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
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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
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Thermal efficiency of well maintained boiler will be of the order
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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
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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
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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
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The flow through a nozzle is regarded as
A. Constant volume flow
B. Constant pressure flow
C. Isothermal flow
D. Isentropic flow
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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
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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
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The maximum heat loss is a boiler occurs due to
A. Moisture in fuel
B. Dry flue gases
C. Steam formation
D. Unburnt carbon
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Maximum energy loss in a boiler occurs due to
A. Unburnt carbon in ash
B. Incomplete combustion
C. Ash content
D. Flue gases
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The impulse turbine rotor efficiency will have a maximum value of 0.5 cos2 α, 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
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Which of the following substance will have same percentage in both proximate and ultimate analysis?
A. Ash
B. Volatile matter
C. Moisture
D. Hydrogen
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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
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All steam engines work on
A. Zeroth law of thermodynamics
B. First law of thermodynamics
C. Second law of thermodynamics
D. None of these
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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
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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
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The fire tubes in a Scotch marine boiler are
A. Horizontal
B. Vertical
C. Inclined
D. None of these
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The fire tubes in, a Coarran and Scottish marine boiler are
A. Horizontal
B. Vertical
C. Inclined
D. Both horizontal and vertical
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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
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