1000+ Steam Boilers, Engines, Nozzles & Turbines Multiple Choice Question Answer [Solved]

1. 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

2. 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

3. 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

4. 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

5. 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

6. 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 CO? at higher zone
D. Air delivered by induced draft fan
Answer : A

7. Fire tube boilers are
A. Internally fired
B. Externally fired
C. Internally as well as externally fired
D. None of these
Answer : A

8. 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

9. The state of vapour under saturation condition is described by
A. Pressure alone
B. Temperature alone
C. Pressure and temperature
D. Pressure and dryness fraction
Answer : D

10. 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

11. 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

12. 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

13. 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

14. 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

15. 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

16. 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

17. 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

18. The discharge is __________ at critical pressure.
A. Zero
B. Minimum
C. Maximum
D. None of these
Answer : C

19. 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

20. 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

21. 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

22. The critical pressure ratio for initially dry saturated steam is
A. 0.546
B. 0.577
C. 0.582
D. 0.601
Answer : B

23. 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

24. 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

25. 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

26. The stage efficiency (?_S) is given by (where ?_B = Blading efficiency, and ?_N = Nozzle efficiency)
A. ?_S = ?_B × ?_N
B. ?_S = ?_B / ?_N
C. ?_S = ?_N / ?_B
D. None of these
Answer : A

27. 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

28. The forced circulation of water does not take place in
A. LaMont boiler
B. Lancashire boiler
C. Velox boiler
D. Benson boiler
Answer : B

29. 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

30. 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

31. 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 metres, 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

32. 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

33. 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

34. Reheating of steam under ideal conditions takes place at constant
A. Entropy
B. Enthalpy
C. Pressure
D. Temperature
Answer : D

35. The critical pressure ratio for gases is
A. 0.528
B. 0.546
C. 0.577
D. 0.582
Answer : A

36. 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

37. If partial pressure of air and steam be p_a and p_s respectively in a condenser, then according to Dalton's law, the pressure in condenser is equal to
A. p_s - p_a
B. p_a - p_s
C. p_a + p_s
D. None of these
Answer : C

38. Willians 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

39. Multi-stage steam turbines are of the
A. Velocity compounded type
B. Reaction type
C. Pressure compounded type
D. All of these
Answer : D

40. The mechanical draught _________ with the amount of smoke.
A. Increases
B. Decreases
C. Does not effect
D. None of these
Answer : B

41. 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