
52. An isentropic process is always
Correct : D. reversible & adiabatic
53. In the polytropic process equation pvⁿ = constant, if n is infinitely large, the process is termed as
Correct : A. constant volume
54. Second law of thermodynamics defines
Correct : D. entropy
55. For a reversible adiabatic process, the change in entropy is
Correct : A. zero
56. For any reversible process, the change in entropy of the system & surroundings is
Correct : A. zero
57. For any irreversible process the net entropy change is
Correct : B. positive
58. The processes of a Carnot cycle are
Correct : D. two isothermals & two isentropies
59. Isentropic flow is
Correct : C. reversible adiabatic flow
60. In a carnot engine, when the working substance gives heat to the sink
Correct : B. the temperature of the sink remains the same
61. If the temperature of the source is increased, the efficiency of the Carnot engine
Correct : B. increase
62. The efficiency of an ideal Carnot engine depends on
Correct : D. on the temperatures of both the source & the sink
63. In a reversible cycle, the entropy of the system
Correct : C. does not change
64. Kelvin-Plank's law deals with
Correct : D. conversion of heat intowork
65. Which of the following statements is correct according to Clausius statement of second law of thermodynamics?
Correct : B. it is impossible to transfer heat from a body at a lower temperature to a body at a higher temperature, without the aid of an external source
66. The property of a working substance which increases or decreases as the heat is supplied or removed in a reversible
manner is known as
Correct : C. entropy
67. The entropy may be expressed as a function of
Correct : A. pressure & temperature
68. The change of entropy when heat is absorbed by the gas is
Correct : A. positive
69. Which of the following statements is correct?
Correct : D. all of the above
70. In an irreversible process, there is a
Correct : A. loss of heat
71. The efficiency of the Carnot cycle may be increased by
Correct : D. decreasing the lowesttemperature
72. Which of the following is the correct statement?
Correct : A. all the reversible engines have the same efficiency
73. The reversible engines are
Correct : B. most efficient
74. Gases could have an infinite number of specific heats but only ……. Specific heats are defined
Correct : B. two
75. The area under the T-s (temperature - entropy) curve of any thermodynamic process represents
Correct : D. heat absorbed or rejected
76. Second law of thermodynamics defines
Correct : C. entropy
77. For storing a gas which one of the following types of compression will be ideal
Correct : D. isothermal
78. A process which can be stopped at any stage & reversed so that the system & the surroundings are exactly restored to their initial states is known as
Correct : C. reversible process
79. Which of the following is a reversible process?
Correct : D. extension &compression of a spring
80. Leaking of air from a punctured tube is an example of
Correct : C. throttling
81. To convert volumetric analysis to gravimetric analysis, the relative volume of each constituent of the flue gases is
Correct : C. multiplied by its molecular weight
82. a heat engine receives heat at the rate of 1500 kJ/min.& gives an output of 8.2 kW. Its thermal efficiency is equal to
Correct : C. 32.8%
83. An inventor claims that a new heat cycle will develop 0.4 kW for a heat addition of 32.5 kJ/mm. The temperature of heat source is 1990 K & that of sink is 850K. Is his claim true?
Correct : B. false
84. Consider the following statements: The definition of
1. temperature is due to zeroth law of thermodynamics
2. entropy is due to first law of thermodynamics
3. internal energy is due to second law of thermodynamics
4. reversibility is due to Kelvin-Planck's ststement of these statements
Correct : C. 1 alone is correct
85. A heat engine is supplied with 250 kJ/s of heat at a constant fixed temperature of 227°C. The heat is rejected at 27°C. The cycle is reversible, if the amount of heat rejected is
Correct : D. 150 kj/s
86. A Carnot engine receiving heat at 400K has an efficiency of 25%. The C.O.P. of a Carnot refrigerator working between the same temperature limits is
Correct : C. 3
87. If a heat enine gives an output of 3 kW when the input is 10,000 J/s, then the thermal efficiency of the engine will be
Correct : B. 30%
88. The fundamental unit of enthalpy is
Correct : C. ml??t ????
89. In a cyclic heat engine operating between a source temperature of 600°C & a sink temperature of 20°C, the least rate of heat rejection per kW net output of the engine is
Correct : B. 0.505 kw
90. In a reversible cycle, the source temperature is 227°C & the sink temperature is 27°C. The maximum available work for a heat input of 100 kJ will be
Correct : C. 40 kj
91. A heat engine using lake water at 12° C as source & the surrounding atmosphere at 2°C as sink executes 1080 cycles per min. If the amount of heat drawn per cycle is 57J, then the output of the engine will be
Correct : D. 36 w
92. One reversible heat engine operates between 1600 K & T₂ K & another reversible heat engine operates between T₂ K & 400 K. If both the engines have the temperature T₂ must be equal to
Correct : D. 800 k
93. An engine receives 15152 J/s of heat & produces 5 KW of power. The efficiency
of the engine is
Correct : A. 25%
94. Choose the correct statement
Correct : D. volume & entropy are extensive properties
95. The second law of thermodynamics defines
Correct : D. entropy
96. Which law of thermodynamics defines entropy
Correct : B. second
97. Which of the following processes is essentially irreversible
Correct : D. thrittling
98. A thermodynamic cycle operates between 400 K. & 290 K. 500 MJ/s of heat is added to the working substance. The power generated is
Correct : D. 137.5 mj
99. A reversible engine performing as engine has efficiency of 62.5%. If it is reversed to work as refrigerator its COP will be
Correct : C. 65%
100. A reversible engine performing as refrigerator has COP=33%. If the same machine operates as engine, its efficiency will be