1000+ Steam Boilers, Engines, Nozzles & Turbines MCQ for SBI PO [Solved]

1. 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

2. 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

3. Heating wet steam at constant temperature is heating it at constant
A. Volume
B. Pressure
C. Entropy
D. Enthalpy
Answer : B

4. 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

5. For a Parson's reaction turbine, if ?? and ?? are fixed blade angles at inlet and exit respectively and ?? and ?? are the moving blade angles at entrance and exit respectively, then
A. ?? = ?? and ?? = ??
B. ?? = ?? and ??= ??
C. ?? < ?? and ?? > ??
D. ?? = ?? and ?? = ??
Answer : B

6. 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

7. 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

8. 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

9. The efficiency of the plant __________ with the mechanical draught.
A. Increases
B. Decreases
C. Remains constant
D. None of these
Answer : A

10. 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

11. Hygrometry deals with the
A. Hygroscopic substances
B. Water vapour in air
C. Temperature of air
D. Pressure of air
Answer : B

12. 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

13. Rateau turbine is
A. Simple reaction turbine
B. Velocity compounded turbine
C. Pressure compounded turbine
D. Pressure-velocity compounded turbine
Answer : C

14. 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

15. 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

16. 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

17. 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

18. 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

19. 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

20. 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

21. 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

22. 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

23. 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

24. 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

25. 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

26. 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

27. 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

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

29. Locomotive boiler is of the following type
A. Multi tubular
B. Horizontal
C. Internally fired
D. All of the above
Answer : D

30. 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

31. 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

32. 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

33. The flow through a nozzle is regarded as
A. Constant volume flow
B. Constant pressure flow
C. Isothermal flow
D. Isentropic flow
Answer : D

34. 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

35. 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

36. Lancashire boiler has __________ internal flue tubes.
A. One
B. Two
C. Three
D. Four
Answer : B

37. 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

38. 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

39. 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

40. 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

41. 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

42. The pressure of steam __________ while flowing through a nozzle.
A. Increases
B. Decreases
C. Remains constant
D. None of these
Answer : B

43. The diameter of superheated tubes in a locomotive boiler is
A. 13 mm
B. 31 mm
C. 130 mm
D. 230 mm
Answer : C

44. 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

45. 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

46. 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

47. 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

48. 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

49. 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

50. 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, p?) will be
A. 3.3 bar
B. 5.46 bar
C. 8.2 bar
D. 9.9 bar
Answer : B