Boiler Objective Type Questions and answers

 Boiler Objective Type Questions and answers

Steam boiler Multiple Choice Questions

1. The ratio of heat actually used in producing the steam to the heat liberated in the furnace is called ________

a) Steam efficiency

b) Boiler efficiency

c) Evaporation capacity of a boiler

d) None of the above

Answer: Boiler efficiency


2. 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: Locomotive boiler


3. Which of the following is a water tube boiler ________

a) Locomotive boiler

b) Cornish boiler

c) Cochran boiler

d) Babcock and Wilcox boiler

Answer: Babcock and Wilcox boiler


4. 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 is enthalpy

Answer: Water passes through the tubes and flue gases around it


5. 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: 157 fire tubes and 24 superheated tubes


6. Then biggest loss in the boiler is ________

a) Moisture in fuel

b) Dry in flue gases

c) Steam formation

d) Unburnt carbon

Answer: Dry flue gases


7. The draught in locomotive boilers is produced by a ________

a) Chimney

b) Centrifugal fan

c) Steam jet

d) All of the above

Answer: Steam jet


8. The draught may be produced by a ________

a) Chimney

b) Mechanical fan

c) Steam jet

d) All of the above

Answer: All of the above


9. The mechanical draught produces ________ draught than natural draught

a) More

b) Less

c) Equal

d) None of the above

Answer: More


10. Water tube boilers produces steam at a ________ pressure than that of fire tube boilers.

a) Higher

b) Lower

c) Same

d) None of the above

Answer: Higher


11. La-mont boiler,is a ________ pressure water tube steam boiler working on forced circulation

a) Low

b) High

c) Equal

d) All of the above

Answer: High


12. The efficiency of the plant ________ with the mechanical draught

a) Increases

b) Decreases

c) Remain constant

d) None of the above

Answer: Increases


13. The mechanical draught ________ the amount of smoke

a) Increases

b) Decreases

c) Does not effect

d) Remain same

Answer: Decreses


14. Thermal efficiency of well maintained boiler will be of the order ________

a) 30%

b) 55%

c) 90%

d) 45%

Answer: 90%


15. The chimney draught varies with ________

a) Climatic condition

b) Temperature of furnace gases

c) Height of chimney

d) All of the above

Answer: All of the above


16. The draught produced by a steam jet issuing from a nozzle placed in the chimney,is called ________

a) Induced steam jet draught

b) Forced steam jet draught

c) Chimney draught

d) None of the above

Answer: Induced steam jet draught


17. 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: Induced draught


18. Which of the following is best suited to meet fluctuating deamand of steam ________

a) Locomotive boiler

b) Lancashire boiler

c) Cornish boiler

d) Babcock boiler and wilcox boiler

Answer: Locomotive boiler


19. Cochran boiler is a ________

a) Horizontal fire tube boiler

b) Horizontal water tube boiler

c) Vertical water tube type

d) Vertical fire tube type

Answer: Vertical fire tube type


20. 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) Work is done during adiabatic expansion

d) Change is enthalpy

Answer: Flue gases pass through tubes and water around it


21. The diameter of fire tube of cornish boiler compared to its shell is ________

a) One-half

b) One-thired

c) Two-fifth

d) Three-fifth

Answer: Three-fifth


22. The length of cornish boiler is of the order of ________

a) 2-4 m

b) 3-5 m

c) 5-7.5 m

d) 7-9 m

Answer: 5-7.5 m


23. Cochran boiler is a ________

a) Horizontal fire tube boiler

b) Horizontal water tube boiler

c) Vertical water tube type

d) Vertical fire tube type

Answer: Vertical fire tube type


24. Which of the following is a fire tube boiler ________

a) Locomotive boiler

b) Cornish boiler

c) Cochran boiler

d) Babcock and Wilcox boiler

Answer: Locomotive boiler


25. The number of fire tubes in lancashire boiler is ________

a) Zero

b) One

c) Two

d) Four

Answer: Two


26. Lancashire boiler is of ________

a) Stationary fire tube-type

b) Horizontal type

c) Natural circulation type

d) All of the above

Answer: All of the above


27. Locomotive type boiler is a ________

a) Horizontal multitubular water tube boiler

b) Water wall enclosed furnace type

c) Vertical tubular fire tube type

d) Horizontal multitubular fire tube boiler

Answer: Horizontal multitubular fire tube boiler


28. Which of the folling is a water tube boiler ________

a) Locomotive boiler

b) Lancashire boiler

c) Cornish boiler

d) Babcock and wilcox boiler

Answer: Babcock and wilcox boiler


29. The economiser is used in boilers to ________

a) Increase thermal efficiency of boiler

b) Economise on fule

c) Extract heat from the exhaust the gases

d) Increase flue gas temperature

Answer: Increase thermal efficiency of boiler


30. An economiser in a boiler ________

a) Increases steam pressure

b) Increases steam flow

c) Decreases fuel consumption

d) Decreases steam pressure

Answer: Decreases fuel consumption


31. 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: Outside diameter and thickness


32. 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: 18 kg/cm2


33. The difference between cornish boiler and lancashire boiler is ________

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 boiler

c) Former contain one fire tube type and latter contains two water tube type boiler

d) None of the above

Answer: Former contain one fire tube type and latter contains two water tube type boiler


34. The water tubes in a babcock and wilcox boiler are ________

a) Horizontal

b) Vertical

c) Inclined

d) Horizontal and inclined

Answer: Inclined


35. Locomotive boiler is a following type ________

a) Multitubutar

b) Horizontal

c) Internally fired

d) All of the above

Answer: All of the above


36. 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: 1.5 m,4 m


37. The water tubes in a simple vertical boiler are

a) Horizontal

b) Vertical

c) Inclined

d) All of the above

Answer: Inclined


38. The diameter of fire tubes in cochran boiler is of the order of ________

a) 2 cm

b) 6 cm

c) 8 cm

d) 15 cm

Answer: 6 cm


39. Lancashire boiler is a ________

a) Stationary fire tube boiler

b) Internally fire tube boiler

c) Horizontal boiler

d) All of the above

Answer: All of the above


40. The diameter of internal flue tubes of a Lancashire boiler is about ________ that of it's shell

a) One-fourth

b) One-third

c) Two-fifth

d) One-half

Answer: Two-fifth


41. 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: Heated to its ignition point


42. 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: All of these


43. 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: Decreases


44. 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: Less than


45. Adiabatic process is

a) Essentially an isentropic process

b) Non-heat transfer process

c) Reversible process

d) Constant temperature process

Answer: Non-heat transfer process


46. Lancashire boiler is ________

a) Stationary fire tube boiler

b) Internally fired boiler

c) Horizontal boiler

d) All of these

Answer: All of these


47. 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: Vertical fire tube boiler


48. 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: Empty the boiler when required and to discharge the mud, scale or sediments which are accumulated at the bottom of the boiler


49. 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: Two-fifth


50. 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: Natural circulation boiler


51. Thermal efficiency of a thermal power plant is of the order of

a) 15 %

b) 20 %

c) 30 %

d) 45 %

Answer: 30 %


52. 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: Locomotive boiler


53. Expanding steam to a very low pressure (high vacuum) in steam engines is

a) Desirable

b) Economical

c) Essential

d) Uneconomical

Answer: Uneconomical


54. 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: All of the above


55. One kilowatt-hour energy is equivalent to

a) 1000 J

b) 360 kJ

c) 3600 kJ

d) 3600 kW/sec

Answer: 3600 kJ


Boiler Classification Multiple Choice Questions

1. Which type of boilers use orifice to control the flow circulation?

a) Natural circulation boilers

b) Forced convection boilers

c) Once-through boilers

d) Positive forced circulation boilers

Answer: Forced convection boilers


2. Which of these is a stationary boiler?

a) Locomotive boiler

b) Marine boiler

c) Mobile boiler

d) Babcock-Wilcox boiler

Answer: Babcock-Wilcox boiler


3. Stirling boiler is an example of which type of boiler?

a) Inclined tube boilers

b) Mobile boiler

c) Fire tube boiler

d) Water tube boiler

Answer: Water tube boiler


4. On what basis are fire and water tube boilers are classified?

a) Depending the combustion products formed

b) Depending the state of fuel

c) Depending on the steam formation rate

d) Depending tubular heating surface

Answer: Depending tubular heating surface


5. Which type of boiler is it when the furnace is placed in the region of boiling water?

a) Internally fired boiler

b) Externally fired boiler

c) Babcock-Wilcox boiler

d) Stirling boiler

Answer: Internally fired boiler


6. Cornish boiler is an example of which type of boiler?

a) Fire tube boiler

b) Water tube boiler

c) Vertical tube boiler

d) Externally fired boiler

Answer: Fire tube boiler


7. What is the steam pressure limit of natural circulation boilers?

a) 650bar

b) 180bar

c) 400bar

d) 550bar

Answer: 180bar


8. Which of these is a mobile boiler?

a) Lancashire boiler

b) Stirling boiler

c) Locomotive boiler

d) Cochran boiler

Answer: Locomotive boiler


9. Which type of boilers are called drum-less boilers?

a) Natural circulation boilers

b) Fire tube boilers

c) Positive forced circulation boiler

d) Forced circulation boiler

Answer: Positive forced circulation boiler


10. Which are the major types of boilers that are operated in world today?

a) Natural circulation boiler

b) Forced circulation boiler

c) Fire tube boiler

d) Once through boiler

Answer: Once through boiler


11. Out of the given option choose the advantage that supports fire tube boilers?

a) Water circulation is cyclic

b) Used as a mobile boiler

c) Water circulation is limited inside boiler shell

d) Bursting of flue tube does not cause any explosion

Answer: Water circulation is limited inside boiler shell


12. What is the advantage of having smaller ratio of water to steam space?

a) Steam can be generated at a faster even if the boiler is cold

b) Increases the rate of evaporation

c) Water is made cyclic, i.e., from boiler drum to water tube and back to drum

d) Helps in mobilizing the boiler

Answer: Steam can be generated at a faster even if the boiler is cold


13. Which of the given boilers operate above critical pressure?

a) Natural circulation boilers

b) Forced circulation boilers

c) Once-through boilers

d) Water tube boilers

Answer: Once-through boilers


14. Chances of sediments depositing inside the water tubes in the shell is less due to?

a) Low working pressure

b) Natural circulation of water

c) Partial circulation of water

d) High working pressure

Answer: High working pressure


15. Are boilers defined on the basis of heat source.

a) True

b) False

Answer: True


Function of Boilers Multiple Choice Questions

1. Which type of boilers is preferred cost wise when the boilers are required to raise less than 30 tonnes of steam?

a) Flued boiler

b) Cornish boiler

c) Butterley boiler

d) Shell boiler

Answer: Shell boiler


2. What increases as steam pressure increases inside a boiler?

a) Force

b) Density

c) Rate of steam conversion

d) Viscosity

Answer: Density


3. Why single boiler unit per turbine is equipped commonly?

a) For better turbine control

b) To deduce the costs

c) For overcoming losses of power

d) To improve the efficiency

Answer: For better turbine control


4. What is the function of boiler?

a) To burn the fuel in a confined closed system with the supply of air

b) To generate steam at varying pressure

c) To generate steam at constant pressure

d) To produce flue gases by burning fuel at a given pressure

Answer: To generate steam at constant pressure


5. What is the critical average pressure at which the single boiler unit per turbines is designed to handle?

a) 150 bar

b) 220 bar

c) 740 bar

d) 575 bar

Answer: 220 bar


6. In what is water in high pressure boiler circulated through?

a) Conduits

b) Cove

c) Channel

d) Tubes

Answer: Tubes


7. How can be the plant efficiency of steam power plant is increased?

a) By using high pressure and high temperature steam

b) By equipping ash and flue gas clearance system

c) By maintaining the boiler on daily basis by cleaning the soot and combustion products

d) By using better and efficient type of fuel for combustion

Answer: By maintaining the boiler on daily basis by cleaning the soot and combustion products


8. What is the temperature at which the steam boilers are capable to withstand?

a) 200°C

b) 280°C

c) 540°C

d) 358°C

Answer: 540°C


9. The _________ may have water circulation either by natural means due to difference in density or by external means.

a) Piping

b) Tubes

c) Furnace

d) Boiler

Answer: Boiler


10. What is needed to be increased to increase the heat transfer rate in the boiler?

a) Gas velocities

b) Fuel input

c) Water velocities

d) Air supply

Answer: Water velocities


Types of High Pressure Boilers Multiple Choice Questions

1. What type of boiler is a Benson boiler?

a) Super critical boiler

b) Fire tube boiler

c) Natural circulation boiler

d) Over-through boiler

Answer: Super critical boiler


2. In what form are the boiler’s tube arrange in Lamont boiler?

a) parallel in Vertical

b) Inclined vertically

c) parallel in horizontal

d) Horizontally inclined

Answer: parallel in horizontal


3. What is called as the heart of the Lamont boiler?

a) Water drum

b) Centrifugal pump

c) Furnace

d) Blower

Answer: Centrifugal pump


4. What type of boiler is a Lamont boiler?

a) Forced circulation

b) Natural circulation

c) Over-through

d) Positive forced circulation

Answer: Forced circulation


5. Through what is feed water from hot-well is passed through, before entering steam and water drum in Lamont boiler?

a) Evaporator tubes

b) Economizer

c) Distributer header

d) Circulating pump

Answer: Economizer


6. Through which does the even circulation of feed water is possible in Lamont boiler?

a) Nozzles

b) Water trough

c) Feed pump

d) Hose

Answer: Nozzles


7. In which year was Lamont boiler invented?

a) 1905

b) 1910

c) 1920

d) 1925

Answer: 1925


8. What is the pressure range between which Lamont boilers operates?

a) 80-120bar

b) 120-160bar

c) 180-360bar

d) 450-560bar

Answer: 120-160bar


9. Where is water steam separator drum located in Lamont boiler?

a) Inside of the boiler

b) Right above the furnace

c) Before the feed water pump

d) Outside of boiler

Answer: Outside of boiler


10. What type of steam is generated by evaporator tube of Lamont boiler?

a) Saturated steam

b) Unsaturated steam

c) Superheated steam

d) Flash steam

Answer: Saturated steam


11. What is the major disadvantage of the Benson boilers?

a) Boiler is big in size

b) Has large storage capacity

c) Deposition of salts

d) Bubble formation

Answer: Deposition of salts


12. What is the main disadvantage of Lamont boiler?

a) Less flexible in design

b) Low heat transfer rate

c) Formation of bubbles

d) Low steam generation capacity

Answer: Formation of bubbles


13. In which year was Benson boiler was invented?

a) 1918

b) 1920

c) 1921

d) 1922

Answer: 1922


14. What is the capacity of Benson boiler?

a) 180 tonnes/hr & above

b) 150 tonnes/hr & above

c) 250 tonnes/hr & above

d) 300 tonnes/hr & above

Answer: 150 tonnes/hr & above


15. Why starting valve is closed and valve 2 is opened while taking boiler on range in Benson boiler?

a) Avoid excessive heating of tube

b) To maintain the constant flow of water

c) To avoid pressure built up in tubes

d) To avoid pipe leakages at joints

Answer: Avoid excessive heating of tube


16. Which of the given boilers velocity of flue gases is greater than velocity of sound?

a) Benson boiler

b) La-Mont boiler

c) Schmidt-Hartmann boiler

d) Velox boiler

Answer: Velox boiler


17. Which boiler is most successful boiler in the gas turbine industries?

a) Because it has greater flexibility

b) It is easy to control, it’s fully automatic

c) It has higher thermal efficiency of all

d) Can increase heat transfer without changing its sizd

Answer: Can increase heat transfer without changing its size


18. What is done to increase the rate of heat transfer in the Velox boiler?

a) The boiler is heated upto very high range of temperature

b) The size of the boiler is changed as it is flexible

c) High grade fuel is made use for the combustion

d) Combustion gases are circulated through tubes with supersonic speed

Answer: Combustion gases are circulated through tubes with supersonic speed


19. f boiler is a Velox boiler?

a) Forced circulation boiler

b) Natural circulation boiler

c) Positively forced circulation boiler

d) Once- through boiler

Answer: Forced circulation boiler


20. What is used to heat the feed water which is used for recirculation through tubes?

a) Condenser

b) Pre-heater

c) Economizer

d) Water Clarifier

Answer: Economizer


21. How many circuits are there in the Schmidt-Hartmann boiler?

a) 3

b) 2

c) 4

d) 6

Answer: 2


22. Which type of circulation is incurred in Schmidt-Hartmann boiler?

a) Natural circulation

b) Positive forced circulation

c) Forced circulation

d) Once-through circulation

Answer: Natural circulation


23. Why pressure gauge and safety valve are made use of in the Schmidt-Hartmann boiler?

a) Safety against fire causes

b) To control the burst/blast of the boiler due to variance in pressure

c) Safe guard against leakage accidents

d) Act as controller against overheating of water in the boiler and boiler tubes

Answer: Safe guard against leakage accidents


24. Why are salts deposited on the evaporator drum?

a) Due to continuous circulation of water

b) Due to usage of hard water containing calcium content

c) Due to circulation of impure water

d) Due to the chemicals added in water

Answer: Due to circulation of impure water


25. What is feature of the Loffler boilers?

a) Evaporating water by super heated steam

b) Provide better efficiency by re-circulating gas coming out of turbine

c) Produce better steam quality by heating the boiler furnace above critical degrees

d) Eliminate the extra components used

Answer: Evaporating water by super heated steam


26. What is the major difficulty of the La-Mont boiler?

a) Unstable water circulation

b) Deposition of salts

c) Overheating of the components

d) Boiler working is slow

Answer: Deposition of salts


27. At what temperature is the water in convection super heater is heated of Loffler boiler?

a) 200°C

b) 300°C

c) 400°C

d) 500°C

Answer: 500°C


28. Which is the most recent economical method of power generation from boilers?

a) Natural circulation boiler

b) Fire tube boiler

c) Forced circulation

d) Super critical boiler

Answer: Super critical boiler


29. Which of the following boilers has the highest heat transfer capacity?

a) Subcritical boiler

b) Critical boiler

c) Forced circulation boiler

d) Supercritical boiler

Answer: Supercritical boiler


30. Overheating doesn’t occur in components of primary circuit Schmidt-Hartmann boiler.

a) True

b) False

Answer: False


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