Steam Boilers, Engines, Nozzles and Turbines Multiple Choice Questions
1. The maximum heat loss is a boiler occurs due to
A. Moisture in fuel
B. Dry flue gases
C. Steam formation
D. Unburnt carbon
Answer: B
2. A single stage impulse turbine with a diameter of 1.2 m runs at 3000 r.p.m. If the blade speed ratio is 0.42, then the inlet velocity of steam will be
A. 79 m/s
B. 188 m/s
C. 450 m/s
D. 900 m/s
Answer: C
3. The actual vacuum in a condenser is equal to
A. Barometric pressure + actual pressure
B. Barometric pressure – actual pressure
C. Gauge pressure + atmospheric pressure
D. Gauge pressure – atmospheric pressure
Answer: B
4. Steam turbines are used for
A. Large marine propulsion
B. Electric power generation
C. Direct drive of fans, compressors, pumps
D. All of these
Answer: D
5. Locomotive boiler is of the following type
A. Multi tubular
B. Horizontal
C. Internally fired
D. All of the above
Answer: D
6. It is required to produce large amount of steam at low pressure. Which boiler should be used?
A. Pulverized fuel fired boiler
B. Cochran boiler
C. Lancashire boiler
D. Babcock and Wilcox boiler
Answer: C
7. Reheating of steam in a turbine
A. Increases the work-done through the turbine
B. Increases the efficiency of the turbine
C. Reduces wear on the blades
D. All of these
Answer: D
8. The ratio of heat actually used in producing the steam to the heat liberated in the furnace, is known as
A. Equivalent evaporation
B. Factor of evaporation
C. Boiler efficiency
D. Power of a boiler
Answer: C
9. In designing air preheaters, the important design consideration is that
A. Approach temperature should be as low as possible
B. Handling and maintenance should be easier
C. Heat transfer area should be optimum
D. Stack gases should not be cooled to the dew point
Answer: D
10. A steam nozzle converts
A. Heat energy of steam into kinetic energy
B. Kinetic energy into heat energy of steam
C. Heat energy of steam into potential energy
D. Potential energy into heat energy of steam
Answer: A
11. The number of water level indicators in a boiler are generally __________ in number.
A. One
B. Two
C. Three
D. Four
Answer: B
12. The maximum discharge through a chimney occurs when the height of chimney is
A. Infinitely long
B. Around 200 meters
C. Equal to the height of the hot gas column producing draught
D. Outside temperature is very low
Answer: C
13. The factor of evaporation for all boilers is always
A. Equal to unity
B. Less than unity
C. Greater than unity
D. None of these
Answer: C
14. Water and sediment in fuel oil can be removed by
A. Heating the oil in the settling tanks
B. Cooling the oil in the settling tanks
C. Burning the oil
D. Suspension
Answer: B
15. For a Parson’s reaction turbine, if α₁ and α₂ are fixed blade angles at inlet and exit respectively and β₁ and β₂ are the moving blade angles at entrance and exit respectively, then
A. α₁ = α₂ and β₁ = β₂
B. α₁ = β₁ and α₂= β₂
C. α₁ < β₁ and α₂ > β₂
D. α₁ = β₂ and β₁ = α₂
Answer: B
16. In a reaction turbine when the degree of reaction is zero, then there is
A. No heat drop in moving blades
B. No heat drop in fixed blades
C. Maximum heat drop in moving blades
D. Maximum heat drop in fixed blades
Answer: A
17. A vessel into which the steam is exhausted and condensed after doing work in an engine cylinder or turbine is known as
A. Steam condenser
B. Steam boiler
C. Steam preheater
D. Economiser
Answer: A
18. The capacity of induced draft fan compared to forced draft fan in a boiler is
A. Same
B. More
C. Less
D. Less or more depending on size of boiler
Answer: B
19. The expansion of steam in a nozzle follows
A. Carnot cycle
B. Rankine cycle
C. Joule cycle
D. Stirling cycle
Answer: B
20. Which of the following compound steam engine requires a smaller flywheel?
A. Receiver type
B. Tandem type
C. Woolf type
D. All of these
Answer: A
21. The feed check valve is used in order to
A. Regulate flow of boiler water
B. Check level of water in boiler drum
C. Recirculate unwanted feed water
D. Allow high pressure feed water to flow to drum and not allow reverse flow to take place
Answer: D
22. The discharge of steam in a convergent-divergent nozzle __________ after the throat (i.e. in the divergent portion of the nozzle)
A. Remains constant
B. Decreases
C. Increases
D. None of these
Answer: A
23. An economiser _________ the steam raising capacity of a boiler.
A. Increases
B. Decreases
C. Has no effect on
D. None of these
Answer: A
24. 1 kg.m is equal to
A. 9.81 Joules
B. 102 Joules
C. 427 Joules
D. None of these
Answer: A
25. When the back pressure of a nozzle is below the designed value of pressure at exit of nozzle, the nozzle is said to be
A. Choked
B. Under-damping
C. Over-damping
D. None of these
Answer: B
26. The aim of a compound steam engine is
A. To reduce the ratio of expansion in each cylinder
B. To reduce the length of stroke
C. To reduce the temperature range in each cylinder
D. All of the above
Answer: D
27. At critical point, i.e. p=225.65 kg/cm², the latent enthalpy of vaporisation is
A. Maximum
B. Minimum
C. Zero
D. Depends on temperature also
Answer: C
28. Parson’s reaction turbine is a __________ reaction turbine.
A. 40 percent
B. 50 percent
C. 60 percent
D. 70 percent
Answer: B
29. A compound steam engine in which the high pressure and low pressure cylinders have common piston rod, is called
A. Receiver type compound engine
B. Tandem type compound engine
C. Woolf type compound engine
D. None of these
Answer: B
30. Lancashire boiler is a
A. Stationary fire tube boiler
B. Stationary water tube boiler
C. Water tube boiler with natural/forced circulation
D. Mobile fire tube boiler
Answer: A
31. In a reaction turbine, when steam flows through the fixed blades,
A. Pressure increases while velocity decreases
B. Pressure decreases while velocity increases
C. Pressure and velocity both decreases
D. Pressure and velocity both increases
Answer: B
32. The relative efficiency is defined as the
A. Ratio of thermal efficiency to Rankine efficiency
B. Ratio of brake power to the indicated power
C. Ratio of heat equivalent to indicated power to the energy supplied in steam
D. Product of thermal efficiency and Rankine efficiency
Answer: A
33. Which of the following is a fire tube boiler?
A. Locomotive boiler
B. Babcock and Wilcox boiler
C. Stirling boiler
D. All of the above
Answer: A
34. The purpose of governing in steam turbines is to
A. Maintain the speed of the turbine
B. Reduce the effective heat drop
C. Reheat the steam and improve its quality
D. Completely balance against end thrust
Answer: A
35. The performance of a boiler is measured by the
A. Amount of water evaporated per hour
B. Steam produced in kg/h
C. Steam produced in kg/kg of fuel burnt
D. All of these
Answer: D
36. Which of the following boilers is best suited to meet fluctuating demands?
A. Babcock and Wilcox
B. Locomotive
C. Lancashire
D. Cochran
Answer: B
37. The ratio of the work-done on the blades per kg of steam to the total energy supplied per stage per kg of steam is called
A. Blading efficiency
B. Nozzle efficiency
C. Stage efficiency
D. Mechanical efficiency
Answer: C
38. The artificial draught is produced by
A. Steam jet
B. Centrifugal fan
C. Chimney
D. BothA. andB.
Answer: D
39. With increase in load, radiant superheater has
A. Drooping characteristic
B. Linear characteristic
C. Rising characteristic
D. Flat characteristic
Answer: A
40. In a 50% reaction turbine stage, tangential component of absolute velocity at rotor inlet is 537 m/s and the blade velocity is 454 m/s. The power output in kW of steam will be
A. 260 kW
B. 282 kW
C. 296 kW
D. 302 kW
Answer: B
41. Which of the following statement indicates the difference between Cornish boiler and Lancashire boiler?
A. Cornish boiler is a water tube boiler whereas Lancashire boiler is a fire tube boiler
B. Cornish boiler is a fire tube boiler whereas Lancashire boiler is a water tube boiler
C. Cornish boiler has one flue tube whereas Lancashire boiler has two flue tubes
D. Cornish boiler has two flue tubes whereas Lancashire boiler has one flue tube
Answer: C
42. Primary air is the air used to
A. Provide air around burners for obtaining optimum combustion
B. Transport and dry the coal
C. Convert CO (formed in lower zone of furnace) into CO₂ at higher zone
D. Air delivered by forced draft fan
Answer: B
43. In an ideal impulse turbine, the
A. Absolute velocity at the inlet of moving blade is equal to that at the outlet
B. Relative velocity at the inlet of the moving blade is equal to that at the outlet
C. Axial velocity at inlet is equal to that at the outlet
D. Whirl velocity at inlet is equal to that at the outlet
Answer: B
44. A throttle governed steam engine develops 15 kW with 280 kg per hour of steam and 35 kW with 520 kg per hour of steam. The steam consumption in kg per hour when developing 20 kW will be nearly
A. 150 kg/h
B. 210 kg/h
C. 280 kg/h
D. 340 kg/h
Answer: D
45. Gradually increasing temperature of flue gases at inlet to chimney for given steam outputs is an indication of
A. Higher effectiveness of boiler
B. High calorific value coal being burnt
C. Fouling of heat transfer surfaces
D. Raising of steam temperature
Answer: C
46. The critical pressure ratio for initially superheated steam is __________ as compared to initially dry saturated steam.
A. More
B. Less
C. Same
D. None of these
Answer: B
47. A condenser in a steam power plant
A. Increases expansion ratio of steam
B. Reduces back pressure of steam
C. Reduces temperature of exhaust steam
D. All of these
Answer: D
48. An impulse turbine as compared to a reaction turbine, for a given power has _________ row of blades.
A. Equal
B. Less
C. More
D. None of these
Answer: C
49. For maximum discharge through a chimney, the condition is that height of hot gas column producing the draught should be
A. One-half the height of chimney
B. Equal to the height of chimney
C. Two times the height of chimney
D. Four times the height of chimney
Answer: B
50. The steam temperature with increase in load in case of a boiler fitted with radiation superheater
A. Increases
B. Decreases
C. Remain unaffected
D. First increases and then decreases
Answer: B
51. The rate of discharge through the nozzle __________ when the exit pressure is gradually reduced.
A. Remains same
B. Decreases
C. Increases
D. None of these
Answer: C
52. The object of producing draught in a boiler is
A. To provide an adequate supply of air for the fuel combustion
B. To exhaust the gases of combustion from the combustion chamber
C. To discharge the gases of combustion to the atmosphere through the chimney
D. All of the above
Answer: D
53. Feed water conditioning in thermal power plants in done to
A. Reduce hardness and for removal of solids
B. Increase efficiency of thermal power plant
C. Increase heat transfer rate
D. Increase steam parameters
Answer: A
54. A regenerative steam cycle renders
A. Increased work output per unit mass of steam
B. Decreased work output per unit mass of steam
C. Increased thermal efficiency
D. Decreased work output per unit mass of steam as well as increased thermal efficiency
Answer: D
55. The fire tubes in a Cochran boiler are
A. Horizontal
B. Vertical
C. Inclined
D. None of these
Answer: A
56. For water, at pressures below atmospheric;
A. Melting point rises slightly and boiling point drops markedly
B. Melting point rises markedly and boiling point drops markedly
C. Melting point drops slightly and boiling point drops markedly
D. Melting point drops slightly and boiling point drops slightly
Answer: A
57. The action of steam in a steam turbine is
A. Static
B. Dynamic
C. Static and dynamic
D. Neither static nor dynamic
Answer: B
58. The efficiency of the plant __________ with the mechanical draught.
A. Increases
B. Decreases
C. Remains constant
D. None of these
Answer: A
59. The latent heat of steam with increase of pressure
A. Remain same
B. Increases
C. Decreases
D. Behaves unpredictably
Answer: C
60. When the cross-section of a nozzle increases continuously from entrance to exit, it is called a
A. Divergent nozzle
B. Convergent nozzle
C. Convergent-divergent nozzle
D. None of these
Answer: A
61. The equivalent evaporation is defined as
A. The ratio of heat actually used in producing the steam to the heat liberated in the furnace
B. The amount of water evaporated or steam produced in kg per kg of fuel burnt
C. The amount of water evaporated from and at 100°C into dry and saturated steam
D. The evaporation of 15.653 kg of water per hour from and at 100°C
Answer: C
62. Steam engine operates on
A. Carnot cycle
B. Joule cycle
C. Stirling cycle
D. Brayton cycle
Answer: D
63. De-Laval turbines are mostly used
A. Where low speeds are required
B. For small power purposes and low speeds
C. For large power purposes
D. For small power purposes and high speeds
Answer: D
64. In a Tandem type compound engine, the high pressure and low pressure cylinders
A. Have common piston rod
B. Are set at 90°
C. Have separate piston rods
D. Are set in V-arrangement
Answer: A
65. Pick up the correct statement as regards Cornish boiler and Lancashire boiler
A. Cornish is fire tube and Lancashire is water tube
B. Cornish is water tube and Lancashire is fire tube
C. Cornish has two fire tubes and Lancashire has one
D. Lancashire has two fire tubes and Cornish has one
Answer: D
66. Blading efficiency is also known as
A. Stage efficiency
B. Diagram efficiency
C. Nozzle efficiency
D. None of these
Answer: B
67. In a single acting steam engine
A. The steam is admitted on one side of the piston and one working stroke is produced during each revolution of the crankshaft
B. The steam is admitted, in turn, on both sides of the piston and one working stroke is produced during each revolution of the crankshaft
C. The steam is admitted on one side of the piston and two working strokes are produced during each revolution of the crankshaft
D. The steam is admitted, in turn, on both sides of the piston and two working strokes are produced during each revolution of the crankshaft
Answer: A
68. Boiler H.P. is defined as the
A. Steam evaporation rate per kg of fuel fired
B. Work done in evaporating 1 kg of steam per hour from and at 100°C into dry saturated steam
C. The evaporation of 15.65 kg of water per hour from and at 100°C into dry saturated steam
D. Work done by 1 kg of steam at saturation condition
Answer: C
69. Steam turbines may be classified according to
A. Direction of steam flow
B. Number of stages
C. Mode of steam action
D. All of these
Answer: D
70. The fire tubes in a Locomotive boiler has __________ diameter.
A. 4.75 mm
B. 5.47 mm
C. 7.45 mm
D. 47.5 mm
Answer: D
71. The safety valve at superheater as compared to drum safety valve setting is set at
A. Higher value
B. Lower value
C. Same value
D. Any value
Answer: B
72. In a compound steam engine, the first stage of expansion is carried out in a high pressure cylinder whereas the last expansion is completed in low pressure cylinder. The diameter of high pressure cylinder is _________ the low pressure cylinder.
A. Equal to
B. Less than
C. More than
D. None of these
Answer: B
73. For combustion of a fuel, following is essential
A. Correct fuel air ratio
B. Proper ignition temperature
C. O₂ to support combustion
D. All the three above
Answer: D
74. In an impulse reaction turbine, the pressure drops gradually and continuously over
A. Fixed blades
B. Moving blades
C. Both fixed and moving blades
D. None of these
Answer: C
75. The efficiency of a boiler is defined as
A. Ratio of heat actually used in producing steam to the heat liberated in the furnace
B. Ratio of the mass of steam produced to the mass of total water supplied in a given time
C. Ratio of the heat liberated in the furnace to the heat actually used in producing steam
D. None of the above
Answer: A
76. The pressure compounded impulse turbine as compared to velocity compounded turbine require __________ number of stages.
A. Same
B. Less
C. More
D. None of these
Answer: C
77. The safety valve on boiler drum compared to safety valve on superheater is set at
A. Same value
B. Higher value
C. Lower value
D. Lower/higher depending on steam flow
Answer: B
78. Degree of reaction is defined as the ratio of
A. Heat drop in fixed blades to the heat drop in moving blades
B. Heat drop in moving blades to the heat drop in fixed blades
C. Heat drop in moving blades to the heat drop in fixed blades plus heat drop in moving blades
D. Heat drop in fixed blades plus heat drop in moving blades to the heat drop in moving blades
Answer: C
79. Which of the following statement is correct?
A. A horizontal steam engine requires less floor area than a vertical steam engine
B. The steam pressure in the cylinder is not allowed to fall below the atmospheric pressure
C. The compound steam engines are generally non-condensing steam engines
D. All of the above
Answer: B
80. A nozzle is said to be a convergent nozzle
A. When the cross-section of the nozzle increases continuously from entrance to exit
B. When the cross-section of the nozzle decreases continuously from entrance to exit
C. When the cross-section of the nozzle first decreases from entrance to throat and then increases from its throat to exit
D. None of the above
Answer: B
81. Which of the following statement is wrong?
A. Locomotive boiler is a water tube boiler
B. Water tube boilers are internally fired
C. Lamont boiler is a low pressure water tube boiler
D. All of the above
Answer: D
82. Film boiling occurs at
A. Very low pressure
B. Atmospheric pressures
C. Medium pressures
D. Very high pressures
Answer: D
83. The discharge is __________ at critical pressure.
A. Zero
B. Minimum
C. Maximum
D. None of these
Answer: C
84. An air preheater is installed
A. Before the economiser
B. Before the superheater
C. Between the economiser and chimney
D. None of these
Answer: D
85. Coke is produced by
A. Pulverizing coal in inert atmosphere
B. Heating wood in a limited supply of air at temperatures below 300°C
C. Strongly heating coal continuously for about 48 hours in the absence of air in a closed vessel
D. Enriching carbon in the coal
Answer: C
86. The variation of steam pressure in the nozzle depends upon
A. Velocity of steam
B. Specific volume of steam
C. Dryness fraction of steam
D. All of these
Answer: D
87. A safety valve mainly used with locomotive and marine boilers is
A. Lever safety valve
B. Dead weight safety valve
C. High steam and low water safety valve
D. Spring loaded safety valve
Answer: D
88. In a throttling process
A. Steam temperature remains constant
B. Steam pressure remains constant
C. Steam enthalpy remains constant
D. Steam entropy remains constant
Answer: C
89. De-Laval turbine is a
A. Simple impulse turbine
B. Simple reaction turbine
C. Impulse-reaction turbine
D. None of these
Answer: A
90. When steam after doing work in the cylinder passes into a condenser, the engine is said to be a
A. Slow speed engine
B. Vertical steam engine
C. Condensing steam engine
D. Non-condensing steam engine
Answer: C
91. Efficiency of Rankine cycle can be increased by
A. Decreasing initial steam pressure and temperature
B. Increasing exhaust pressure
C. Decreasing exhausts pressure
D. Increasing the expansion ratio
Answer: A
92. In an impulse turbine
A. The steam is expanded in nozzles only and there is a pressure drop and heat drop
B. The steam is expanded both in fixed and moving blades continuously
C. The steam is expanded in moving blades only
D. The pressure and temperature of steam remains constant
Answer: A
93. For the same diameter and thickness of tube, a water tube boiler has ________ heating surface as compared to fire tube boiler.
A. More
B. Less
C. Equal
D. None of these
Answer: A
94. Which of the following is a water tube boiler?
A. Locomotive boiler
B. Cochran boiler
C. Cornish boiler
D. Babcock and Wilcox boiler
Answer: D
95. In a reaction turbine
A. The steam is allowed to expand in the nozzle, where it gives a high velocity before it enters the moving blades
B. The expansion of steam takes place partly in the fixed blades and partly in the moving blades
C. The steam is expanded from a high pressure to a condenser pressure in one or more nozzles
D. The pressure and temperature of steam remains constant
Answer: B
96. The selection of type and size of a steam boiler depends upon
A. The power required and working pressure
B. The geographical position of the power house
C. The fuel and water available
D. All of the above
Answer: D
97. In natural circulation type boiler,
A. Heating takes place at bottom and the water supplied at bottom gets converted into the mixture of steam bubbles and hot water which rise to drum
B. Water is supplied in drum and through down comers located in atmospheric condition it passes to the water wall and rises to drum in the form of mixture of water and steam
C. Feed pump is employed to supplement natural circulation in water wall type furnace
D. Water is converted into steam in one. Pass without any recirculation
Answer: A
98. The maximum efficiency of a De-Laval turbine is (where α = Nozzle angle)
A. sin²α
B. cos²α
C. tan²α
D. cot²α
Answer: B
99. A _________ in a boiler is used to put off fire in the furnace of the boiler when the level of water in the boiler falls to an unsafe limit.
A. Blow off cock
B. Fusible plug
C. Stop valve
D. Safety valve
Answer: B
100. The ratio of heat utilized to produce steam and the heat liberated in furnace is known as
A. Boiler effectiveness
B. Boiler evaporative capacity
C. Factor of evaporation
D. Boiler efficiency
Answer: D
101. The blade friction in the impulse turbine reduces the velocity of steam by __________ while it passes over the blades.
A. 10 to 15%
B. 15 to 20%
C. 20 to 30%
D. 30 to 40%
Answer: A
102. For the same length of stroke and speed of crankshaft, the piston speed for a double acting steam engine is _________ the piston speed of single acting steam engine.
A. Equal to
B. Twice
C. Three times
D. Four times
Answer: B
103. The height of chimney in a power plant is governed by
A. The draft to be created
B. Limitation of construction facilities
C. Control of pollution
D. Quantity of flue gases to be handled
Answer: C
104. In impulse turbines, when friction is neglected, the relative velocity of steam at outlet tip of the blade is _________ the relative velocity of steam at inlet tip of the blade.
A. Equal to
B. Less than
C. Greater than
D. None of these
Answer: A
105. The fittings mounted on the boiler for its proper and safe functioning is a
A. Water level indicator
B. Pressure gauge
C. Safety valve
D. All of these
Answer: D
106. Presence of moisture in fuel oil would
A. Keep the burner tips cool
B. Aid in proper combustion
C. Because sputtering, possibly extinguishing flame
D. Clean the nozzles
Answer: C
107. In a steam condenser, the partial pressure of steam and air are 0.06 bar and 0.007 bar respectively. The condenser pressure is
A. 0.007 bar
B. 0.053 bar
C. 0.06 bar
D. 0.067 bar
Answer: D
108. Which is not correct statement about effect of sulphur in fuel?
A. It has heating value
B. It helps in electrostatic precipitation of ash in flue gases
C. It leads to corrosion of air heaters, ducting, etc. if flue gas exit temperature is low
D. It erodes furnace walls
Answer: D
109. The isentropic enthalpy drop in moving blade is two-third of the isentropic enthalpy drop in fixed blades of a turbine. The degree of reaction will be
A. 0.4
B. 0.56
C. 0.67
D. 1.67
Answer: A
110. A turbine is said to have an axial discharge when the steam leaves the blade tip at _________ to the direction of the blade motion.
A. 60°
B. 90°
C. 180°
D. 270°
Answer: B
111. The principal function of a stop valve is to
A. Control the flow of steam from the boiler to the main pipe and to shut off the steam completely when required
B. Empty the boiler when required and to discharge the mud, scale or sediments which are accumulated at the bottom of the boiler
C. Put off fire in the furnace of the boiler when the level of water in the boiler falls to an unsafe limit
D. Increase the temperature of saturated steam without raising its pressure
Answer: A
112. Fire tube boilers are limited to a maximum design working pressure of
A. 1 kg/cm
B. 6 kg/cm
C. 17 kg/cm²
D. 100 kg/cm²
Answer: C
113. The critical pressure ratio (p₂/p₁) is given by
A. (p₂/p₁) = [2/(n – 1)] n/(n + 1)
B. (p₂/p₁) = [2/(n + 1)] n/(n-1)
C. (p₂/p₁) = [(n – 1)/2] n + (1/n)
D. (p₂/p₁) = [(n + 1)/2] n – (1/n)
Answer: B
114. Water tube boilers are
A. Internally fired
B. Externally fired
C. Internally as well as externally fired
D. None of these
Answer: B
115. The bituminous coal is no caking if its carbon content is
A. 78-81%
B. 81-85%
C. 85-90%
D. 90-95%
Answer: A
116. The flow through a nozzle is regarded as
A. Constant volume flow
B. Constant pressure flow
C. Isothermal flow
D. Isentropic flow
Answer: D
117. A device used to increase the temperature of saturated steam without raising its pressure, is called
A. Blow off cock
B. Fusible plug
C. Superheater
D. Stop valve
Answer: C
118. Orsat meter is used for
A. Gravimetric analysis of the flue gases
B. Volumetric analysis of the flue gases
C. Mass flow of the flue gases
D. Measuring smoke density of flue gases
Answer: B
119. The Parsons’ reaction turbine has
A. Only moving blades
B. Only fixed blades
C. Identical fixed and moving blades
D. Fixed and moving blades of different shape
Answer: C
120. A single acting steam engine produces __________ power than that of double acting steam engine.
A. Equal
B. Half
C. Double
D. Four times
Answer: B
121. Which of the following substance will have same percentage in both proximate and ultimate analysis?
A. Ash
B. Volatile matter
C. Moisture
D. Hydrogen
Answer: A
122. The steam enters the nozzle at a
A. High pressure and a low velocity
B. High pressure and a high velocity
C. Low pressure and a low velocity
D. Low pressure and a high velocity
Answer: A
123. By compounding the expansion of steam in two or more cylinders, the length of stroke
A. Does not change
B. Increases
C. Decreases
D. None of these
Answer: C
124. The diameters of fire tubes and superheater tubes in locomotive boiler are
A. 47.5 mm, 130 mm
B. 32.5 mm, 180 mm
C. 65.5 mm, 210 mm
D. 24.5 mm, 65 mm
Answer: A
125. The effect of friction on the flow of steam through a nozzle is to
A. Decrease the mass flow rate and to increase the wetness of steam
B. Increase the mass flow rate and to increase the exit temperature
C. Decrease the mass flow rate and to decrease the wetness of steam
D. Increase the exit temperature without any effect on mass flow rate
Answer: C
126. Throttle governing of steam engines is a method of controlling the engine output by varying
A. Volume of intake steam
B. Pressure of intake steam
C. Temperature of intake steam
D. All of these
Answer: B
127. With increase in load, convection superheater has
A. Drooping characteristic
B. Linear characteristic
C. Rising characteristic
D. Flat characteristic
Answer: C
128. In order to reduce the rotor speed of an impulse turbine, the method employed is
A. Velocity compounding
B. Pressure compounding
C. Pressure-velocity compounding
D. All of these
Answer: D
129. In case of condensing steam engines, the pressure of steam in the cylinder during exhaust stroke is _________ the atmospheric pressure.
A. Equal to
B. Lower than
C. Higher than
D. None of these
Answer: C
130. Ultimate analysis of fuel is determination of percentage of
A. Carbon, hydrogen, nitrogen, sulphur, moisture
B. Fixed carbon, ash, volatile matter, moisture
C. Higher calorific value
D. Lower calorific value
Answer: A
131. Which of the following statement is correct?
A. The efficiency of steam turbines is greater than steam engines
B. A flywheel is a must for steam turbine
C. The turbine blades do not change the direction of steam issuing from the nozzle
D. The pressure of steam, in reaction turbines, is increased in fixed blades as well as in moving blades
Answer: A
132. By compounding the expansion of steam in two or more cylinders, the ratio of expansion
A. Does not change
B. Increases
C. Decreases
D. None of these
Answer: C
133. The proximate analysis of fuel lists
A. Various chemical constituents, carbon, hydrogen, oxygen etc, plus ash as percents by volume
B. Various chemical constituents, carbon, hydrogen, oxygen, etc, plus ash as percents by weight
C. Fuel constituents as percents by volume of moisture, volatile, fixed carbon and ash
D. Fuel constituents as percents by weight of moisture, volatile, fixed carbon and ash
Answer: D
134. A steam turbine, in which a part of the steam after partial expansion, is used for process heating and the remaining steam is further expanded for power generation, is known as
A. Back pressure turbine
B. Pass out turbine
C. Low pressure turbine
D. Impulse turbine
Answer: B
135. Willian’s law states that the steam consumption per hour provided with a throttled governor is proportional to (where I.P. = Indicated power)
A. 1/(I.P)
B. 1/(I.P)²
C. I.P.
D. (I.P.)²
Answer: C
136. Which is not the correct statement about moisture in coal?
A. Inherent moisture and surface moisture are different things
B. In some coals moisture may be present up to 40%
C. Some moisture in coal helps in better burning which is not possible with completely dry coal
D. It increases thermal efficiency
Answer: D
137. The friction present between the steam and the nozzle surfaces reduces the heat drop by
A. 10 to 15%
B. 15 to 25%
C. 25 to 40%
D. 40 to 60%
Answer: A
138. The draught in locomotive boilers is produced by a
A. Chimney
B. Centrifugal fan
C. Steam jet
D. None of these
Answer: C
139. Stoichiometric quantity of air is the
A. Air present in atmosphere at NTP conditions
B. Air required for complete combustion of fuel with no excess air
C. Air required for optimum combustion so as to have reasonable excess air
D. Air required to convert CO into CO₂
Answer: B
140. The impulse reaction turbine has its driving force
A. As an impulsive force
B. As a reaction force
C. Partly as an impulsive force and partly as a reaction force
D. None of the above
Answer: C
141. The average operating pressure of Benson boiler is
A. 100 bar
B. 150 bar
C. 200 bar
D. 250 bar
Answer: D
142. Pick up the wrong statement about critical condition of steam
A. Latent heat is zero
B. Liquid directly becomes steam
C. Specific volume of steam and liquid is same
D. This is the maximum pressure limit
Answer: D
143. In reaction turbines, the axial thrust is due to
A. Pressure drop across the rotor
B. Change in axial velocity
C. BothA. andB.
D. None of these
Answer: C
144. The draught produced by a steam jet issuing from a nozzle placed in the chimney is called
A. Induced steam jet draught
B. Chimney draught
C. Forced steam jet draught
D. None of these
Answer: A
145. A packaged boiler is one in which various parts like firing equipment, fans, feed pumps and automatic controls are
A. Supplied by same manufacturer loose and assembled at site
B. Supplied mounted on a single base
C. Purchased from several parties and packed together at site
D. Packaged boiler does not exist
Answer: B
146. The impulse turbine rotor efficiency will have a maximum value of 0.5 cos 2α, where α is the nozzle exit flow angle, if the
A. Blades are equiangular
B. Blade velocity coefficient is unity
C. Blades are equiangular and frictionless
D. Blade solidity is 0.65
Answer: C
147. Lancashire boiler is used where working pressure and power required are
A. Low
B. Moderate
C. High
D. None of these
Answer: B
148. Fusible plug for boilers is made of fusible metal containing tin, lead, and
A. Bismuth
B. Copper
C. Aluminium
D. Nickel
Answer: A
149. Which of the following statement is correct for steam turbines as compared to reciprocating steam engines?
A. A steam turbine develops higher speeds
B. The efficiency of steam turbine is higher
C. The steam consumption is less
D. All of these
Answer: D
150. Which of the following is not a boiler mounting?
A. Blow off cock
B. Feed check valve
C. Economiser
D. Fusible plug
Answer: C
151. In recuperative air preheaters, the heat is transferred
A. From a metal wall from one medium to another
B. From heating an intermediate material and then heating the air from this material
C. By direct mixing
D. Heat is transferred by bleeding some gases from furnace
Answer: A
152. The process of draining steam from the turbine, at certain points during its expansion and using this steam for heating the feed water in feed water heaters and then supplying it to the boiler is known as
A. Regenerative heating
B. Reheating of steam
C. Bleeding
D. None of these
Answer: C
153. Which of the following statement is wrong?
A. The mechanical draught reduces the height of chimney
B. The natural draught reduces the fuel consumption
C. A balanced draught is a combination of induced and forced draught
D. All of the above
Answer: B
154. Sulphur content of fuels is very important to the plant operators because it
A. Has high heating value
B. Retards electric precipitation
C. Promotes complete combustion
D. Has highly corrosive effect
Answer: D
155. Stage efficiency is also known as
A. Diagram efficiency
B. Nozzle efficiency
C. Gross efficiency
D. None of these
Answer: C
156. A device used to heat feed water by utilizing the heat in me exhaust flue gases before leaving through the chimney, is known as
A. Economizer
B. Fusible plug
C. Superheater
D. Stop valve
Answer: A
157. Which is not correct statement about the function of furnace?
A. To provide proper conditions for continuous complete combustion
B. Mix fuel with air and ignite
C. Separate ash from coal
D. Maintain heat supply to prepare and ignite the incoming fuel
Answer: C
158. In a nozzle, whole frictional loss is assumed to occur between
A. Inlet and throat
B. Inlet and outlet
C. Throat and exit
D. All of these
Answer: C
159. The working pressure range for a LaMont boiler is
A. 0.5 to 10 MN/m²
B. 1 to 15 MN/m²
C. 2.5 to 15 MN/m²
D. 3.5 to 20 MN/m²
Answer: D
160. The basic job of feed water treatment in boilers is to overcome the problem of
A. Corrosion
B. Scale
C. Carryover
D. All of the above
Answer: D
161. In a De-Laval nozzle expanding superheated steam from 10 bar to 0.1 bar, the pressure at the minimum cross-section (i. e. pressure at throat, p₂) will be
A. 3.3 bar
B. 5.46 bar
C. 8.2 bar
D. 9.9 bar
Answer: B
162. In a glass tube type water indicator for a boiler, one end of the tube is connected to water space and the other end is connected to
A. Water space also
B. Chimney
C. Steam space
D. Superheater
Answer: C
163. At very low temperature, the melting and boiling temperatures become equal. This temperature is
A. 373°K
B. 273.16°K
C. 303°K
D. 0°K
Answer: B
164. The ratio of the useful heat drop to the isentropic heat drop is called
A. Condenser efficiency
B. Nozzle efficiency
C. Boiler efficiency
D. Vacuum efficiency
Answer: B
165. The fire tubes in a Scotch marine boiler are
A. Horizontal
B. Vertical
C. Inclined
D. None of these
Answer: A
166. On Millier chart, the constant pressure lines
A. Diverge from left to right
B. Diverge from right to left
C. Are equally spaced throughout
D. First rise up and then fall
Answer: A
167. The reheat factor depends upon
A. Initial pressure and superheat
B. Exit pressure
C. Turbine stage efficiency
D. All of these
Answer: D
168. In a boiler, feed water supplied per hour is 205 kg while coal fired per hour is 23 kg. The net enthalpy rise per kg of water is 145 kJ. If the calorific valve of the coal is 2050 kJ/kg, then the boiler efficiency will be
A. 56 %
B. 63 %
C. 74 %
D. 78 %
Answer: B
169. The state of vapor under saturation condition is described by
A. Pressure alone
B. Temperature alone
C. Pressure and temperature
D. Pressure and dryness fraction
Answer: D
170. The diagram efficiency is the ratio of
A. Workdone on the blades to the energy supplied to the blades
B. Workdone on the blades per kg of steam to the total energy supplied per stage per kg of steam
C. Energy supplied to the blades per kg of steam to the total energy supplied per stage per kg of steam
D. None of the above
Answer: A
171. Locomotive boiler is a
A. Single tube, horizontal, internally fired and stationary boiler
B. Single tube, vertical, externally fired and stationary boiler
C. Multi-tubular, horizontal, internally fired and mobile boiler
D. Multi-tubular, horizontal, externally fired and stationary boiler
Answer: C
172. 100% efficiency of a thermal cycle cannot be achieved because of
A. Frictional losses
B. It is not possible to achieve 0°K temperature
C. Leakage
D. Non availability of ideal substance
Answer: B
173. In a velocity compounded impulse turbine, when steam flows through the second row of moving blades,
A. Velocity increases
B. Velocity decreases
C. Velocity remains constant
D. Pressure remains constant
Answer: B
174. Cut-off governing as compared to throttle governing is
A. Less efficient and less economical
B. Less efficient and more economical
C. More efficient and less economical
D. More efficient and more economical
Answer: D
175. Which of the following coals has the highest calorific value?
A. Anthracite coal
B. Bituminous coal
C. Lignite
D. Peat
Answer: A
176. In a Parson’s turbine stage, blade velocity is 320 m/s at the mean radius and rotor blade exit angle is 30°. For minimum kinetic energy of the steam leaving the stage, the steam velocity at the exit of the rotor will be
A. 160/3 m/s
B. 320/3 m/s
C. 640/3 m/s
D. 640 m/s
Answer: C
177. The main object of a boiler trial is
A. To determine the generating capacity of the boiler
B. To determine the thermal efficiency of the boiler when working at a definite pressure
C. To prepare heat balance sheet for the boiler
D. All of the above
Answer: D
178. Hard coke is used in
A. Cement industry
B. Thermal power plant
C. Blast furnace
D. Domestic use
Answer: C
179. The velocity of whirl at outlet for an axial discharge turbine is
A. Minimum
B. Maximum
C. Zero
D. None of these
Answer: C
180. The ratio of the volume at cut-off to the swept volume is called
A. Cut-off ratio
B. Expansion ratio
C. Clearance ratio
D. None of these
Answer: A
181. The effect of friction in the nozzle __________ dryness fraction of steam.
A. Has no effect on
B. Decreases
C. Increases
D. None of these
Answer: C
182. The overall efficiency of thermal power plant is
A. Boiler efficiency, turbine efficiency, generator efficiency
B. All the three above plus gas cycle efficiency
C. Carnot cycle efficiency
D. Regenerative cycle efficiency
Answer: A
183. A compound steam engine in which piston rods of high pressure and low pressure cylinders are attached to two different cranks set at 90° to each other, is called
A. Receiver type compound engine
B. Tandem type compound engine
C. Woolf type compound engine
D. BothA. andB.
Answer: A
184. In locomotives, the draught is produced by
A. Chimney
B. Induced draft fan
C. Both combinedA. andB.
D. Steam jet draught
Answer: D
185. The efficiency of an impulse turbine is maximum when (where Vb = Blade speed, V = Absolute velocity of steam entering the blade, and α = Nozzle angle)
A. Vb = 0.5 V cosα
B. Vb = V cosα
C. Vb = 0.5 V² cosα
D. Vb = V² cosα
Answer: A
186. The draught (in mm of water), for maximum discharge of flue gases through the chimney, is given by (where H = Height of the chimney in meters, and T1 = Absolute temperature of air outside the chimney in K)
A. T1 /88.25H
B. 88.25H/T1
C. T1 /176.5H
D. 176.5H/T1
Answer: D
187. The behavior of coal in a furnace is determined by
A. The content of sulphur
B. The content of ash and heating value
C. The proximate analysis
D. The exact analysis
Answer: C
188. The efficiency of a pressure-velocity compounded impulse turbine is __________ as compared to pressure compounded impulse turbine.
A. Same
B. Less
C. More
D. None of these
Answer: B
189. An economiser is generally placed between
A. Last superheater or reheater and air preheater
B. Induced draft fan and forced draft fan
C. Air preheater and chimney
D. None of the above
Answer: A
190. In order to obtain superheated steam, a superheater is added in an existing boiler. As as result, furnace vacuum will
A. Remain unaffected
B. Improve
C. Worsen
D. May improve/worsen depending on size
Answer: C
191. The maximum discharge of steam through a convergent-divergent nozzle depends upon
A. Area of nozzle at throat
B. Initial pressure and volume of steam
C. Final pressure of steam leaving the nozzle
D. BothA. andB.
Answer: D
192. In a boiler, the heat is lost
A. To dry flue gases
B. In moisture present in the fuel
C. To steam formed by combustion of hydrogen per kg of fuel
D. All of the above
Answer: D
193. The critical pressure at which latent heat of vaporisation is zero is
A. 225.65 kgf/ cm²
B. 273 kgf/ cm²
C. 100 kgf/ cm²
D. 1 kgf/ cm²
Answer: A
194. The effect of bleeding is that
A. It increases the thermodynamic efficiency of the turbine
B. Boiler is supplied with hot water
C. It decreases the power developed by the turbine
D. All of the above
Answer: D
195. Which of the following statement is correct for a compound steam engine?
A. The cost of the engine, for the same power and economy, is more than that of a simple steam engine
B. The forces in the working parts are increased as the forces are distributed over more parts
C. The ratio of expansion is reduced, thus reducing the length of stroke
D. The temperature range per cylinder is increased, with corresponding increase in condensation
Answer: C
196. One kg of steam sample contains 0.8 kg dry steam; Its dryness fraction is
A. 0.2
B. 0.8
C. 1.0
D. 0.6
Answer: B
197. The velocity of steam leaving the nozzle (V) is given by (where K = Nozzle coefficient or nozzle efficiency, and hd = Enthalpy or heat drop during expansion of steam in a nozzle)
A. V = 44.72 hd K
B. V = 44.72 K hd
C. V = 44.72 K hd
D. V = 44.72 K hd
Answer: C
198. The power of a boiler may be defined as
A. The ratio of heat actually used in producing the steam to the heat liberated in the furnace
B. The amount of water evaporated or steam produced in kg per kg of fuel burnt
C. The amount of water evaporated from and at 100° C into dry and saturated steam
D. The evaporation of 15.653 kg of water per hour from and at 100° C
Answer: B
199. Heating wet steam at constant temperature is heating it at constant
A. Volume
B. Pressure
C. Entropy
D. Enthalpy
Answer: B
200. The supersaturated flow of steam through a nozzle as compared to a stable flow, the available heat drop
A. Remains the same
B. Increases
C. Decreases
D. Is unpredictable
Answer: C
201. The velocity of flue gases (V) through the chimney under a static draught of (H’) metres is given by
A. V = 2g H’
B. V = 2g/H’
C. V = H’/2g
D. V = 2gH’
Answer: A
202. Efficiency of a thermal cycle increases by
A. Regeneration
B. Reheating of steam
C. BothA. andB.
D. Cooling of steam
Answer: C
203. Parson’s turbine is a
A. Simple impulse turbine
B. Simple reaction turbine
C. Impulse-reaction turbine
D. None of these
Answer: B
204. The diameter of a cylindrical shell of a Scotch marine boiler varies from
A. 1.5 to 2 m
B. 2.5 to 3.5 m
C. 3.5 to 4.5 m
D. None of these
Answer: B
205. The crown of the fire box is made hemispherical in order to
A. Give maximum space
B. Give maximum strength
C. Withstand pressure inside boiler
D. Resist intense heat in fire box
Answer: D
206. The velocity of steam at throat of the nozzle is __________ the velocity of sound.
A. Equal to
B. Less than
C. More than
D. None of these
Answer: A
207. The cylinder condensation or missing quantity may be reduced by
A. The efficient steam jacketing of the cylinder walls
B. Superheating the steam supplied to the engine cylinder
C. Keeping the expansion ratio small in each cylinder
D. All of the above
Answer: D
208. The Locomotive boiler has
A. 137 fire tubes and 44 superheated tubes
B. 147 fire tubes and 34 superheated tubes
C. 157 fire tubes and 24 superheated tubes
D. 167 fire tubes and 14 superheated tubes
Answer: C
209. Which of the following varieties of coals is mostly used in steam boilers?
A. Non-coking bituminous coal
B. Brown coal
C. Peat
D. None of the above
Answer: D
210. The compounding of turbines is done in order to
A. Reduce speed of rotor
B. Improve efficiency
C. Reduce exit losses
D. All of these
Answer: D
211. Which of the following is a fire tube boiler?
A. Lancashire boiler
B. Babcock and Wilcox boiler
C. Yarrow boiler
D. None of these
Answer: A
212. In forced recirculation type boiler,
A. Heating takes place at bottom and the water supplied at bottom gets converted into the mixture of steam bubbles and hot water which rise to drum
B. Water is supplied in drum and through down comers located in atmospheric condition it passes to the water wall and rises to drum in the form of mixture of water and steam
C. Feed pump is employed to supplement natural circulation in water wall type furnace
D. Water is converted into steam in one pass without any recirculation
Answer: C
213. When the nozzle operates with the maximum mass flow, the nozzle is said to be
A. Choked
B. Under-damping
C. Over-damping
D. None of these
Answer: A
214. The average value of diagram factor lies between
A. 0.2 to 0.5
B. 0.5 to 0.65
C. 0.65 to 0.9
D. 0.8 to 1.2
Answer: C
215. A safety valve in a locomotive starts leaking. The leaking medium will be
A. Water
B. Dry steam
C. Wet steam
D. Super heated steam
Answer: D
216. Which of the following statement is wrong?
A. The critical pressure gives the velocity of steam at the throat equal to the velocity of sound
B. The flow in the convergent portion of the nozzle is subsonic
C. The flow in the divergent portion of the nozzle is supersonic
D. To increase the velocity of steam above sonic velocity (supersonic) by expanding steam below the critical pressure, the divergent portion for the nozzle is not necessary
Answer: D
217. The ratio of the energy required to produce the artificial draught (expressed in meters head or J/kg of flue gas) to the mechanical equivalent of extra heat carried away per kg of flue gases due to natural draught, is known as
A. Efficiency of the boiler
B. Efficiency of the chimney
C. Efficiency of the fan
D. Power of the boiler
Answer: B
218. Which device is used in thermal power plants to reduce level of pollution?
A. Induced draft fan
B. Smoke meter
C. Chimney
D. Precipitator
Answer: D
219. The expansion of steam, as it flows over the blades in reaction turbine, represents
A. Isothermal process
B. Isentropic process
C. Throttling process
D. Free expansion process
Answer: B
220. Clearance ratio is the ratio of
A. Clearance volume to the swept volume
B. Clearance volume to the volume at cut-off
C. Volume at cut-off to the swept volume
D. Swept volume to the clearance volume
Answer: A
221. The ultimate analysis of fuel lists
A. Various chemical constituents, carbon, hydrogen, oxygen etc, plus ash as percents by volume
B. Various chemical constituents, carbon, hydrogen, oxygen, etc, plus ash as percents by weight
C. Fuel constituents as percents by volume of moisture, volatile, fixed carbon and ash
D. Fuel constituents as percents by weight of moisture, volatile, fixed carbon and ash
Answer: B
222. Which of the following statement is correct?
A. The expansion of steam in a nozzle follows Rankine cycle
B. The friction in the nozzle increases the dryness fraction of steam
C. The pressure of steam at throat is called critical pressure
D. All of the above
Answer: D
223. The heat balance sheet for the boiler shows the
A. Complete account of heat supplied by 1 kg of dry fuel and the heat consumed
B. Moisture present in the fuel
C. Steam formed by combustion of hydrogen per kg of fuel
D. All of the above
Answer: A
224. A supercritical boiler is one that operates above the pressure and temperature of following values
A. 100 kg/cm² and 540°C
B. 1 kg/cm² and 100°C
C. 218 kg/cm² abs and 373°C
D. 218 kg/cm² abs and 540°C
Answer: C
225. Curtis turbine is a
A. Simple reaction turbine
B. Velocity compounded turbine
C. Pressure compounded turbine
D. Pressure-velocity compounded turbine
Answer: D
226. The air pressure at the fuel bed is reduced below that of atmosphere by means of a fan placed at or near the bottom of the chimney to produce a draught. Such a draught is called
A. Natural draught
B. Induced draught
C. Forced draught
D. Balanced draught
Answer: B
227. The dry saturated steam at very low pressure, (510 kg/cm²) when throttled to atmosphere will become
A. Wet
B. Superheated
C. Remain dry saturated
D. Dry
Answer: B
228. The nozzle efficiency is the ratio of
A. Workdone on the blades to the energy supplied to the blades
B. Workdone on the blades per kg of steam to the total energy supplied per stage per kg of steam
C. Energy supplied to the blades per kg of steam to the total energy supplied per stage per kg of steam
D. None of the above
Answer: C
229. All steam engines work on
A. Zeroth law of thermodynamics
B. First law of thermodynamics
C. Second law of thermodynamics
D. None of these
Answer: C
230. The increase in pressure
A. Lowers the boiling point of a liquid
B. Raises the boiling point of a liquid
C. Does not affects the boiling point of a liquid
D. Reduces its volume
Answer: B
231. If the critical pressure ratio for steam is 0.546, then the steam is initially
A. Wet steam
B. Dry saturated steam
C. Superheated steam
D. None of these
Answer: C
232. The amount of water evaporated from feed water at _________ into dry and saturated steam at 100° C at normal atmospheric pressure is called equivalent evaporation from and at 100° C.
A. 0°C
B. 40°C
C. 60°C
D. 100°C
Answer: D
233. The high pressure boiler is one, which produces steam at a pressure more than
A. Atmospheric pressure
B. 5 kg/cm²
C. 10 kg/cm²
D. 7580 kg/cm²
Answer: D
234. The critical pressure ratio for gases is
A. 0.528
B. 0.546
C. 0.577
D. 0.582
Answer: A
235. Which of the following is correct? (Where pa = Actual mean effective pressure, pm = Theoretical mean effective pressure, and K = Diagram factor)
A. pa = pm/K
B. pa = pm × K
C. pa = K/pm
D. pa = pm + K
Answer: B
236. A stage, in reaction turbine, is represented by
A. Number of casing
B. Number of entries of steam
C. Number of exits of steam
D. Each row of blades
Answer: D
237. In a steam engine, superheated steam from the boiler is fed into the steam chest at a pressure of
A. 10 atmospheres
B. 20 atmospheres
C. 30 atmospheres
D. 40 atmospheres
Answer: B
238. The diameter of tubes for natural circulation boiler as compared to controlled circulation boilers is
A. More
B. Less
C. Same
D. Could be more or less depending on other factors
Answer: A
239. When the inlet pressure of steam is equal to the exit pressure, then
A. There is a pressure drop in the nozzle
B. Fluid flows through the nozzle
C. Pressure drops and fluid flows through the nozzle
D. There is no pressure drop and fluid does not flow through the nozzle
Answer: D
240. In water tube boilers
A. Water passes through the tubes which are surrounded by flames and hot gases
B. The flames and hot gases pass through the tubes which are surrounded by water
C. Forced circulation takes place
D. None of these
Answer: A
241. The temperature of flue gases at air heater outlet should be
A. 100°C
B. Above dew point temperature of flue gases
C. Below dew point temperature of flue gases
D. Less than wet bulb temperature of flue gases
Answer: B
242. The critical pressure ratio for initially wet steam is
A. 0.546
B. 0.577
C. 0.582
D. 0.601
Answer: C
243. The function of a cross-head is to guide motion of the _________ and to prevent it from bending.
A. Piston rod
B. Connecting rod
C. Eccentric rod
D. Valve rod
Answer: A
244. An economiser in a boiler
A. Increases steam pressure
B. Increases steam flow
C. Decreases fuel consumption
D. Decreases steam pressure
Answer: C
245. Multi-stage steam turbines are of the
A. Velocity compounded type
B. Reaction type
C. Pressure compounded type
D. All of these
Answer: D
246. A double acting steam engine with a cylinder diameter of 190 mm and a stroke of 300 mm has a cut-off of 0.35. The expansion ratio for this engine is nearly
A. 1.05
B. 2.86
C. 6.65
D. 10.05
Answer: B
247. Which is not correct statement about pulverized fuel firing?
A. High burning rate is possible
B. Heat release can be easily controlled
C. Fuel burns economically
D. It is the best technique for burning high ash content fuel having low fusion ash
Answer: D
248. The flow of steam is supersonic
A. At the entrance to the nozzle
B. At the throat of the nozzle
C. In the convergent portion of the nozzle
D. In the divergent portion of the nozzle
Answer: D
249. The diagram factor is the ratio of the
A. Area of the actual indicator diagram to the area of theoretical indicator diagram
B. Actual workdone per stroke to the theoretical workdone per stroke
C. Actual mean effective pressure to the theoretical mean effective pressure
D. Any one of the above
Answer: D
250. Relative percentage of heat absorbed through the heat transfer of
(i) Furnace water wall
(ii) Boiler tank
(iii) Superheater
(iv) Economizer
(v) Air-heater of a typical boiler of 200 MW capacity would be of the order of
A. 48 : 20 : 15 : 7 : 10
B. 10 : 7 : 15 : 20 : 48
C. 20 : 48 : 7 : 15 : 10
D. 7 : 15 : 20 : 10 : 48
Answer: A
251. The process of maintaining the speed of the turbine constant for various load conditions, is known as
A. Bleeding
B. Reheating
C. Governing
D. None of these
Answer: C
252. Expansion ratio is the ratio of
A. Swept volume to the volume at cut-off
B. Clearance volume to the swept volume
C. Volume at cut-off to the swept volume
D. Swept volume to the clearance volume
Answer: A
253. Superheating of steam is done at
A. Constant volume
B. Constant temperature
C. Constant pressure
D. Constant entropy
Answer: C
254. When the cross-section of a nozzle __________ continuously from entrance to exit, it is called a convergent nozzle.
A. Increases
B. Decreases
C. Remain same
D. None of these
Answer: B
255. In a receiver type compound engine, the high pressure and low pressure cylinders
A. Have common piston rod
B. Are set at 90°
C. Have separate piston rods
D. Are set in V-arrangement
Answer: C
256. Latent heat of dry steam at atmospheric pressure is equal to
A. 539 kcal/ kg
B. 539 BTU/ lb
C. 427 kcal/ kg
D. 100 kcal/ kg
Answer: A
257 The ratio of total useful heat drop to the total isentropic heat drop, is called
A. Stage efficiency
B. Internal efficiency
C. Rankine efficiency
D. None of these
Answer: B
258. The pressure of feed water has to be raised before its entry into the boiler. The pressure is raised by a device known as
A. Feed pump
B. Injector
C. Feed check valve
D. Pressure gauge
Answer: A
259. For burning 1 kg of carbon to CO as per chemically correct combustion, amount of air required is
A. 1 kg
B. 4/3 kg
C. 8/3 kg
D. 2 kg
Answer: B
260. A binary vapor plant consists of
A. Steam turbine
B. Steam condenser
C. Mercury boiler
D. All of these
Answer: D
261. The draught may be produced by a
A. Mechanical fan
B. Chimney
C. A steam jet
D. All of these
Answer: D
262. Which of the following is steam dial?
A. Non-coking bituminous coal
B. Brown coal
C. Pulverized coal
D. Coking bituminous coal
Answer: A
263. The maximum efficiency of a reaction turbine is
A. 2 sin²α/(1 + sin²α)
B. 2 cos²α/(1 + cos²α)
C. (1 + sin²α)/2 sin²α
D. (1 + cos²α)/2 cos²α
Answer: B
264. In order to compare the capacity of boilers, the feed water temperature and working pressure are taken as
A. 50°C and normal atmospheric pressure
B. 50°C and 1.1 bar pressure
C. 100°C and normal atmospheric pressure
D. 100°C and 1.1 bar pressure
Answer: C
265. In accelerated circulation type boiler
A. Heating takes place at bottom and the water supplied at bottom gets converted into the mixture of steam bubbles and hot water which rise to drum
B. Water is supplied in drum and through down comers located in atmospheric condition it passes to the water wall and rises to drum in the form of mixture of water and steam
C. Feed pump is employed to supplement natural circulation in water wall type furnace
D. Water is converted into steam in one pass without any recirculation
Answer: B
266. The pressure of steam __________ while flowing through a nozzle.
A. Increases
B. Decreases
C. Remains constant
D. None of these
Answer: B
267. The indicated thermal efficiency is defined as the
A. Ratio of thermal efficiency to the Rankine efficiency
B. Ratio of brake power to the indicated power
C. Ratio of heat equivalent to indicated power to the energy supplied in steam
D. Product of thermal efficiency and Rankine efficiency
Answer: C
268. The major axis of elliptical manholes on the shell should be provided
A. Longitudinally
B. Circumferentially
C. On dished end
D. Anywhere
Answer: B
269. In a reaction turbine, when steam flows through the moving blades,
A. Pressure increases while velocity decreases
B. Pressure decreases while velocity increases
C. Pressure and velocity both decreases
D. Pressure and velocity both increases
Answer: C
270. The device attached to the steam chest for preventing explosions due to excessive internal pressure of steam is called
A. Safety valve
B. Water level indicator
C. Pressure gauge
D. Fusible plug
Answer: A
271. The economiser is used in boilers to
A. Increase thermal efficiency of boiler
B. Economize on fuel
C. Extract heat from the exhaust flue gases
D. Increase flue gas temperature
Answer: A
272. The reheat factor is the ratio of the
A. Cumulative heat drop to the isentropic heat drop
B. Isentropic heat drop to the heat supplied
C. Total useful heat drop to the total isentropic heat drop
D. None of the above
Answer: A
273. Which of the following statement is correct?
A. A fire tube boiler occupies less space than a water tube boiler, for a given power
B. Steam at a high pressure and in large quantities can be produced with a simple vertical boiler
C. A simple vertical boiler has one fire tube
D. All of the above
Answer: C
274. The three “Ts” for good combustion are
A. Temperature, time, and turbulence
B. Total air, true fuel, and turbulence
C. Thorough mixing, total air and temperature
D. Total air, time, and temperature
Answer: A
275. The value of the reheat factor varies from
A. 1.02 to 1.06
B. 1.08 to 1.10
C. 1.2 to 1.6
D. 1.6 to 2
Answer: A
276. Cut-off governing of steam engines is a method of controlling the engine output by varying
A. Volume of intake steam
B. Pressure of intake steam
C. Temperature of intake steam
D. All of these
Answer: A
277. The size of a boiler drum in pulverized fuel fired boiler, as its size and capacity, (steam pressure and flow ratings) increase
A. Increases
B. Decreases
C. Remains unchanged
D. Increases/decreases depending on steam temperature requirements
Answer: B
278. A nozzle is said to be a divergent nozzle
A. When the cross-section of the nozzle increases continuously from entrance to exit
B. When the cross-section of the nozzle decreases continuously from entrance to exit
C. When the cross-section of the nozzle first decreases from entrance to throat and then increases from its throat to exit
D. None of the above
Answer: A
279. The theoretical indicator diagram of a simple steam engine is based upon the assumption that
A. There is no pressure drop due to condensation
B. Steam is admitted at boiler pressure and exhausted at condenser pressure
C. The expansion (or compression) of the steam is hyperbolic
D. All of the above
Answer: D
280. If partial pressure of air and steam be ‘pa’ and ‘ps’ respectively in a condenser, then according to Dalton’s law, the pressure in condenser is equal to
A. ps – pa
B. pa – ps
C. pa + ps
D. None of these
Answer: C
281. In turbines, the fluid undergoes a continuous steady flow process and the speed of flow is
A. Low
B. Very low
C. High
D. Very high
Answer: D
282. The high steam and low water safety valve is used to blow off steam when the
A. Steam pressure exceeds the working pressure
B. Water level in the boiler becomes too low
C. BothA. andB.
D. None of the above
Answer: C
283. On Mollier chart, free expansion, or throttling process from high pressure to atmosphere is represented by
A. Horizontal straight line
B. Vertical straight line
C. Straight inclined line
D. Curved line
Answer: A
284. The critical pressure gives the velocity of steam at the throat
A. Equal to the velocity of sound
B. Less than the velocity of sound
C. More than the velocity of sound
D. None of these
Answer: A
285. The high pressure and low pressure cylinders in a Woolf type compound engine are regarded as having cranks
A. 180° to each other
B. 90° to each other
C. 0° to each other
D. None of these
Answer: A
286. Mechanical equivalent of heat for 1 kcal or Joule’s equivalent is equal to
A. 421 kg.m
B. 421 kg.m
C. 539 kg.m
D. 102 kg.m
Answer: A
287. The effect of super-saturation is that the
A. Mass of the steam discharged increases
B. Entropy and specific volume of the steam increases
C. Exit velocity of steam reduces
D. All of these
Answer: D
288. The diameter of superheated tubes in a locomotive boiler is
A. 13 mm
B. 31 mm
C. 130 mm
D. 230 mm
Answer: C
289. The change in internal energy in steam engines equals to
A. Work done during the Rankine cycle
B. Work done during compression
C. Work done during adiabatic expansion
D. Change in enthalpy
Answer: A
290. The pressure velocity compounded impulse turbine allows a bigger pressure drop and hence __________ numbers of stages are required.
A. More
B. Less
C. Equal
D. None of these
Answer: B
291. In fire tube boilers
A. Water passes through the tubes which are surrounded by flames and hot gases
B. The flames and hot gases pass through the tubes which are surrounded by water
C. Forced circulation takes place
D. None of these
Answer: B
292. The shell diameter and length of locomotive boiler are
A. 1.5 m, 4 m
B. 1.5 m, 6 m
C. 1 m, 4 m
D. 2 m, 4 m
Answer: A
293. The ratio of the workdone on the blades to the energy supplied to the blades, is called
A. Blading efficiency
B. Nozzle efficiency
C. Gross or stage efficiency
D. Mechanical efficiency
Answer: A
294. The numbers of fire tubes in a Cochran boiler are
A. 75
B. 115
C. 165
D. 225
Answer: C
295. In forced circulation type boiler
A. Heating takes place at bottom and the water supplied at bottom gets converted into the mixture of steam bubbles and hot water which rise to drum
B. Water is supplied in drum and through down comers located in atmospheric condition it passes to the water wall and rises to drum in the form of mixture of water and steam
C. Feed pump is employed to supplement natural circulation in water wall type furnace
D. Water is converted into steam in one pass without any recirculation
Answer: D
296. The critical pressure ratio for initially dry saturated steam is
A. 0.546
B. 0.577
C. 0.582
D. 0.601
Answer: B
297. In cross compounding, the cylinders are arranged
A. Side by side and each cylinder has common piston, connecting rod and crank
B. Side by side and each cylinder has separate piston, connecting rod and crank
C. At 90° and each cylinder has common piston, connecting rod and crank
D. At 90° and each cylinder has separate piston, connecting rod and crank
Answer: B
298. Vacuum for reciprocating steam engines compared to steam turbines is
A. More
B. Equal
C. Less
D. Could be more or less depending on the size of plant
Answer: C
299. In a nozzle, the effect of super-saturation is to
A. Decrease dryness fraction of steam
B. Decrease specific volume of steam
C. Increase the entropy
D. Increase the heat drop
Answer: C
300. The cylindrical shell of a Lancashire boiler has diameter from
A. 1 to 2 m
B. 1.25 to 2.25 m
C. 1.5 to 2.5 m
D. 1.75 to 2.75 m
Answer: D
301. Pour point of fuel oil is the
A. Lowest temperature at which oil will flow under set condition
B. Storage temperature
C. Temperature at which fuel is pumped through burners
D. Temperature at which oil is transported
Answer: A
302. The steam leaves the nozzle at a
A. High pressure and a low velocity
B. High pressure and a high velocity
C. Low pressure and a low velocity
D. Low pressure and a high velocity
Answer: D
303. A condenser where circulating water flows through tubes which are surrounded by steam, in known as
A. Surface condenser
B. Jet condenser
C. Barometric condenser
D. Evaporative condenser
Answer: A
304. Maximum energy loss in a boiler occurs due to
A. Unburnt carbon in ash
B. Incomplete combustion
C. Ash content
D. Flue gases
Answer: D
305. The friction in the nozzle __________ exit velocity of steam.
A. Has no effect on
B. Decreases
C. Increases
D. None of these
Answer: B
306. The function of an eccentric rod is
A. To provide reciprocating motion to the slide valve
B. To convert reciprocating motion of the piston into rotary motion of the crank
C. To convert rotary motion of the crankshaft into to and fro motion of the valve rod
D. To provide simple harmonic motion to the D-slide valve
Answer: C
307. In water wall furnace, the heat is transferred to the water walls by
A. Convection
B. Radiation
C. Conduction
D. Radiation and conduction
Answer: B
308. The efficiency of reaction turbine is maximum when (where α = Angle made by the absolute velocity ‘V’ at inlet)
A. Vb = 0.5 V cosα
B. Vb = V cos α
C. Vb = 0.5 V² cosα
D. Vb = V² cos α
Answer: B
309. When the speed of the crankshaft is between 100 r.p.m. and 250 r.p.m., the engine said to be a
A. Slow speed engine
B. Medium speed steam engine
C. High speed steam engine
D. None of these
Answer: B
310. The latent heat of steam at pressures greater than atmospheric in comparison to latent heat at atmospheric pressure is
A. Less
B. More
C. Equal
D. May be less or more depending on temperature
Answer: A
311. The efficiency of steam turbines may be improved by
A. Reheating of steam
B. Regenerative feed heating
C. Binary vapor plant
D. Any one of these
Answer: D
312. In a uniflow engine
A. Steam enters and exhausts through the same port
B. Steam enters at one end and exhausts at the centre
C. Steam enters at the centre and exhausts at the other end
D. None of the above
Answer: B
313. In an experiment to determine dryness fraction of steam, the mass of water separated was 1.2 kg in 15 mts. and the mass of steam passed out in same time was 4.8 kg. Dryness fraction is
A. 40 %
B. 25 %
C. 50 %
D. 80 %
Answer: D
314. The critical pressure ratio is given by (where p₁ = Initial pressure of steam, and p₂ = Pressure of steam at throat or critical pressure)
A. p₁. p₂
B. p₁/p₂
C. p₂/p₁
D. p₁ + p₂
Answer: C
315. Which of the following is a water tube boiler?
A. Lancashire boiler
B. Babcock and Wilcox boiler
C. Locomotive boiler
D. Cochran boiler
Answer: B
316. The diameter of Cornish boiler is of the order of
A. 12 m
B. 1.52.5 m
C. 23 m
D. 2.53.5 m
Answer: A
317. The stage efficiency (ηS) is given by (where ηB = Blading efficiency, and ηN = Nozzle efficiency)
A. ηS = ηB × ηN
B. ηS = ηB / ηN
C. ηS = ηN / ηB
D. None of these
Answer: A
318. The high pressure and low pressure cylinders in a Tandem type compound engine are regarded as having cranks
A. 180° to each other
B. 90° to each other
C. 0° to each other
D. None of these
Answer: C
319. The water tubes in a Babcock and Wilcox boiler are
A. Horizontal
B. Vertical
C. Inclined
D. Horizontal and inclined
Answer: C
320. In an impulse turbine, steam expands
A. Wholly in blades
B. Wholly in nozzle
C. Partly in the nozzle and partly in blades
D. None of these
Answer: B
321. There is always some steam left in the clearance space from the previous stroke. This steam left in the clearance space is called
A. Wet steam
B. Saturated steam
C. Superheated steam
D. Cushion steam
Answer: D
322. In which of the following boilers, the draught in furnace is increased by utilising exhaust steam from engine
A. Lancashire boiler
B. Locomotive boiler
C. Babcock and Wilcox boiler
D. Benson boiler
Answer: B
323. De-Laval turbine is a
A. Single rotor impulse turbine
B. Multi-rotor impulse turbine
C. Impulse reaction turbine
D. None of these
Answer: A
324. An air preheater
A. Increases evaporative capacity of the boiler
B. Increases the efficiency of the boiler
C. Enables low grade fuel to be burnt
D. All of the above
Answer: D
325. O₂ content in atmospheric air on weight basis is
A. 21 %
B. 23 %
C. 30 %
D. 40 %
Answer: B
326. Rateau turbine is
A. Simple reaction turbine
B. Velocity compounded turbine
C. Pressure compounded turbine
D. Pressure-velocity compounded turbine
Answer: C
327. The function of a valve rod is
A. To provide reciprocating motion to the slide valve
B. To convert reciprocating motion of the piston into rotary motion of the crank
C. To convert rotary motion of the crankshaft into to and fro motion of the valve rod
D. To provide simple harmonic motion to the D-slide valve
Answer: D
328. The condition of steam in boiler drum is always
A. Dry
B. Wet
C. Saturated
D. Supersaturated
Answer: B
329. The density of supersaturated steam is about __________ that of the ordinary saturated vapor at the corresponding pressure.
A. Same as
B. 2 times
C. 4 times
D. 8 times
Answer: D
330. The missing quantity per stroke is equal to
A. Cylinder feed indicated mass of steam
B. Cylinder feed + indicated mass of steam
C. Mass of cushion steam + indicated mass of steam
D. Mass of cushion steam + cylinder feed
Answer: A
331. The saturation temperature of steam with increase in pressure increases
A. Linearly
B. Rapidly first and then slowly
C. Slowly first and then rapidly
D. Inversely
Answer: B
332. Thermal equilibrium means that the flow of steam is
A. Isothermal
B. Isentropic
C. Hyperbolic
D. Polytropic
Answer: B
333. Willian’s line follows the law (where b = A constant representing the shape of the Willian’s line, a = Another constant i.e. no load consumption per hour, I.P. = Indicated power, and m = Steam consumption per hour)
A. I.P. = a × m + b
B. m = a + b × I.P.
C. I.P. = b × m + a
D. m = (b/I.P.) – a
Answer: B
334. Equivalent evaporation of water is the evaporation for a feed water supply at 100°C
A. And its corresponding conversion into dry saturated steam at 100°C and 1.033 kg/cm²
B. And its corresponding conversion into dry steam at desired boiler pressure
C. Conversion into steam at atmospheric condition
D. Conversion into steam at the same pressure at which feed water is supplied
Answer: A
335. The difference of supersaturated temperature and saturation temperature at that pressure is called
A. Degree of super-saturation
B. Degree of superheat
C. Degree of under-cooling
D. None of these
Answer: C
336. The diameter of internal flue tubes of a Lancashire boiler is about _________ that of its shell.
A. One-fourth
B. One-third
C. Two-fifth
D. One-half
Answer: C
337. The biggest size of thermal power unit operating in India is
A. 30 MW
B. 60 MW
C. 100 MW
D. 500 MW
Answer: D
338. The ratio of the isentropic heat drop to the heat supplied, is called
A. Reheat factor
B. Stage efficiency
C. Internal efficiency
D. Rankine efficiency
Answer: D
339. The ratio of the actual vacuum to the ideal vacuum in a condenser is called
A. Condenser efficiency
B. Vacuum efficiency
C. Nozzle efficiency
D. Boiler efficiency
Answer: B
340. Pick up the wrong statement about water tube boiler in comparison to fire tube boilers
A. Former occupies less space for same power
B. Rate of steam flow is more in former case
C. Former is used for high installed capacity
D. Chances of explosion are less in former case
Answer: D
341. The turbine blades are
A. Straight
B. Circular
C. Curved
D. None of these
Answer: C
342. The ratio of the temperature rise of cooling water to the vacuum temperature minus inlet cooling water temperature is called
A. Condenser efficiency
B. Vacuum efficiency
C. Nozzle efficiency
D. Boiler efficiency
Answer: A
343. The heat loss in a boiler takes place in the form of
A. Heat carried away by flue gases
B. Heat carried away by ash
C. Moisture present in fuel and steam formed by combustion of hydrogen in fuel
D. All of the above
Answer: D
344. Steam exhaust from high pressure turbine is reheated in
A. Boiler drums
B. Superheater tubes
C. Economizer
D. A separate coil located in convection path
Answer: D
345. The value of diagram factor depends upon
A. Initial conditions of steam
B. Back pressure
C. Initial pressure of steam
D. All of these
Answer: D
346. Green coal, in order to be burnt, must be
A. Heated sufficiently
B. Burnt in excess air
C. Heated to its ignition point
D. Burnt as powder
Answer: C
347. A safety valve usually employed with stationary boilers is
A. Lever safety valve
B. Dead weight safety valve
C. High steam and low water safety valve
D. All of these
Answer: D
348. The relative heat absorption for successively added equal areas of boiler convection heating surfaces
A. Increases
B. Decreases
C. Remain unaffected
D. First increases and then decreases
Answer: B
349. The pressure of steam in the engine cylinder at the beginning of the stroke is ________ the boiler pressure.
A. Equal to
B. Less than
C. Higher than
D. None of these
Answer: B
350. Adiabatic process is
A. Essentially an isentropic process
B. Non-heat transfer process
C. Reversible process
D. Constant temperature process
Answer: B
351. Lancashire boiler is
A. Stationary fire tube boiler
B. Internally fired boiler
C. Horizontal boiler
D. All of these
Answer: D
352. Cochran boiler is a
A. Horizontal fire tube boiler
B. Horizontal water tube boiler
C. Vertical water tube boiler
D. Vertical fire tube boiler
Answer: D
353. Blow off cock in a boiler is used to
A. Control the flow of steam from the boiler to the main pipe and to shut off the steam completely when required
B. Empty the boiler when required and to discharge the mud, scale or sediments which are accumulated at the bottom of the boiler
C. Put off fire in the furnace of the boiler when the level of water in the boiler falls to an unsafe limit
D. Increase the temperature of saturated steam without raising its pressure
Answer: B
354. The diameter of internal flue tubes in a Lancashire boiler compared to its shell is
A. One-half
B. One-third
C. Two-fourth
D. Two-fifth
Answer: D
355. When the circulation of water, in a boiler, is by convection currents which are set up during the heating of water, then the boiler is known as
A. Internally fired boiler
B. Externally fired boiler
C. Natural circulation boiler
D. Forced circulation boiler
Answer: C
356. Thermal efficiency of a thermal power plant is of the order of
A. 15 %
B. 20 %
C. 30 %
D. 45 %
Answer: C
357. The high steam and low water safety valve is not used in
A. Cochran boiler
B. Cornish boiler
C. Lancashire boiler
D. Locomotive boiler
Answer: D
358. Expanding steam to a very low pressure (high vacuum) in steam engines is
A. Desirable
B. Economical
C. Essential
D. Uneconomical
Answer: D
359. The cylinder dimensions of a compound engine may be designed on the basis of
A. Equal power developed in each cylinder for uniform turning moment
B. Equal initial piston loads on all pistons for obtaining same size of piston rod, connecting rod etc. for all cylinders
C. Equal temperature drop in each cylinder for economy of steam
D. All of the above
Answer: D
360. One kilowatt-hour energy is equivalent to
A. 1000 J
B. 360 kJ
C. 3600 kJ
D. 3600 kW/sec
Answer: C
361. Which of the following boiler is best suited to meet the fluctuating demand of steam?
A. Locomotive boiler
B. Lancashire boiler
C. Cornish boiler
D. Babcock and Wilcox boiler
Answer: A
362. In locomotive boiler, maximum steam pressure is limited to
A. 1 kg/cm²
B. 5 kg/cm²
C. 10 kg/cm²
D. 18 kg/cm²
Answer: D
363. The fire tubes in a Cochran boiler usually have _________ diameter.
A. 6.25 mm
B. 62.5 mm
C. 72.5 mm
D. 92.5 mm
Answer: B
364. Boiler stays are used to
A. Prevent flat surfaces under pressure from tearing apart
B. Take care of failure in shear
C. Take care of failure in compression
D. Provide support for boiler
Answer: A
365. Which of the following is required for a steam condensing plant?
A. Condenser
B. Condensate pump
C. Air extraction pump
D. All of these
Answer: D
366. Spontaneous combustion is a phenomenon in which
A. All the fuel burns instantaneously producing high energy release
B. Fuel burns with less air
C. Coal bursts into flame without any external ignition source but by itself due to gradual increase in temperature as a result of heat released by combination of oxygen with coal
D. Explosion in furnace
Answer: C
367. Fire tube boilers are limited to a maximum working pressure of
A. 0.17 MN/m²
B. 1.7 MN/m²
C. 17 MN/m²
D. 170 MN/m²
Answer: B
368. Tertiary air is the air used to
A. Provide air around burners for obtaining optimum combustion
B. Transport and dry the coal
C. Cool the scanners
D. Convert CO (formed in lower zone of furnace) into CO₂ at higher zone
Answer: D
369. Desecration of feed water is carried out because it reduces
A. Cavitation of boiler feed pumps
B. Corrosion caused by oxygen
C. Heat transfer coefficient
D. pH value of water
Answer: B
370. The function of a safety valve is
A. To blow off steam when the pressure of steam inside the boiler exceeds the working pressure
B. To indicate the water level inside the boiler to an observer
C. To measure pressure of steam inside the steam boiler
D. None of the above
Answer: A
371. In a Woolf type compound engine, the high pressure and low pressure cylinders
A. Have common piston rod
B. Are set at 90°
C. Have separate piston rod
D. Are set in V arrangement
Answer: C
372. Carbonization of coal is the process of
A. Pulverizing coal in inert atmosphere
B. Heating wood in a limited supply of air at temperatures below 300°C
C. Strongly heating coal continuously for about 48 hours in the absence of air in a closed vessel
D. Binding the pulverized coal into briquettes
Answer: C
373. Cut-off ratio is the ratio of
A. Swept volume to the volume at cut-off
B. Volume at cut-off to the clearance volume
C. Volume at cut-off to the swept volume
D. Clearance volume to the volume at cut-off
Answer: C
374. The pressure at which latent heat of vaporisation of water is zero, is
A. Below atmospheric pressure
B. 1 kg/cm²
C. 100 kg/cm²
D. 225.6 kg/cm²
Answer: D
375. A compound steam engine in which piston rods of high pressure and low pressure cylinders ‘ are attached to two different cranks set at 180° to each other, is called
A. Receiver type compound engine
B. Tandem type compound engine
C. Woolf type compound engine
D. BothA. andB.
Answer: C
376. Which of the following gases has the highest calorific value?
A. Producer gas
B. Coal gas
C. Water gas
D. Blast furnace gas
Answer: B
377. The maximum steam pressure in a Locomotive boiler is limited to
A. 0.18 MN/m²
B. 1.8 MN/m²
C. 18 MN/m²
D. 180 MN/m²
Answer: B
378. Fire tube boilers are those in which
A. Flue gases pass through tubes and water around it
B. Water passes through the tubes and flue gases around it
C. Forced circulation takes place
D. Tubes are laid vertically
Answer: A
379. The ratio of heat equivalent to brake power to the energy supplied in steam is known as
A. Mechanical efficiency
B. Overall efficiency
C. Indicated thermal efficiency
D. Brake thermal efficiency
Answer: D
380. The difference between Cornish boiler and Lancashire boiler is that
A. Former is fire tube type and latter is water tube type boiler
B. Former is water tube type and latter is fire tube type
C. Former contains one fire tube and latter contains two fire tubes
D. None of the above
Answer: C
381. The function of a piston in a steam engine is
A. To guide motion of the piston rod and to prevent it from bending
B. To transfer motion from the piston to the cross-head
C. To convert heat energy of the steam into mechanical work id) to exhaust steam from the cylinder at proper moment
D. None of these
Answer: C
382. The pressure of reheat steam after passing through reheater compared to inlet condition is
A. More
B. Less
C. Equal
D. May be more or less depending on capacity of reheater
Answer: B
383. Willian’s line for the steam engine is a straight line relationship between the steam consumption per hour and
A. Indicated power
B. Brake power
C. Efficiency
D. Pressure of steam
Answer: A
384. Secondary air is the air used to
A. Provide air around burners for obtaining optimum combustion
B. Transport and dry the coal
C. Convert CO (formed in lower zone of furnace) into CO₂ at higher zone
D. Air delivered by induced draft fan
Answer: A
385. The function of a flywheel is
A. To convert reciprocating motion of the piston into rotary motion
B. To convert rotary motion of the crankshaft into to and fro motion of the valve rod
C. To prevent fluctuation of speed
D. To keep the engine speed uniform at all load conditions
Answer: C
386. During storage, the heating value of coal
A. Increases
B. Decreases
C. Remain constant
D. May increase or decrease depending upon the method of storage
Answer: B
387. A closed vessel made of steel and used for the generation of steam is called a
A. Steam boiler
B. Steam turbine
C. Steam condenser
D. Steam injector
Answer: A
388. The shell of the Cochran boiler is made hemispherical
A. To give maximum space and strength
B. To withstand the pressure of steam inside the boiler
C. BothA. andB.
D. None of the above
Answer: C
389. Sublimation region is the region where
A. Solid and vapor phases are in equilibrium
B. Solid and liquid phases are in equilibrium
C. Liquid and vapor phases are in equilibrium
D. Solid, liquid and vapor phases are in equilibrium
Answer: A
390. The ratio of brake power to the indicated power is known as
A. Mechanical efficiency
B. Overall efficiency
C. Indicated thermal efficiency
D. Brake thermal efficiency
Answer: A
391. While steam expands in turbines, theoretically the entropy
A. Remains constant
B. Increases
C. Decreases
D. Behaves unpredictably
Answer: A
392. A device used to put off fire in the furnace of the boiler when the level of water in the boiler falls to an unsafe limit, is called
A. Blow off cock
B. Stop valve
C. Superheater
D. None of these
Answer: D
393. Water tube boilers are those in which
A. Flue gases pass through tubes and water around it
B. Water passes through the tubes and flue gases around it
C. Work is done during adiabatic expansion
D. Change in enthalpy
Answer: C
394. When the circulation of water, in a boiler, is by a centrifugal pump, then the boiler is known as
A. Internally fired boiler
B. Externally fired boiler
C. Natural circulation boiler
D. Forced circulation boiler
Answer: D
395. Duplex feed pumps are used in small steam boilers. These operate on the principle of
A. Centrifugal pump
B. Axial flow pump
C. Gear pump
D. Reciprocating pump
Answer: D
396. An economiser is installed in a boiler primarily to
A. Superheat the steam
B. Reduce fuel consumption
C. Increase steam pressure
D. All of these
Answer: B
397. Which type of boiler can meet rapid changes of load?
A. Vertical fire tube type
B. Horizontal fire tube type
C. Horizontal water tube type
D. Forced circulation type
Answer: D
398. Besides mean effective pressure, the data required to determine the indicated power of an engine include
A. Piston diameter, length of stroke and calorific value of fuel
B. Piston diameter, specific fuel consumption and Calorific value of fuel
C. Piston diameter, length of stroke and speed of rotation
D. Specific fuel consumption, speed of rotation and torque
Answer: C
399. The basic purpose of drum in boiler is to
A. Serve as storage of steam
B. Serve as storage of feed water for water wall
C. Remove salts from water
D. Separate steam from water
Answer: D
400. The high pressure and low pressure cylinders in a receiver type compound engine are regarded as having cranks
A. 180° to each other
B. 90° to each other
C. 0° to each other
D. None of these
Answer: B
401. Steam in water tube boiler as compared to fire tube boiler
A. Can be raised rapidly
B. Is raised at slower rate
C. Is raised at same rate
D. Could be raised at fast/slow rate depending on design
Answer: A
402. When the speed of the engine is controlled by means of a valve in a steam pipe, which regulates the pressure of steam entering the engine, then the governing is known as
A. Throttle governing
B. Cut-off governing
C. By-pass governing
D. None of these
Answer: A
403. Proximate analysis of fuel is determination of percentage of
A. Carbon, hydrogen, nitrogen, sulphur, moisture
B. Fixed carbon, ash, volatile matter, moisture
C. Higher calorific value
D. Lower calorific value
Answer: B
404. A valve installed between the boiler and the feed pump is
A. Blow off cock
B. Feed check valve
C. Steam stop valve
D. None of these
Answer: B
405. Evaporative capacity of boiler is expressed as
A. kg of steam produced
B. Steam pressure produced
C. kg of fuel fired
D. kg of steam produced per kg of fuel fifed
Answer: D
406. A device in which some portion of waste heat of flue gases is recovered to heat the air before it passes to the furnace for combustion purpose, is known as
A. Superheater
B. Air-preheater
C. Economizer
D. Injector
Answer: B
407. The specific volume of steam with increase in pressure decreases
A. Linearly
B. Slowly first and then rapidly
C. Rapidly first and then slowly
D. Inversely
Answer: C
408. When the total heat of steam is h kJ/kg and the sensible heat of feed water is hf1 kJ/kg, then the factor of evaporation is given by
A. (h – hf1)/2257
B. (h + hf1)/2257
C. (h × hf1)/2257
D. None of these
Answer: A
409. The evaporation of 15.653 kg of water per hour from and at 100°C is called
A. Evaporative capacity
B. Factor of evaporation
C. Equivalent evaporation
D. One boiler h.p.
Answer: D
410. Which of the following are boiler accessories?
A. Economizer
B. Superheater
C. BothA. andB.
D. None of these
Answer: C
411. Lancashire boiler is of
A. Stationary < fire tube type
B. Horizontal type
C. Natural circulation type
D. All of the above
Answer: D
412. The actual power generated in the engine cylinder is called
A. Indicated power
B. Brake power
C. Frictional power
D. None of these
Answer: A
413. In regenerative air preheaters, the heat is transferred
A. From a metal wall from one medium to another
B. From heating an intermediate material and then heating the air from this material
C. By direct mixing
D. Heat is transferred by bleeding some gas from furnace
Answer: B
414. In case of non-condensing steam engines, the pressure of steam in the cylinder during exhaust stroke is _________ the condenser pressure.
A. Equal to
B. Lower than
C. Higher than
D. None of these
Answer: C
415. Alkaline pyrogallate is used in Orsat’s apparatus for absorption of
A. CO₂
B. CO
C. O₂
D. N₂
Answer: C
416. The draught produced by a steam jet issuing from a nozzle placed in the ash-pit under the fire grate of the furnace is called
A. Induced steam jet draught
B. Chimney draught
C. Forced steam jet draught
D. None of these
Answer: C
417. Equivalent evaporation is the amount of water evaporated in a boiler from and at
A. 0°C
B. 100°C
C. Saturation temperature at given pressure
D. Room temperature
Answer: B
418. The diameter of Cornish boiler varies from
A. 0.5 to 1 m
B. 1 to 2 m
C. 1.25 to 2.5 m
D. 2 to 3 m
Answer: B
419. In a throttling process
A. Heat transfer takes place
B. Work is done by the expanding steam
C. Internal energy of steam changes
D. None of the above
Answer: D
420. A device used in a boiler to control the flow of steam from the boiler to the main pipe and to shut off the steam completely when required, is known as
A. Blow off cock
B. Fusible plug
C. Superheater
D. Stop valve
Answer: D
421. A device in which some portion of waste heat of flue gases is recovered to heat the air before it passes to the furnace for combustion purpose, is known as
A. Superheater
B. Air-preheater
C. Economizer
D. Injector
Answer: B
422. The specific volume of steam with increase in pressure decreases
A. Linearly
B. Slowly first and then rapidly
C. Rapidly first and then slowly
D. Inversely
Answer: C
423. When the total heat of steam is h kJ/kg and the sensible heat of feed water is hf1 kJ/kg, then the factor of evaporation is given by
A. (h – hf1)/2257
B. (h + hf1)/2257
C. (h × hf1)/2257
D. None of these
Answer: A
424. The evaporation of 15.653 kg of water per hour from and at 100°C is called
A. Evaporative capacity
B. Factor of evaporation
C. Equivalent evaporation
D. One boiler h.p.
Answer: D
425. Which of the following are boiler accessories?
A. Economizer
B. Superheater
C. BothA. andB.
D. None of these
Answer: C
426. Lancashire boiler is of
A. Stationary < fire tube type
B. Horizontal type
C. Natural circulation type
D. All of the above
Answer: D
427. The actual power generated in the engine cylinder is called
A. Indicated power
B. Brake power
C. Frictional power
D. None of these
Answer: A
428. In regenerative air preheaters, the heat is transferred
A. From a metal wall from one medium to another
B. From heating an intermediate material and then heating the air from this material
C. By direct mixing
D. Heat is transferred by bleeding some gas from furnace
Answer: B
429. In case of non-condensing steam engines, the pressure of steam in the cylinder during exhaust stroke is _________ the condenser pressure.
A. Equal to
B. Lower than
C. Higher than
D. None of these
Answer: C
430. Alkaline pyrogallate is used in Orsat’s apparatus for absorption of
A. CO₂
B. CO
C. O₂
D. N₂
Answer: C
431. The draught produced by a steam jet issuing from a nozzle placed in the ash-pit under the fire grate of the furnace is called
A. Induced steam jet draught
B. Chimney draught
C. Forced steam jet draught
D. None of these
Answer: C
432. Equivalent evaporation is the amount of water evaporated in a boiler from and at
A. 0°C
B. 100°C
C. Saturation temperature at given pressure
D. Room temperature
Answer: B
433. The diameter of Cornish boiler varies from
A. 0.5 to 1 m
B. 1 to 2 m
C. 1.25 to 2.5 m
D. 2 to 3 m
Answer: B
434. In a throttling process
A. Heat transfer takes place
B. Work is done by the expanding steam
C. Internal energy of steam changes
D. None of the above
Answer: D
435. A device used in a boiler to control the flow of steam from the boiler to the main pipe and to shut off the steam completely when required, is known as
A. Blow off cock
B. Fusible plug
C. Superheater
D. Stop valve
Answer: D
436. The length of Cornish boiler is of the order of
A. 24 m
B. 35 m
C. 57.5 m
D. 79 m
Answer: C
437. The forced circulation of water does not take place in
A. LaMont boiler
B. Lancashire boiler
C. Velox boiler
D. Benson boiler
Answer: B
438. A fusible plug is fitted in small boilers in order to
A. Avoid excessive build up of pressure
B. Avoid explosion
C. Extinguish fire if water level in the boiler falls below alarming limit
D. Control steam dome
Answer: C
439. Which of the following statement is wrong?
A. The factor of evaporation for all boilers is always greater than unity
B. The amount of water evaporated in kg per kg of fuel burnt is called equivalent evaporation from and at 100° C
C. The ratio of heat actually used in producing the steam to the heat liberated in the furnace is called boiler efficiency
D. None of the above
Answer: D
440. Sulphur in coal results in
A. Corroding air heaters
B. Spontaneous combustion during coal storage
C. Facilitating ash precipitation
D. All of the above
Answer: D
441. Lancashire boiler has __________ internal flue tubes.
A. One
B. Two
C. Three
D. Four
Answer: B
442. For the same diameter and thickness of tube, a water tube boiler compared to a fire tube boiler has
A. More heating surface
B. Less heating surface
C. Equal heating surface
D. Heating surface depends on other parameters
Answer: A
443. The amount of water evaporated in kg per kg of fuel burnt is called
A. Evaporative capacity of a boiler
B. Equivalent evaporation from and at 100° C
C. Boiler efficiency
D. None of these
Answer: A
444. Heating of dry steam above saturation temperature is known as
A. Enthalpy
B. Superheating
C. Super saturation
D. Latent heat
Answer: B
445. The function of a piston rod is
A. To guide motion of the piston rod and to prevent it from bending
B. To transfer motion from the piston to the cross head
C. To convert heat energy of the steam into mechanical work
D. To exhaust steam from the cylinder at proper moment
Answer: B
446. At which pressure the properties of water and steam become identical
A. 0.1 kg/cm²
B. 1 kg/cm²
C. 100 kg/cm²
D. 225.6 kg/cm²
Answer: D
447. The actual power supplied by the engine crankshaft is called
A. Indicated power
B. Brake power
C. Frictional power
D. None of these
Answer: B
448. The diameter of cylindrical shell of the Lancashire boiler is of the order of
A. 1 to 1.25 m
B. 1 to 1.75 m
C. 2 to 4 m
D. 1.75 to 2.75 m
Answer: D
449. The length of Lancashire boiler varies from
A. 5 to 6 m
B. 6 to 7 m
C. 7.25 to 9 m
D. 9 to 10 m
Answer: C
450. The radius of a dished head is taken approximately as
A. One fourth
B. Half
C. One
D. Two
Answer: C
451. Fire tube boilers are
A. Internally fired
B. Externally fired
C. Internally as well as externally fired
D. None of these
Answer: A
452. Bomb calorimeter is used to determine
A. Higher calorific value at constant volume
B. Lower calorific value at constant volume
C. Higher calorific value at constant pressure
D. Lower calorific value at constant pressure
Answer: A
453. The clearance in the engine cylinder
A. Increases the mean effective pressure
B. Increases the workdone
C. Decreases the efficiency of the engine
D. All of these
Answer: D
454. Over fire burning is the phenomenon of
A. Supply of excess, air
B. Supply of excess coal
C. Burning CO and unburnt in upper zone of furnace by supplying more air
D. Fuel bed firing
Answer: C
455. The length of Cornish boiler varies from
A. 2 to 4.5 m
B. 3 to 5 m
C. 5 to 7.5 m
D. 7 to 9 m
Answer: C
456. Hard coke is produced by carburization of coal at
A. Atmospheric temperature
B. 500-600°C
C. 700-850°C
D. 950-1100°C
Answer: D
457. The water tubes in a simple vertical boiler are
A. Horizontal
B. Vertical
C. Inclined
D. None of these
Answer: C
458. The dry saturated steam at very high pressure (150200 kg/cm²) when throttled to atmosphere will become
A. Wet
B. Superheated
C. Remain dry saturated
D. Dry
Answer: A
459. Which of the following statement is correct?
A. Lancashire boiler is a fire tube boiler
B. Fire tube boilers are internally fired
C. Babcock and Wilcox boiler is a water tube boiler
D. All of the above
Answer: D
460. The best suited coal for chain or traveling grate stoker boiler is
A. Coking coal
B. Non-coking or free burning coal
C. Pulverized coal
D. High sulphur coal
Answer: B
461. The mechanical draught _________ with the amount of smoke.
A. Increases
B. Decreases
C. Does not effect
D. None of these
Answer: B
462. O₂ content in atmospheric air on volume basis is
A. 21 %
B. 23 %
C. 30 %
D. 40 %
Answer: A
463. The natural draught is produced by
A. Steam jet
B. Centrifugal fan
C. Chimney
D. BothA. andB.
Answer: C
464. Boiler parameters are expressed by
A. Tonnes/hr. of steam
B. Pressure of steam in kg/cm²
C. Temperature of steam in °C
D. All of the above
Answer: D
465. In forced circulation steam boilers, the force is applied
A. To draw water
B. To circulate water
C. To drain off the water
D. All of these
Answer: B
466. The coal requirement per kW hour generation in the thermal power plant is of the order of
A. 0.1 to 0.2 kg
B. 0.2 to 0.4 kg
C. 0.6 to 0.8 kg
D. 1.0 to 1.5 kg
Answer: C
467. The diameter of flue tube in a Cornish boiler is _________ that of the shell.
A. One-fourth
B. One-third
C. Two-fifth
D. Three-fifth
Answer: D
468. During polytropic process
A. Heat transfer takes place across cylinder walls
B. Work is done
C. Steam may be wet, dry or superheated after expansion
D. All of the above
Answer: D
469. The ratio of the clearance volume to the swept volume is called
A. Cut-off ratio
B. Expansion ratio
C. Clearance ratio
D. None of these
Answer: C
470. The fusible plug in small boilers is located
A. In the drum
B. In the fire tubes
C. Above steam dome
D. Over the combustion chamber
Answer: D
471. The rate of steam produced in Benson boiler is
A. 100 tonnes/h
B. 135 tonnes/h
C. 175 tonnes/h
D. 250 tonnes/h
Answer: B
472. Incomplete combustion can be best judged by
A. Smoky chimney exit
B. Excess air in flue gases
C. Measuring carbon monoxide in flue gases
D. Measuring temperature of flue gases at exit of furnace
Answer: C
473. Which of the following boiler works on a forced circulation of water?
A. Lamont boiler
B. Benson boiler
C. Loeffler boiler
D. All of these
Answer: D
474. Hygrometry deals with the
A. Hygroscopic substances
B. Water vapor in air
C. Temperature of air
D. Pressure of air
Answer: B
475. The length of shell of a Locomotive boiler is
A. 1 m
B. 2 m
C. 3 m
D. 4 m
Answer: D
476. The number of drums in Benson steam generator is
A. One
B. Two
C. One steam drum and one water drum
D. No drum
Answer: D
477. The chimney draught varies with
A. Climatic conditions
B. Temperature of furnace gases
C. Height of chimney
D. All of these
Answer: D
478. Pick up wrong statement about desired properties of a good fuel
A. High calorific value
B. Produce minimum smoke and gases
C. Ease in storing
D. High ignition point
Answer: D
479. Benson boiler requires
A. No drum
B. One drum
C. Two drums
D. Three drums
Answer: A
480. Natural water circulation, by convection in water tube boilers, with increase in pressure of boiler
A. Increases
B. Decreases
C. Remain unaffected
D. First increases and then decreases
Answer: B
481. The shell diameter of a Locomotive boiler is
A. 1 m
B. 1.5 m
C. 2 m
D. 2.5 m
Answer: B
482. The equivalent evaporation of a boiler is a measure to compare
A. The given boiler with the model
B. The two different boilers of the same make
C. Two different makes of boilers operating under the same operating conditions
D. Any type of boilers operating under any conditions
Answer: D
483. Water at pressure of 4 kg/cm² and 160°C temperature when exposed to atmosphere will
A. Boil
B. Flash i.e. get converted into steam
C. Remain as it was
D. Cool down
Answer: B
484. Locomotive type’ boiler is
A. Horizontal multi-tubular water tube boiler
B. Water wall enclosed furnace type
C. Vertical tubular fire tube type
D. Horizontal multi-tubular fire tube type
Answer: D
485. The function of injector used in small steam plants is to
A. Create vacuum in furnace
B. Create vacuum at turbine exhaust
C. Pump feed water
D. Dose chemicals in feed water
Answer: C
486. The function of injector used in small capacity boilers is to
A. Create vacuum
B. Inject chemical solution in feed pump
C. Pump water, similar to boiler feed pump
D. Add make up water in the system
Answer: C
487. Caking coals are those which
A. Form lumps or masses of coke
B. Burn freely
C. Show little or no fusing action
D. Burn completely
Answer: A
488. The balanced draft furnace is one using
A. Induced draft fan and chimney
B. Induced draft fan and forced draft fan
C. Forced draft fan and chimney
D. Any one of the above
Answer: B
489. Reheating of steam under ideal conditions takes place at constant
A. Entropy
B. Enthalpy
C. Pressure
D. Temperature
Answer: D
490. If a steam sample is nearly in dry condition, then its dryness fraction can be most accurately determined by
A. Throttling calorimeter
B. Separating calorimeter
C. Combined separating and throttling calorimeter
D. Bucket calorimeter
Answer: A
491. The specific heat of superheated steam in kcal/kg is generally of the order of
A. 0.1
B. 0.3
C. 0.5
D. 0.8
Answer: C
492. On Mollier chart, flow through turbine is represented by
A. Horizontal straight line
B. Vertical straight line
C. Straight inclined line
D. Curved line
Answer: B
493. A wet vapor can be completely specified by
A. Pressure only
B. Temperature only
C. Dryness fraction only
D. Pressure and dryness fraction
Answer: D
494. Water boils when its vapor pressure
A. Equals that of the surroundings
B. Equals 760 mm of mercury
C. Equals to atmospheric pressure
D. Equals the pressure of water in the container
Answer: A
495. An ideal regenerative cycle is
A. Equal to Carnot cycle
B. Less than Carnot cycle
C. More than Carnot cycle
D. Could be anything
Answer: B
496. The diameter of fire tube of Cornish boiler compared to its shell is
A. One half
B. One third
C. One fourth
D. One fifth
Answer: A
497. The number of flue tubes in Lancashire boiler is
A. Zero
B. One
C. Two
D. Four
Answer: C
498. The fire tubes in, a Coarran and Scottish marine boiler are
A. Horizontal
B. Vertical
C. Inclined
D. Both horizontal and vertical
Answer: A
499. A boiler in India should conform to safety regulations of
A. DIN
B. BS
C. ASTM
D. IBR
Answer: D
500. Thermal efficiency of well maintained boiler will be of the order
A. 40 %
B. 50 %
C. 75 %
D. 90 %
Answer: D
501. Size of boiler tubes is specified by
A. Mean diameter and thickness
B. Inside diameter and thickness
C. Outside diameter and thickness
D. Outside diameter and inside diameter
Answer: C
502. The diameter of fire tubes in Cochran boiler is of the order of
A. 2 cm
B. 6 cm
C. 8 cm
D. 12 cm
Answer: B
503. Gusset stays in a boiler are provided to
A. Prevent the bulging of flat surfaces
B. Avoid explosion in furnace
C. Prevent leakage of hot flue gases
D. Support furnace freely from top
Answer: A
504. Pulverized fuel is used for
A. Better burning
B. More calorific value
C. Less radiation loss
D. Medium sized units
Answer: A
505. Calorific value of coal is of the order of
A. 200-400 kcal/ kg
B. 800-1200 kcal/ kg
C. 2000-4000 kcal/ kg
D. 5000-8000 kcal/ kg
Answer: C
Steam Boilers Engines Nozzles and Turbines objective questions with answers pdf download online exam test
