BOILER OPERATION
BOILER OPERATION MCQs
1:-Reverse osmosis for water treatment involves
A:-Removal of alkali salts
B:-Removal of total salts
C:-Removal of only hardness causing salts
D:-Removal of non-hardness salts
Ans: B
2:-When 100 kg of fuel with 60% carbon is burnt with theoretical air, the mass of `CO_(2)` released is
A:-319 kg
B:-4400 kg
C:-220 kg
D:-4500 kg
Ans: C
3:-Reduction of steam pressure in a process heating application will
A:-Reduce the steam temperature
B:-Reduce the sensible heat
C:-Increase the enthalpy of evaporation
D:-All of the above
Ans: D
4:-When pure hydrogen is burned, with theoretical air, the volume percentage of nitrogen in flue gas on dry basis will be ?
A:-100%
B:-79%
C:-21%
D:-0%
Ans: A
5:-Which of the following is not true of steam ?
A:-Highest specific heat and latent heat
B:-Low heat transfer coefficient
C:-Easy to control and distribute
D:-Cheap and inert
Ans: B
6:-The draught produced by the chimney is due to the
A:-Density difference between the column of hot gases inside the chimney and the cold air outside
B:-Pressure difference between the column of hot gases inside the chimney and the cold air outside
C:-Velocity difference between the column of hot gases inside the chimney and the cold air outside
D:-All of the above
Ans: A
7:-The efficiency of the chimney is directly proportional to the
A:-Height of the chimney
B:-Bottom area of the chimney
C:-Top area of the chimney
D:-None of the above
Ans: A
8:-The theoretical available draught at about __________ percentage of total static draught calculated.
A:-20
B:-40
C:-60
D:-80
Ans: D
9:-The function of a chimney in forced draught is
A:-To produce draught
B:-To discharge gases high in to the atmosphere
C:-To make draught and discharge gases to atmosphere
D:-None of the above
Ans: B
10:-Induced draught is used when
A:-An economiser is used
B:-An air preheater is used
C:-An economiser and air preheater are used
D:-None of the above
Ans: C
11:-Which is not true in the case of a steam jet draught ?
A:-It occupies minimum space
B:-It can't be started until high pressure steam is available
C:-Many classes of low grade fuels can be used
D:-Maintenance cost is very high
Ans: D
12:-The efficiency of artificial draught is nearly
A:-7%
B:-15%
C:-25%
D:-30%
Ans: A
13:-The efficiency of the chimney draught is hardly
A:-7%
B:-5%
C:-3%
D:-1%
Ans: D
14:-The fuel burning capacity of the grate mechanical draught in comparison with natural draught is
A:-Less
B:-High
C:-Same
D:-No comparison
Ans: B
15:-Which of the following statement is true as for as natural draught is cencerned ?
A:-No smoke
B:-Height of the chimney is less
C:-The running and maintenance cost is practically nil
D:-Low grate fuel can be used
Ans: C
16:-Which of the following fuel has maximum calorific value ?
A:-Paraffin
B:-Petrol
C:-Hydrogen
D:-Fuel oil
Ans: C
17:-What is the use of Orsat Apparatus ?
A:-To do volumetric analysis of dry flue gas
B:-To measure the calorific value of fuel
C:-To measure the water vapour contained in fuel
D:-To measure the size of the coal
Ans: A
18:-What is the higher calorific value of Natural Gas in (KJ/Cub.M) ?
A:-12200
B:-37800
C:-6080
D:-37000
Ans: D
19:-Water flow through pipe is measured by
A:-X-Rays
B:-Pitot Tube
C:-Electric Field
D:-Laser beams
Ans: B
20:-Reverse osmosis for water treatment involves
A:-Removal of total salts
B:-Removal of only hardness causing salts
C:-Removal of alkali salts
D:-Removal of non-hardness salts
Ans: A
21:-Good opportunity for energy savings from continuous blow down of boiler is by
A:-Recovery of flash steam for use in deaerator
B:-Using the blow down steam to run steam turbine
C:-Reusing the hot water so formed as make-up water
D:-None of the above
Ans: A
22:-Which fuel requires the lowest amount of excess air for combustion ?
A:-Pulverised coal
B:-Bagasse
C:-Fuel oil
D:-Natural gas
Ans: D
23:-Which data is not required to calculate the efficiency of boiler by indirect method ?
A:-Flue gas temperature
B:-Ambient temperature
C:-Calorific value of fuel
D:-Blow down rate
Ans: D
24:-The pour point of furnace oil (in deg. C) is
A:-100
B:-20
C:-50
D:-25
Ans: B
25:-In which of the following equipment is stored heat used for preheating combustion air ?
A:-Convective recuperator
B:-Radiation recuperator
C:-Regenerator
D:-Heat pump
Ans: C
26:-LPG is predominantly a mixture of propane and
A:-Butane
B:-Isopropane
C:-Methane
D:-Ethane
Ans: A
27:-The unit of specific heat is
A:-KCal/kg
B:-KCal/`m^(3)`
C:-KCal/kg°C
D:-KCal
Ans: C
28:-If the pressure of saturated steam is reduced through a pressure reducing valve
A:-Enthalpy of evaporation will reduce
B:-It will get superheated
C:-Enthalpy will reduce
D:-It will produce wet steam
Ans: B
29:-Radiation losses from a boiler practically
A:-Increase with increase in its % loading
B:-Decrease with increase in its % loading
C:-Are independent of its % loading
D:-None of the above
Ans: C
30:-Drain pockets are provided in a steam line for
A:-Effective removal of line condensate
B:-Effective removal of steam
C:-Removal of dirt
D:-Checking of steam line
Ans: A
A:-Removal of alkali salts
B:-Removal of total salts
C:-Removal of only hardness causing salts
D:-Removal of non-hardness salts
Ans: B
2:-When 100 kg of fuel with 60% carbon is burnt with theoretical air, the mass of `CO_(2)` released is
A:-319 kg
B:-4400 kg
C:-220 kg
D:-4500 kg
Ans: C
3:-Reduction of steam pressure in a process heating application will
A:-Reduce the steam temperature
B:-Reduce the sensible heat
C:-Increase the enthalpy of evaporation
D:-All of the above
Ans: D
4:-When pure hydrogen is burned, with theoretical air, the volume percentage of nitrogen in flue gas on dry basis will be ?
A:-100%
B:-79%
C:-21%
D:-0%
Ans: A
5:-Which of the following is not true of steam ?
A:-Highest specific heat and latent heat
B:-Low heat transfer coefficient
C:-Easy to control and distribute
D:-Cheap and inert
Ans: B
6:-The draught produced by the chimney is due to the
A:-Density difference between the column of hot gases inside the chimney and the cold air outside
B:-Pressure difference between the column of hot gases inside the chimney and the cold air outside
C:-Velocity difference between the column of hot gases inside the chimney and the cold air outside
D:-All of the above
Ans: A
7:-The efficiency of the chimney is directly proportional to the
A:-Height of the chimney
B:-Bottom area of the chimney
C:-Top area of the chimney
D:-None of the above
Ans: A
8:-The theoretical available draught at about __________ percentage of total static draught calculated.
A:-20
B:-40
C:-60
D:-80
Ans: D
9:-The function of a chimney in forced draught is
A:-To produce draught
B:-To discharge gases high in to the atmosphere
C:-To make draught and discharge gases to atmosphere
D:-None of the above
Ans: B
10:-Induced draught is used when
A:-An economiser is used
B:-An air preheater is used
C:-An economiser and air preheater are used
D:-None of the above
Ans: C
11:-Which is not true in the case of a steam jet draught ?
A:-It occupies minimum space
B:-It can't be started until high pressure steam is available
C:-Many classes of low grade fuels can be used
D:-Maintenance cost is very high
Ans: D
12:-The efficiency of artificial draught is nearly
A:-7%
B:-15%
C:-25%
D:-30%
Ans: A
13:-The efficiency of the chimney draught is hardly
A:-7%
B:-5%
C:-3%
D:-1%
Ans: D
14:-The fuel burning capacity of the grate mechanical draught in comparison with natural draught is
A:-Less
B:-High
C:-Same
D:-No comparison
Ans: B
15:-Which of the following statement is true as for as natural draught is cencerned ?
A:-No smoke
B:-Height of the chimney is less
C:-The running and maintenance cost is practically nil
D:-Low grate fuel can be used
Ans: C
16:-Which of the following fuel has maximum calorific value ?
A:-Paraffin
B:-Petrol
C:-Hydrogen
D:-Fuel oil
Ans: C
17:-What is the use of Orsat Apparatus ?
A:-To do volumetric analysis of dry flue gas
B:-To measure the calorific value of fuel
C:-To measure the water vapour contained in fuel
D:-To measure the size of the coal
Ans: A
18:-What is the higher calorific value of Natural Gas in (KJ/Cub.M) ?
A:-12200
B:-37800
C:-6080
D:-37000
Ans: D
19:-Water flow through pipe is measured by
A:-X-Rays
B:-Pitot Tube
C:-Electric Field
D:-Laser beams
Ans: B
20:-Reverse osmosis for water treatment involves
A:-Removal of total salts
B:-Removal of only hardness causing salts
C:-Removal of alkali salts
D:-Removal of non-hardness salts
Ans: A
21:-Good opportunity for energy savings from continuous blow down of boiler is by
A:-Recovery of flash steam for use in deaerator
B:-Using the blow down steam to run steam turbine
C:-Reusing the hot water so formed as make-up water
D:-None of the above
Ans: A
22:-Which fuel requires the lowest amount of excess air for combustion ?
A:-Pulverised coal
B:-Bagasse
C:-Fuel oil
D:-Natural gas
Ans: D
23:-Which data is not required to calculate the efficiency of boiler by indirect method ?
A:-Flue gas temperature
B:-Ambient temperature
C:-Calorific value of fuel
D:-Blow down rate
Ans: D
24:-The pour point of furnace oil (in deg. C) is
A:-100
B:-20
C:-50
D:-25
Ans: B
25:-In which of the following equipment is stored heat used for preheating combustion air ?
A:-Convective recuperator
B:-Radiation recuperator
C:-Regenerator
D:-Heat pump
Ans: C
26:-LPG is predominantly a mixture of propane and
A:-Butane
B:-Isopropane
C:-Methane
D:-Ethane
Ans: A
27:-The unit of specific heat is
A:-KCal/kg
B:-KCal/`m^(3)`
C:-KCal/kg°C
D:-KCal
Ans: C
28:-If the pressure of saturated steam is reduced through a pressure reducing valve
A:-Enthalpy of evaporation will reduce
B:-It will get superheated
C:-Enthalpy will reduce
D:-It will produce wet steam
Ans: B
29:-Radiation losses from a boiler practically
A:-Increase with increase in its % loading
B:-Decrease with increase in its % loading
C:-Are independent of its % loading
D:-None of the above
Ans: C
30:-Drain pockets are provided in a steam line for
A:-Effective removal of line condensate
B:-Effective removal of steam
C:-Removal of dirt
D:-Checking of steam line
Ans: A
31:-Flash steam can be recovered from
A:-Leaking steam
B:-Condensate at vacuum
C:-Condensate at high pressure
D:-Condensate at atmospheric pressure
Ans: C
32:-The correct value of 0° C on the Kelvin scale is
A:-273.15 K
B:-273 K
C:-273.85 k
D:-273.25 k
Ans: A
33:-Light year is a unit of
A:-Time
B:-Distance
C:-Mass
D:-Energy
Ans: B
34:-Temperature sensing can be achieved by the use of
A:-Thermocouples
B:-RTDs
C:-Thermistors
D:-All of the above
Ans: D
35:-What causes the piezoelectric effect ?
A:-Heat or dissimilar metals
B:-Water running on iron
C:-A magnetic field
D:-Pressure on a crystal
Ans: D
36:-Which among the following is not a fire tube boiler ?
A:-Cochran boiler
B:-Babcock and Wilcox boiler
C:-Lancashire boiler
D:-Locomotive boiler
Ans: B
37:-Which among the following is the characteristic of Cochran boiler ?
i. Vertical, multi-tube boiler.
ii. Used for small capacity steam generation.
iii. Water tube boiler.
A:-i, ii and iii are true
B:-i and iii are true
C:-i and ii are true
D:-Only iii is true
Ans: C
38:-What is the main requirement of locomotive boiler ?
A:-Easy maintenance
B:-Compact in size
C:-Any type of fuel can be used
D:-Produces steam at very high rate
Ans: D
39:-What is the operating pressure range of a Babcock and Wilcox boiler ?
A:-11.5 - 17.5 bar
B:-17.5 - 22.5 bar` `
C:-22.5 - 27.5 bar
D:-5.5 - 11.5 bar
Ans: A
40:-Which among the following biolers have minimum draught loss ?
A:-Lancashire boiler
B:-Scoth-marine boiler
C:-Babcock and Wilcox boiler
D:-Cochran boiler
Ans: C
41:-Which boiler is used in ships ?
A:-Cornish boiler
B:-Locomotive boilers
C:-Scotch-marine boiler
D:-Cochran boiler
Ans: C
42:-What is the rating of Fluidised Bed Boilers (FBB) ?
A:-200 bar and 400° C
B:-150 bar and 400° C
C:-200 bar and 450° C
D:-150 bar and 450° C
Ans: B
43:-Where among the following is Waste Heat Recovery boiler is used ?
i. Copper smelting industry.
ii. Steel mills.
iii. Pulp and paper.
iv. Refineries.
A:-i, ii and iii
B:-ii, iii and iv
C:-i, ii and iv
D:-i, ii, iii and iv
Ans: D
44:-The material used to control SOx in the FBC boiler is
A:-Lime
B:-Alumina
C:-Silica
D:-Limestone
Ans: D
45:-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:-Steam space
B:-Water space also
C:-Chimney
D:-Superheater
Ans: A
46:-Select a device which is not a boiler mountings ?
A:-Safety valve
B:-Water level indicator
C:-Economiser
D:-Pressure Gauge
Ans: C
47:-State the location of safety valve in a boiler
A:-Top of boiler shell
B:-Right side of boiler shell
C:-Bottom of boiler shell
D:-Left side of boiler shell
Ans: A
48:-Where is High-steam low water safety valve used ?
A:-Cochran boiler
B:-Lancashire boiler
C:-Babcock and Wilcox boiler
D:-Locomotive boiler
Ans: B
49:-Which among the following pressure measuring instrument is used as a pressure gauge in boiler ?
A:-Bellows
B:-Magnetic coupling
C:-Bourdon-tube
D:-Mc-Leod gauge
Ans: C
50:-What is the function of fusible plug ?
A:-Regulate pressure inside boiler
B:-Supply excess water needed
C:-Check water level
D:-Put-off fire in furnace, as water level fall
Ans: D
51:-What is the function of boiler accessories ?
A:-For operation and safety of boiler
B:-For cleaning and maintenance
C:-For increasing overall efficiency of boiler
D:-Anxiallary part to support boiler
Ans: C
52:-Which among the following boiler accessories preheats boiler feed water ?
A:-Air-preheaters
B:-Economiser
C:-Super-heaters
D:-Water-feeding equipment
Ans: B
53:-Where is air preheater placed ?
A:-After the economiser
B:-In the furnace
C:-Before the economiser
D:-In the chimney
Ans: A
54:-What is/are the advantage/s of super heater ?
i. It increases specific steam consumption of engines and turbines.
ii. It eliminates the erosion of the turbine blades.
iii. It reduces condensation losses in pipes and engine cylinder.
iv. Efficiency of steam plant is higher.
A:-i and iv
B:-ii and iv
C:-i, ii and iv
D:-i, ii, iii and iv
Ans: D
55:-What are the functions of blow-off cock ?
i. Empty boiler for cleaning and maintenance purpose.
ii. Supply water to the boiler high pressure continuously.
iii. Prevent the back-flow of water from boiler to pump.
iv. Discharge mud and sediments accumulated at the bottom of the boiler.
A:-i and iii
B:-ii and iii
C:-i and iv
D:-ii and iv
Ans: C
56:-Which of the following is the best way to assess boiler losses ?
A:-Benchmarking evaporation ratio
B:-Indirect efficiency evaluation
C:-Direct efficiency evaluation
D:-None of the above
Ans: B
57:-A boiler trial indicated 2% O2 at boiler exit and 7% O2 at stack. The in-leak air quantity between these two measurement is
A:-25%
B:-50%
C:-40%
D:-5%
Ans: C
58:-Enthalpy of evaporation of steam will be higher at
A:-2 kg/`cm^(2)`
B:-8 kg/`cm^(2)`
C:-12 kg/`cm^(2)`
D:-20 kg/`cm^(2)`
Ans: A
59:-The element that does not contribute to heating value during combustion process is
A:-Sulphur
B:-Hydrogen
C:-Carbon
D:-Nitrogen
Ans: D
60:-Which of the following is not one of the 3 T's of combustion ?
A:-Time
B:-Temperature
C:-Turbulence
D:-Tertiary
Ans: D
61:-Which of the following is not required in the boiler efficiency evaluation by direct method ?
A:-Steam flow
B:-Fuel flow
C:-Oxygen % in the flue gas
D:-Feed water temperature
Ans: C
62:-The dry saturated steam when throttled to a lower pressure will
A:-Become wet
B:-Become superheated
C:-Remain dry saturated
D:-Become condensate
Ans: B
63:-Velocity of steam in a pipe does strongly depend on
A:-Number of bends and valves in the pipe
B:-Specific volume of steam
C:-Length of the pipe
D:-None of the above
Ans: B
64:-Latent heat of steam at the critical point is
A:-Zero
B:-540 kCal/kg
C:-Infinite
D:-Equal to sensible heat
Ans: A
65:-Furnace oil contains 84% carbon by weight. How many kg of `CO_(2)` does complete combustion of 1 kg of furnace oil generate ?
A:-2.4
B:-4
C:-3.6
D:-3.1
Ans: D
66:-Which fuel releases the most energy per kg on complete combustion ?
A:-Carbon
B:-Sulphur
C:-Hydrogen
D:-Nitrogen
Ans: C
67:-How many kg of`` `CO_(2)` are produced in complete combustion of 16 kg of Methane ?
A:-42
B:-44
C:-16
D:-48
Ans: B
68:-In flue gas the theoretical `CO_(2)` is 15.5% and measured `CO_(2)` is 11% by volume. The percentage of excess air will be
A:-40.90%
B:-90.90%
C:-240.90%
D:-140.90%
Ans: A
69:-To drain condensate from main steam line, the following type of trap is a suitable trap
A:-Float
B:-Bimetallic
C:-Thermodynamic
D:-None of the above
Ans: B
70:-With increase in the percentage of excess air for combustion of coal, percentage of `CO_(2)` in flue gas.
A:-Decreases
B:-Increases
C:-Remains same
D:-None of the above
Ans: A
71:-The minimum capacity of any closed vessel which generates steam under pressure as per Indian Boilers Regulation Act is
A:-2.275 litres
B:-22.75 kilo litres
C:-227.5 litres
D:-22.75 litres
Ans: D
72:-If pressure of saturated steam increases then
A:-Enthalpy of steam goes up
B:-Enthalpy of steam goes down
C:-Enthalpy of evaporation goes up
D:-None of the above
Ans: A
73:-Water treatment for steam boilers is generally required to
A:-Remove hydrogen
B:-Prevent formation of scales
C:-Help improve combustion efficiency
D:-Reduce stack temperature
Ans: B
74:-The TDS level in boiler water for boiler blow down, is measured through
A:-Alkalinity of water
B:-Thermal conductivity of water
C:-Electrical conductivity of water
D:-Turbidity of water
Ans: C
75:-The heat which is required to change the phase from water at 100° C to saturated steam at 100° C at atm. pressure is
A:-Sensible heat
B:-Latent heat
C:-Super heat
D:-Specific heat
Ans: B
76:-The equipment having the highest efficiency in case of thermal power plant is
A:-Boiler
B:-Turbine
C:-Generator
D:-Cooling tower
Ans: C
77:-Excess air can be derived by mesuring the % of _____________ in flue gases.
A:-CO
B:-`O_(2)`
C:-`N_(2)`
D:-`SO_(2)`
Ans: B
78:-The heat loss dependant on chemical characteristics of liquid fuel is
A:-Unburnt loss
B:-Blowdown loss
C:-Radiation loss
D:-Hydrogen loss
Ans: D
79:-What type of steam is used for electric power generation in thermal power plants ?
A:-High pressure with superheat
B:-Dry saturate
C:-Wet steam
D:-None of the above
Ans: A
80:-High percentage of carbon monoxide presence in the flue gas of boiler is an indicator of
A:-High excess air
B:-Complete combustion
C:-Good control of the pollutants
D:-Low excess air
Ans: D
A:-Leaking steam
B:-Condensate at vacuum
C:-Condensate at high pressure
D:-Condensate at atmospheric pressure
Ans: C
32:-The correct value of 0° C on the Kelvin scale is
A:-273.15 K
B:-273 K
C:-273.85 k
D:-273.25 k
Ans: A
33:-Light year is a unit of
A:-Time
B:-Distance
C:-Mass
D:-Energy
Ans: B
34:-Temperature sensing can be achieved by the use of
A:-Thermocouples
B:-RTDs
C:-Thermistors
D:-All of the above
Ans: D
35:-What causes the piezoelectric effect ?
A:-Heat or dissimilar metals
B:-Water running on iron
C:-A magnetic field
D:-Pressure on a crystal
Ans: D
36:-Which among the following is not a fire tube boiler ?
A:-Cochran boiler
B:-Babcock and Wilcox boiler
C:-Lancashire boiler
D:-Locomotive boiler
Ans: B
37:-Which among the following is the characteristic of Cochran boiler ?
i. Vertical, multi-tube boiler.
ii. Used for small capacity steam generation.
iii. Water tube boiler.
A:-i, ii and iii are true
B:-i and iii are true
C:-i and ii are true
D:-Only iii is true
Ans: C
38:-What is the main requirement of locomotive boiler ?
A:-Easy maintenance
B:-Compact in size
C:-Any type of fuel can be used
D:-Produces steam at very high rate
Ans: D
39:-What is the operating pressure range of a Babcock and Wilcox boiler ?
A:-11.5 - 17.5 bar
B:-17.5 - 22.5 bar` `
C:-22.5 - 27.5 bar
D:-5.5 - 11.5 bar
Ans: A
40:-Which among the following biolers have minimum draught loss ?
A:-Lancashire boiler
B:-Scoth-marine boiler
C:-Babcock and Wilcox boiler
D:-Cochran boiler
Ans: C
41:-Which boiler is used in ships ?
A:-Cornish boiler
B:-Locomotive boilers
C:-Scotch-marine boiler
D:-Cochran boiler
Ans: C
42:-What is the rating of Fluidised Bed Boilers (FBB) ?
A:-200 bar and 400° C
B:-150 bar and 400° C
C:-200 bar and 450° C
D:-150 bar and 450° C
Ans: B
43:-Where among the following is Waste Heat Recovery boiler is used ?
i. Copper smelting industry.
ii. Steel mills.
iii. Pulp and paper.
iv. Refineries.
A:-i, ii and iii
B:-ii, iii and iv
C:-i, ii and iv
D:-i, ii, iii and iv
Ans: D
44:-The material used to control SOx in the FBC boiler is
A:-Lime
B:-Alumina
C:-Silica
D:-Limestone
Ans: D
45:-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:-Steam space
B:-Water space also
C:-Chimney
D:-Superheater
Ans: A
46:-Select a device which is not a boiler mountings ?
A:-Safety valve
B:-Water level indicator
C:-Economiser
D:-Pressure Gauge
Ans: C
47:-State the location of safety valve in a boiler
A:-Top of boiler shell
B:-Right side of boiler shell
C:-Bottom of boiler shell
D:-Left side of boiler shell
Ans: A
48:-Where is High-steam low water safety valve used ?
A:-Cochran boiler
B:-Lancashire boiler
C:-Babcock and Wilcox boiler
D:-Locomotive boiler
Ans: B
49:-Which among the following pressure measuring instrument is used as a pressure gauge in boiler ?
A:-Bellows
B:-Magnetic coupling
C:-Bourdon-tube
D:-Mc-Leod gauge
Ans: C
50:-What is the function of fusible plug ?
A:-Regulate pressure inside boiler
B:-Supply excess water needed
C:-Check water level
D:-Put-off fire in furnace, as water level fall
Ans: D
51:-What is the function of boiler accessories ?
A:-For operation and safety of boiler
B:-For cleaning and maintenance
C:-For increasing overall efficiency of boiler
D:-Anxiallary part to support boiler
Ans: C
52:-Which among the following boiler accessories preheats boiler feed water ?
A:-Air-preheaters
B:-Economiser
C:-Super-heaters
D:-Water-feeding equipment
Ans: B
53:-Where is air preheater placed ?
A:-After the economiser
B:-In the furnace
C:-Before the economiser
D:-In the chimney
Ans: A
54:-What is/are the advantage/s of super heater ?
i. It increases specific steam consumption of engines and turbines.
ii. It eliminates the erosion of the turbine blades.
iii. It reduces condensation losses in pipes and engine cylinder.
iv. Efficiency of steam plant is higher.
A:-i and iv
B:-ii and iv
C:-i, ii and iv
D:-i, ii, iii and iv
Ans: D
55:-What are the functions of blow-off cock ?
i. Empty boiler for cleaning and maintenance purpose.
ii. Supply water to the boiler high pressure continuously.
iii. Prevent the back-flow of water from boiler to pump.
iv. Discharge mud and sediments accumulated at the bottom of the boiler.
A:-i and iii
B:-ii and iii
C:-i and iv
D:-ii and iv
Ans: C
56:-Which of the following is the best way to assess boiler losses ?
A:-Benchmarking evaporation ratio
B:-Indirect efficiency evaluation
C:-Direct efficiency evaluation
D:-None of the above
Ans: B
57:-A boiler trial indicated 2% O2 at boiler exit and 7% O2 at stack. The in-leak air quantity between these two measurement is
A:-25%
B:-50%
C:-40%
D:-5%
Ans: C
58:-Enthalpy of evaporation of steam will be higher at
A:-2 kg/`cm^(2)`
B:-8 kg/`cm^(2)`
C:-12 kg/`cm^(2)`
D:-20 kg/`cm^(2)`
Ans: A
59:-The element that does not contribute to heating value during combustion process is
A:-Sulphur
B:-Hydrogen
C:-Carbon
D:-Nitrogen
Ans: D
60:-Which of the following is not one of the 3 T's of combustion ?
A:-Time
B:-Temperature
C:-Turbulence
D:-Tertiary
Ans: D
61:-Which of the following is not required in the boiler efficiency evaluation by direct method ?
A:-Steam flow
B:-Fuel flow
C:-Oxygen % in the flue gas
D:-Feed water temperature
Ans: C
62:-The dry saturated steam when throttled to a lower pressure will
A:-Become wet
B:-Become superheated
C:-Remain dry saturated
D:-Become condensate
Ans: B
63:-Velocity of steam in a pipe does strongly depend on
A:-Number of bends and valves in the pipe
B:-Specific volume of steam
C:-Length of the pipe
D:-None of the above
Ans: B
64:-Latent heat of steam at the critical point is
A:-Zero
B:-540 kCal/kg
C:-Infinite
D:-Equal to sensible heat
Ans: A
65:-Furnace oil contains 84% carbon by weight. How many kg of `CO_(2)` does complete combustion of 1 kg of furnace oil generate ?
A:-2.4
B:-4
C:-3.6
D:-3.1
Ans: D
66:-Which fuel releases the most energy per kg on complete combustion ?
A:-Carbon
B:-Sulphur
C:-Hydrogen
D:-Nitrogen
Ans: C
67:-How many kg of`` `CO_(2)` are produced in complete combustion of 16 kg of Methane ?
A:-42
B:-44
C:-16
D:-48
Ans: B
68:-In flue gas the theoretical `CO_(2)` is 15.5% and measured `CO_(2)` is 11% by volume. The percentage of excess air will be
A:-40.90%
B:-90.90%
C:-240.90%
D:-140.90%
Ans: A
69:-To drain condensate from main steam line, the following type of trap is a suitable trap
A:-Float
B:-Bimetallic
C:-Thermodynamic
D:-None of the above
Ans: B
70:-With increase in the percentage of excess air for combustion of coal, percentage of `CO_(2)` in flue gas.
A:-Decreases
B:-Increases
C:-Remains same
D:-None of the above
Ans: A
71:-The minimum capacity of any closed vessel which generates steam under pressure as per Indian Boilers Regulation Act is
A:-2.275 litres
B:-22.75 kilo litres
C:-227.5 litres
D:-22.75 litres
Ans: D
72:-If pressure of saturated steam increases then
A:-Enthalpy of steam goes up
B:-Enthalpy of steam goes down
C:-Enthalpy of evaporation goes up
D:-None of the above
Ans: A
73:-Water treatment for steam boilers is generally required to
A:-Remove hydrogen
B:-Prevent formation of scales
C:-Help improve combustion efficiency
D:-Reduce stack temperature
Ans: B
74:-The TDS level in boiler water for boiler blow down, is measured through
A:-Alkalinity of water
B:-Thermal conductivity of water
C:-Electrical conductivity of water
D:-Turbidity of water
Ans: C
75:-The heat which is required to change the phase from water at 100° C to saturated steam at 100° C at atm. pressure is
A:-Sensible heat
B:-Latent heat
C:-Super heat
D:-Specific heat
Ans: B
76:-The equipment having the highest efficiency in case of thermal power plant is
A:-Boiler
B:-Turbine
C:-Generator
D:-Cooling tower
Ans: C
77:-Excess air can be derived by mesuring the % of _____________ in flue gases.
A:-CO
B:-`O_(2)`
C:-`N_(2)`
D:-`SO_(2)`
Ans: B
78:-The heat loss dependant on chemical characteristics of liquid fuel is
A:-Unburnt loss
B:-Blowdown loss
C:-Radiation loss
D:-Hydrogen loss
Ans: D
79:-What type of steam is used for electric power generation in thermal power plants ?
A:-High pressure with superheat
B:-Dry saturate
C:-Wet steam
D:-None of the above
Ans: A
80:-High percentage of carbon monoxide presence in the flue gas of boiler is an indicator of
A:-High excess air
B:-Complete combustion
C:-Good control of the pollutants
D:-Low excess air
Ans: D
81. In reaction turbines
1) the steam is expanded in nozzles and there is no fall in pressure as the steam passes over the rotor blades
2) steam is directed over bucket-like-blades which propels the rotor
3) expansion of steam takes place as it passes through the moving blades on the rotor as well as through the guide blades fixed to the casing
4) steam pressure remains constant
Ans: 3
82. Lumped system analysis of transient heat conduction situation is valid when the biot number is
1) very small
2) very large
3) approximately one
4) cannot say unless the fourier number is known
Ans: 1
83. The number of degrees of freedom in a planar mechanism having n links and j simple hinge joints is :
1) 3 (n-3) - 2j
2) 3(n-1) - 2j
3) 3n - 2j
4) 2j - 3n +4
Ans: 2
84. Tolerances are specified
1) to obtain desired fits
2) because it's not possible to manufacture a size exactly
3) to obtain high accuracy
4) to have proper allowance
Ans: 2
85. Bleeding in turbine means
1) leakage of steam
2) steam doing no useful work
3) extracted steam for pre-heating feed water
4) removal of condensed steam
Ans: 3
86. In drop forging, forging is done by dropping
1) the work piece at high velocity
2) the hammer at high velocity
3) the die with hammer at high velocity
4) a weight on hammer to produce the requisite impact
Ans: 3
87. A cantilever beam having square cross section of side a is subjected to an end load. if a is increased by 19% the tip deflection decreases approximately
1) 19%
2) 29%
3) 41%
4) 50%
Ans: 4
1) the steam is expanded in nozzles and there is no fall in pressure as the steam passes over the rotor blades
2) steam is directed over bucket-like-blades which propels the rotor
3) expansion of steam takes place as it passes through the moving blades on the rotor as well as through the guide blades fixed to the casing
4) steam pressure remains constant
Ans: 3
82. Lumped system analysis of transient heat conduction situation is valid when the biot number is
1) very small
2) very large
3) approximately one
4) cannot say unless the fourier number is known
Ans: 1
83. The number of degrees of freedom in a planar mechanism having n links and j simple hinge joints is :
1) 3 (n-3) - 2j
2) 3(n-1) - 2j
3) 3n - 2j
4) 2j - 3n +4
Ans: 2
84. Tolerances are specified
1) to obtain desired fits
2) because it's not possible to manufacture a size exactly
3) to obtain high accuracy
4) to have proper allowance
Ans: 2
85. Bleeding in turbine means
1) leakage of steam
2) steam doing no useful work
3) extracted steam for pre-heating feed water
4) removal of condensed steam
Ans: 3
86. In drop forging, forging is done by dropping
1) the work piece at high velocity
2) the hammer at high velocity
3) the die with hammer at high velocity
4) a weight on hammer to produce the requisite impact
Ans: 3
87. A cantilever beam having square cross section of side a is subjected to an end load. if a is increased by 19% the tip deflection decreases approximately
1) 19%
2) 29%
3) 41%
4) 50%
Ans: 4
88. In a vapour compression refrigeration system, the working fluid is superheated vapour at entrance to
1) evaporator
2) condenser
3) compressor
4) expansion valve
Ans: 2
89. In an impulse turbine stage, pressure
1) increases in stator and decreases in rotor
2) decreases in stator and increases in rotor
3) decreases in stator and remains constant in rotor
4) remains constant in both stator and rotor
Ans: 3
90. During inelastic collision of two particles, which one of the following is conserved ?
1) total kinetic energy only
2) total linear momentum only
3) both linear momentum and kinetic energy
4) neither linear momentum nor kinetic energy
Ans: 2
91. Two identical ball bearing p and q are operating at loads 30 kn and 45 kn respectively. the ratio of the life of bearing p to the life of bearing q is
1) 81/16
2) 27/8
3) 9/4
4) 3/2
Ans: 2
92. For a laminar flow through a pipe, the discharge varies
1) as the square of the diameter
2) as the inverse of viscosity
3) inversely as the pressure gradient
4) as the square of viscosity
Ans: 2
93. The ratio of crippling load, for a column of length (l) with both ends fixed to the crippling load of the same column with both ends hinged is equal to
1) 2.0
2) 4.0
3) 0.25
4) 0.50
Ans: 2
94. A humidification process means
1) decrease in relative humidity
2) an increase in specific humidity
3) a decrease in temperature
4) an increase in temperature
Ans: 2
95. Coal fired power plant boilers manufactured in india generally use
1) pulverised fuel combustion
2) fluidised bed combustion
3) circulating fluidised bed combustion
4) moving stoker firing system
Ans: 1
96. In a refrigeration system, expansion valve is incorporated between
1) evaporator and compressor
2) condenser and evaporator
3) compressor and condenser
4) superheater and subcooler
Ans: 2
97. Which of the following is a solid state joining process ?
1) gas tungsten arc welding
2) resistance spot welding
3) friction welding
4) submerged arc welding
Ans: 3
98. The ratio of lateral strain to longitudinal strain is called
1) bulk modulus
2) modulus of rigidity
3) modulus of elasticity
4) poisson's ratio
Ans: 4
99. In a reaction stage turbine, the velocity
1) increases in stator and remains constant in rotor
2) increases in stator and decreases in rotor
3) decreases in stator and remains constant in rotor
4) remains constant throughout
Ans: 2
100. Consider the following statements : in a shell and tube heat exchanger, baffles are provided on the shell side to (a) prevent the stagnation of shell side fluid (b) improve heat transfer (c) provide support for tubes (d) prevent fouling of the above four statements the correct ones are
1) (b), (c) and (d)
2) (a), (b) and (c)
3) (a), (c) and (d)
4) (a), (b) and (d)
Ans: 2
1) evaporator
2) condenser
3) compressor
4) expansion valve
Ans: 2
89. In an impulse turbine stage, pressure
1) increases in stator and decreases in rotor
2) decreases in stator and increases in rotor
3) decreases in stator and remains constant in rotor
4) remains constant in both stator and rotor
Ans: 3
90. During inelastic collision of two particles, which one of the following is conserved ?
1) total kinetic energy only
2) total linear momentum only
3) both linear momentum and kinetic energy
4) neither linear momentum nor kinetic energy
Ans: 2
91. Two identical ball bearing p and q are operating at loads 30 kn and 45 kn respectively. the ratio of the life of bearing p to the life of bearing q is
1) 81/16
2) 27/8
3) 9/4
4) 3/2
Ans: 2
92. For a laminar flow through a pipe, the discharge varies
1) as the square of the diameter
2) as the inverse of viscosity
3) inversely as the pressure gradient
4) as the square of viscosity
Ans: 2
93. The ratio of crippling load, for a column of length (l) with both ends fixed to the crippling load of the same column with both ends hinged is equal to
1) 2.0
2) 4.0
3) 0.25
4) 0.50
Ans: 2
94. A humidification process means
1) decrease in relative humidity
2) an increase in specific humidity
3) a decrease in temperature
4) an increase in temperature
Ans: 2
95. Coal fired power plant boilers manufactured in india generally use
1) pulverised fuel combustion
2) fluidised bed combustion
3) circulating fluidised bed combustion
4) moving stoker firing system
Ans: 1
96. In a refrigeration system, expansion valve is incorporated between
1) evaporator and compressor
2) condenser and evaporator
3) compressor and condenser
4) superheater and subcooler
Ans: 2
97. Which of the following is a solid state joining process ?
1) gas tungsten arc welding
2) resistance spot welding
3) friction welding
4) submerged arc welding
Ans: 3
98. The ratio of lateral strain to longitudinal strain is called
1) bulk modulus
2) modulus of rigidity
3) modulus of elasticity
4) poisson's ratio
Ans: 4
99. In a reaction stage turbine, the velocity
1) increases in stator and remains constant in rotor
2) increases in stator and decreases in rotor
3) decreases in stator and remains constant in rotor
4) remains constant throughout
Ans: 2
100. Consider the following statements : in a shell and tube heat exchanger, baffles are provided on the shell side to (a) prevent the stagnation of shell side fluid (b) improve heat transfer (c) provide support for tubes (d) prevent fouling of the above four statements the correct ones are
1) (b), (c) and (d)
2) (a), (b) and (c)
3) (a), (c) and (d)
4) (a), (b) and (d)
Ans: 2
