Correct : A. melting point rises slightly and boiling point drops markedly
2. At very low temperature, the melting and boiling temperatures become equal. This temperature is
Correct : B. 273.16°K
3. The critical pressure at which latent heat of vaporisation is zero is
Correct : A. 225.65 kgf/cm2
4. The latent heat of steam at pressures greater than atmospheric in comparison to latent heat at atmospheric pressure is
Correct : A. less
5. The saturation temperature of steam with increase in pressure increases
Correct : B. rapidly first and then slowly
6. Heating of dry steam above saturation temperature is known as
Correct : B. superheating
7. Superheating of steam is done at
Correct : C. constant pressure
8. Sublimation region is the region where
Correct : A. solid and vapour phases are in equi-librium
9. One kg of steam sample contains 0.8 kg dry steam; it's dryness fraction is
Correct : B. 0.8
10. If a steam sample is nearly in dry condition, then its dryness fraction can be most accurately determined by
Correct : A. throttling calorimeter
11. On Mollier chart, flow through turbine is represented by
Correct : B. vertical straight line
12. A wet vapour can be completely specified by
Correct : D. pressure and dryness fraction.
13. On Millier chart, the constant pressure lines
Correct : A. diverge from left to right
14. On Mollier chart, free expansion, or throttling process from high pressure to atmosphere is represented by
Correct : A. horizontal straight line
15. The dry saturated steam at very low pressure, (5-10 kg/cm2) when throttled to atmosphere will become
Correct : B. superheated
16. The dry saturated steam at very high pressure (150-200 kg/cm2) when throttled to atmosphere will become
Correct : A. wet
17. In a throttling process
Correct : C. steam enthalpy remains constant
18. In a throttling process
Correct : D. none of the above.
19. The latent heat of steam with increase of pressure
Correct : C. decreases
20. In an experiment to determine dryness fraction of steam, the mass of water separated was 1.2 kg in 15 minutes and the mass of steam passed out in same time was 4.8 kg. Dryness fraction is
Correct : D. 80%
21. Heating wet steam at constant temperature is heating it at constant
Correct : B. pressure
22. The state of vapour under saturation condition is described by
Correct : D. pressure and dryness fraction
23. The increase in pressure
Correct : B. raises the boiling point of a liquid
24. What is a pure substance?
Correct : B. a substance with constant chemical composition throughout its mass
25. A pure substance exists in
Correct : D. all of the above
26. Total heat of a substance is also known as
Correct : D. enthalpy
27. Equivalent evaporation of water is the evaporation "for a feed water supply at 100°C
Correct : A. and its corresponding conversion into dry saturated steam at 100°C and 1.033 kg/cm2
28. Cochran boiler is a
Correct : D. vertical fire tube boiler
29. Lancashire 'boiler is a
Correct : A. stationary fire tube boiler
30. The diameter of Cornish boiler is of the order of
Correct : A. 1-2 m
31. The lenght of Cornish boiler is of the order of
Correct : C. 5-7.5 m
32. The diameter of fire tube of Cornish boiler compared to its shell is
Correct : A. one half
33. Water tube boilers are those in which
Correct : C. work is done during adiabatic expansion
34. Lancashire boiler is of
Correct : D. all of the above.
35. Fire tube boilers are those in which
Correct : A. flue gases pass through tubes and water around it
36. The number of flue tubes in Lancashire boiler is
Correct : C. two
37. Which of the following is a water tube boiler
Correct : D. Babcock and Wilcox boiler
38. The diameter of cylindrical shell of the Lancashire boiler is of the order of
Correct : D. 1.75 to 2.75 m
39. A packaged boiler is one in which various parts like firing equipment, fans, feed pumps and automatic controls are
Correct : B. supplied mounted on a single base
40. The diameter of internal flue tubes in a Lancashire boiler compared to its shell is
Correct : D. two-fifth.
41. The water tubes in a babcock and wilcox boiler are
Correct : C. inclined
42. A boiler in India should conform to safety regulations of
Correct : D. IBR
43. The difference between cornish boiler and lancashire boiler is that
Correct : C. former contains one fire tube and latter contains two fire tubes
44. A fusible plug is fitted in small boilers in order to
Correct : C. extinguish fire if water level in the boiler falls below alarming limit
45. The fusible plug in small boilers is located
Correct : D. over the combustion chamber
46. Fusible plug for boilers is made of fusible metal containing tin, lead, and
Correct : A. bismuth
47. The ratio of heat utilised to produce steam and the heat liberated in furnace is known as
Correct : D. boiler efficiency.
48. It is required to produce large amount of steam at low pressure. Which boiler should be used ?
Correct : C. lancashire boiler
49. Size of boiler tubes is specified by
Correct : C. outside diameter and thickness
50. The heat loss in a boiler takes place in the form of
Correct : D. all of the above.
51. The diameter of fire tubes in Cochran boiler is of the order of
Correct : B. 6 Cm
52. In a recuperative air preheater, the heat is transferred
Correct : D. heat is tr
53. The function of injector used in small capacity boilers is to
Correct : C. pump water, similar to boiler feed pump
54. The maximum discharge through a chimney occurs when the height of chimney is
Correct : C. equal to the height of the hot gas column producing draught
55. The economiser is used in boilers to
Correct : A. increase thermal efficiency of boiler
56. An economiser in a boiler
Correct : C. decreases fuel consumption
57. The safety valve on boiler drum compared to safety valve on superheater is set at
Correct : B. higher value
58. The capacity of induced draft fan compared to forced draft fan in a boiler is
Correct : B. more
59. Evaporative capacity of boiler is expressed as
Correct : D. kg of steam produced per kg of fuel fired
60. The condition of steam in boiler drum is always
Correct : B. wet
61. The balanced draft furnace is one using
Correct : B. induced draft fan and forced draft fan
62. Fire tube boilers are limited to a maximum design working pressure of
Correct : C. 17 kg/cm2
63. For the same diameter and thickness of tube, a water tube boiler compared to a fire tube boiler has
Correct : A. more heating surface
64. The feed check valve is used in order to
Correct : D. allow high pressure feed water to flow to drum and not allow reverse flow to take place
65. Equivalent evaporation is the amount of water evaporated in a boiler from and at
Correct : B. 100°C
66. The equivalent evaporation of a boiler is a measure to compare
Correct : D. any type of boilers operating under any conditions.
67. Steam nozzle converts
Correct : B. heat energy of steam into kinetic energy
68. A nozzle is designed for
Correct : D. maximum kinetic energy at the outlet
69. Ideal expansion of steam through a nozzle is considered
Correct : B. adiabatic
70. Presence of frictional effect during flow through the nozzle
Correct : A. reduces the exit velocity
71. Frictional losses in the nozzle
Correct : A. reduces the heat drop
72. While steam expands in turbines, theoretically the entropy
Correct : A. remains constant
73. Nozzle efficiency is defined as
Correct : B. ratio of useful heat drop to isentropic heat drop
74. When a nozzle operates with maximum mass flow, it is said to be
Correct : C. choked flow
75. For supersaturated flow in the nozzle, the discharge
Correct : A. increases
76. For the flow through the convergent and divergent nozzle, whole of friction loss is assumed
Correct : B. in the divergent portion
77. The presence of friction in the nozzle
Correct : A. increases the final dryness fraction of steam
78. When the back pressure of a nozzle is below the critical pressure, the nozzle is said to be
Correct : C. choked flow
79. Which ideal process is carried out at the turbine in vapour power cycle?
Correct : B. reversible adiabatic expansion
80. The steam turbines is a
Correct : C. rotodynamic machine
81. From inlet to exit of steam nozzle, the pressure
Correct : B. decreases
82. From inlet to exit of moving blades in case of impulse turbine, the pressure
Correct : C. remains constant
83. From inlet to exit of moving blades in case of a reaction turbine, the pressure
Correct : B. decreases
84. In an impulse turbine, steam expands
Correct : A. in the nozzle only
85. In a reaction turbine, steam expands
Correct : C. in the fixed and moving blades
86. A simple impulse turbine consists of
Correct : A. one set of nozzles and one set of moving blades
87. In a velocity-compounded impulse steam turbine, steam expands in
Correct : A. one set of nozzles only
88. In a pressure-compounded impulse steam turbine, steam expands in
Correct : A. nozzles and fixed blades only
89. In a pressure-compounded impulse steam turbine, pressure drop over each ring of moving blades
Correct : A. remains constant
90. In a pressure-compounded impulse steam turbine, as compared to velocity compounding, the number of stages is
Correct : B. more
91. The condensation of steam in a condenser takes place at
Correct : C. constant pressure and constant temperature
92. During condensation process, the temperature of the condensing fluid
Correct : A. remains constant
93. The function of a condenser in a steam power plant is
Correct : D. all of the above
94. In a high-level jet condenser, the condenser shell is installed at a height of
Correct : B. more than 10.33 m
95. The surface condensers are preferred in steam power plant, because
Correct : B. condensate can be reused
96. In evaporative condensers, the condensing of steam is achieved
Correct : C. by evaporation of some coolant
97. Dalton's law of partial pressure, applicable to condensers, states that
Correct : C. Pabs = Pa+ Psat
98. The absolute pressure in a condenser is given by
Correct : B. Pabs = Patm -Pvacuum
99. Air leakage into the condenser reduces
Correct : D. all of the above
100. The vacuum maintained in a condenser depends on