3. The number of degrees of freedom in case of diatomic gases is
Correct : C. 5
4. Which of the following statement is correct?
Correct : A. Both heat and work are path functions
5. Identify the correct statement
Correct : A. All substances emit radiation the quality and quantity depends on the absolute temperature and properties of the material composing the radiating body
6. Which of the following changes during throttling process?
Correct : A. Pressure
7. "The molecular weights of all the perfect gases occupy the same volume under same conditions of pressure and temperature".
Correct : C. Avogadro's hypothesis
8. In which case the heat transferred from the air when compressed from 1.05 ata 15?C to 6.3 ata would be minimum?
Correct : A. Adiabatic
9. The specific heat of water
Correct : D. First decreases, reaches a minimum value and then increases
10. If during a process the entropy of a isolated system increases, the process is
Correct : C. Irreversible
11. The number of processes in a Rankine cycle is
Correct : A. Four
12. Ericsson cycle processes are
Correct : B. Two isothermals and two constant pressures
13. In a Joule cycle, the heat is rejected at
Correct : A. Constant pressure
14. Isentropic flow is
Correct : C. Change in entropy is zero
15. The triple point for carbondioxide is at about -56.7 C and about 5 atm, pressure. It means that
Correct : E. When solid CO2 is exposed to 1 atm pressure it begins to change directly to gas
16. In a reversible cycle, the entropy of the system
Correct : C. Does not change
17. The first law of thermodynamics, for steady flow
Correct : A. Accounts for all energy entering and leaving a control volume
18. The unit of universal gas constant is
Correct : B. erg/?K
19. Which of the following is not a characteristic of liquid air?
Correct : C. It will freeze mercury and ammonia
20. Which of the following relation does not hold good for a throttling process?
Correct : B. dS = 0
21. According to Amagat's law
Correct : A. the sum of the volume friction is unity
22. In the polytropic process pvn = Constant if n = 1 the process is termed as
Correct : C. Constant temperature
23. Otto cycle consists of the set of processes as
Correct : A. Two isentropics and two constant volumes
24. If the two specific heats of a gas are 0.237 and 0.169 respectively, the volume of 3 kg of air at 27?C under a pressure of 3 ata would be
Correct : C. 0.204 cu-m
25. Five people must be lifted in an elevator to a distance of 100 m. The work is found to be 341.2 kJ and the gravitational acceleration is 9.75 m/s2. The average mass per person is
Correct : C. 70 kg
26. A substance above critical temperature exists as
Correct : C. Gas
27. In the above problem work done is equal to
Correct : D. 80 kcal
28. In a boiler a fusible plug is located at the
Correct : E. bottom of fire tubes
29. For maximum specific output of a constant volume cycle
Correct : D. Temperature of the working fluid at the end of compression and expansion should be equal
30. A frictionless heat engine can be 100% efficient only if its exhaust temperature is
Correct : C. 0?K
31. In steam tables, the entropy is shown as zero for
Correct : A. saturated liquid at 0?C
32. When a gas is to be stored, the type of compression that would be ideal is
Correct : A. Isothermal
33. Diffusion is
Correct : D. Mixing of unlike fluids
34. In case the temperature of a hot body is increased by 50%, the amount of radiation emitted by it would increase by nearly
Correct : B. 500%
35. The efficiency of cycle would be
Correct : A. 66.7 percent
36. If the temperature of the sink is decreased, the efficiency of a Carnot engine
Correct : E. increases
37. When a gas is to be stored, the type of compression that would be ideal is
Correct : A. Isothermal
38. According to Lussac's law for perfect gases, the absolute pressure of given mass varies directly as
Correct : C. Absolute temperature in case the volume remains constant
39. Gibbs free energy G is given by
Correct : D. G = H - Ts
40. A sterling cycle consists of
Correct : D. Two isothermal and two constant volume processes
41. A reversible process requires that
Correct : B. There whould be no viscous or coulomb friction in the system
42. The area of pv diagram for a Carnot cycle represents
Correct : D. Work done
43. An adlabatic wall permits
Correct : B. No heat exchange
44. The melting point of ice
Correct : B. decreases with increase in atmospheric pressure
45. In an isothermal process change in internal energy
Correct : C. Remains constant
46. When two gases are not under the same conditions of temperature and pressure, upon mixing there will be
Correct : B. exchange of entropy between the two gases
47. The dew point temperature of humid air is
Correct : D. the temperature of air obtained on cooling it till saturation at constant pressure
48. Which one of the following is heterogeneous system
Correct : E. A mixture of ice, water and system.
49. The value of characteristic gas constant for carbon dioxide would be
Correct : A. 19.28 kg/metre/kg/?K
50. In case of centrifugal compressors the phenomenon of fixed mass flow rate in compressor regardless of pressure ratio is known as
Correct : A. Choking
51. The statement that the entropy of a pure substance in complete theromodynamic equilibrium becomes zero at the absolute zero of temperature is known as
Correct : B. Third law of thermodynamics
52. A Carnot refrigerator extracts 100 kcal of heat per minute from a cold room which is maintained at - 15?C and it is discharged to atmosphere at 30?C. The horse power required to run the unit would be
Correct : B. 1.5 to 2
53. The function of a distributor is
Correct : C. To time the spark
54. A petrol engine fuel that knocks at a low speed
Correct : D. will always knock at high speed
55. Which of the following does not use ambient air for propulsion?
Correct : A. Rocket
56. During constant pressure heating of a gas the following does not increase?
Correct : A. Pressure
57. A safety valve is used on boilers to
Correct : D. To release excess pressure
58. For an ideal gas the value of Joule Kelvin coefficient is
Correct : D. Zero
59. Which of the following cycle consists of two isothemal and two constant volume processes?
Correct : B. Stirling cycle
60. The statement that energy can be neigher created nor destroyed but only converted from one form to another, is known as
Correct : C. First law of theormodynamics
61. Avogadro's numbers is
Correct : C. 6.02486 x 1026 molecules/(k mol)
62. The triple point of a substance is the temperature and pressure at which
Correct : C. The solid, liquid and the gaseous phases are in equilibrium
63. During the boiling of a liquid, which of the following parameter increases?
Correct : C. Entropy
64. Economiser in the boiler heats the
Correct : C. Feed water
65. For a closed system, the difference between the heat added to the system and the work done by the system is equal to the change in
Correct : C. internal energy
66. The area inside the PV diagram for a diesel engine represents
Correct : B. work done
67. In case of ideal monoatomic gas, the ratio of specific heats Cp/Cv would be
Correct : B. 1.67
68. Least value of specific heat
Correct : D. Air
69. Triple point temperature and pressure for water are
Correct : C. 0.01?C and 0.006028 ata
70. The shape of the lid of manhole in a boiler is
Correct : B. Elliptical
71. The process in which the change in internal energy of a gas is equal to the work done is known as
Correct : A. adiabatic process
72. During an adiabatic expansion the increase in volume is associated with
Correct : A. Decrease in pressure and decrease in temperature
73. In six stage compression of air set for minimum work conditions
Correct : D. Temperature rise in the cylinders will be the same
74. The rate of discharge through the nozzle
Correct : C. increases
75. A wall 50 mm thick (thermal conductivity k = 40 W/m?C) has temperature difference on two surfaces of 100?C. What could probably change if the temperature difference of this wall drops to 100?C
Correct : D. Rate of heat flow drops to one tenth of the original
76. The specific heat at constant volume of solids obeys Deby's T3 law
Correct : D. at all temperatures
77. The temperature, in degrees celsius, at which the colsius scale reading is numerically half the Fahrenheit scale reading is
Correct : D. 160?C
78. A jar contains a mixture of oxygen and hydrogen gas in the ratio 1 : 5. The ratio of mean knetic energies of hydrogen and oxygen molecules is
Correct : C. 1 ; 1
79. For any irreversible process the net entropy change is
Correct : C. Positive
80. "Heat can flow from cold substance to hot substance with the aid of external work". Which of the following name is associated with the above statement?
Correct : B. Clausius
81. In which case the work done per kg of air compressed from 1.05 ata, 15?C to 6.3 ata is minimum
Correct : C. Isothermal
82. The statement that molecular weight of all gases occupy the same volume at NTP is known as
Correct : B. Avogadro's hypothesis
83. 1 atmospheric pressure is equal to
Correct : B. 1.033 kg/cm2
84. The relation of the vapour pressure to the enthalpy of vaporization is expressed in
Correct : A. Clausius Clapeyron equation
85. During throttling process
Correct : C. Enthalpy does not change
86. Which of the following is an extensive property?
Correct : E. Heat capacity
87. The charge in a Diesel engine consists of
Correct : D. Air
88. Which of the following is incorrect?
Correct : E. None of the above
89. One kg of water is evaporated from 6 kg of sea water containing 4% salt. The percentage of salt in the remaining solution will be
Correct : D. 4.80%
90. In case of real gases, Cp will be equal to Cv
Correct : C. at absolute zero
91. If a surface is elastically hit by N balls each of mass M, moving with same velocity V, the force on the surface will be
Correct : D. 2 MNV
92. Antifreeze chemicals are
Correct : A. Those which lower down the freezing points of liquids
93. A carburettor is used to supply
Correct : B. Petrol + air
94. In an adiabatic compression the decrease in volume is associated with
Correct : D. Increase in temperature and increase in pressure
95. A gas having adiabatic index y = 1.4 and atmic weight A will have molecular weight
Correct : C. Pulsejet
96. Identify the incorrect statement
Correct : E. None of the above
97. When a bicycle pump is operated slowly the process of compression will be nearly
Correct : B. Isothermal process
98. For water, boiling and melting point will concide at
Correct : D. 2730.16? K
99. 1 bar pressure is nearly equal to
Correct : D. 750 mm Hg
100. In a Carnot cycle the process which must be carried out at extremely slow speed is