Steam Boilers, Engines, Nozzles & Turbines MCQ Solved Paper for NEET

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

2. By compounding the expansion of steam in two or more cylinders, the ratio of expansion
A. Does not change
B. Increases
C. Decreases
D. None of these
Answer : C

3. In designing air preheaters, the important design consideration is that
A. Approach temperature should be as low as possible
B. Handling and maintenance should be easier
C. Heat transfer area should be optimum
D. Stack gases should not be cooled to the dew point
Answer : D

4. When the inlet pressure of steam is equal to the exit pressure, then
A. There is a pressure drop in the nozzle
B. Fluid flows through the nozzle
C. Pressure drops and fluid flows through the nozzle
D. There is no pressure drop and fluid does not flow through the nozzle
Answer : D

5. The number of flue tubes in Lancashire boiler is
A. Zero
B. One
C. Two
D. Four
Answer : C

6. The velocity of whirl at outlet for an axial discharge turbine is
A. Minimum
B. Maximum
C. Zero
D. None of these
Answer : C

7. The isentropic enthalpy drop in moving blade is two-third of the isentropic enthalpy drop in fixed blades of a turbine. The degree of reaction will be
A. 0.4
B. 0.56
C. 0.67
D. 1.67
Answer : A

8. 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 : B

9. With increase in load, radiant superheater has
A. Drooping characteristic
B. Linear characteristic
C. Rising characteristic
D. Flat characteristic
Answer : A

10. In fire 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 : B

11. 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

12. In forced recirculation 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 : C

13. The function of a crosshead is to guide motion of the _________ and to prevent it from bending.
A. Piston rod
B. Connecting rod
C. Eccentric rod
D. Valve rod
Answer : A

14. 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

15. The saturation temperature of steam with increase in pressure increases
A. Linearly
B. Rapidly first and then slowly
C. Slowly first and then rapidly
D. Inversely
Answer : B

16. A packaged boiler is one in which various parts like firing equipment, fans, feed pumps and automatic controls are
A. Supplied by same manufacturer loose and assembled at site
B. Supplied mounted on a single base
C. Purchased from several parties and packed together at site
D. Packaged boiler does not exist
Answer : B

17. The efficiency of a pressure-velocity compounded impulse turbine is __________ as compared to pressure compounded impulse turbine.
A. Same
B. Less
C. More
D. None of these
Answer : B

18. 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

19. The ratio of heat actually used in producing the steam to the heat liberated in the furnace, is known as
A. Equivalent evaporation
B. Factor of evaporation
C. Boiler efficiency
D. Power of a boiler
Answer : C

20. A compound steam engine in which piston rods of high pressure and low pressure cylinders ' are attached to two different cranks set at 180° to each other, is called
A. Receiver type compound engine
B. Tandem type compound engine
C. Woolf type compound engine
D. Both (A) and (B)
Answer : C

21. 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 : D

22. The density of supersaturated steam is about __________ that of the ordinary saturated vapour at the corresponding pressure.
A. Same as
B. 2 times
C. 4 times
D. 8 times
Answer : D

23. 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. Water space also
B. Chimney
C. Steam space
D. Superheater
Answer : C

24. The increase in pressure
A. Lowers the boiling point of a liquid
B. Raises the boiling point of a liquid
C. Does not affects the boiling point of a liquid
D. Reduces its volume
Answer : B

25. 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

26. The natural draught is produced by
A. Steam jet
B. Centrifugal fan
C. Chimney
D. Both (A) and (B)
Answer : C

27. On Mollier chart, free expansion, or throttling process from high pressure to atmosphere is represented by
A. Horizontal straight line
B. Vertical straight line
C. Straight inclined line
D. Curved line
Answer : A

28. The maximum discharge through a chimney occurs when the height of chimney is
A. Infinitely long
B. Around 200 meters
C. Equal to the height of the hot gas column producing draught
D. Outside temperature is very low
Answer : C

29. 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 : B

30. The process of maintaining the speed of the turbine constant for various load conditions, is known as
A. Bleeding
B. Reheating
C. Governing
D. None of these
Answer : C

31. The draught in locomotive boilers is produced by a
A. Chimney
B. Centrifugal fan
C. Steam jet
D. None of these
Answer : C

32. In a velocity compounded impulse turbine, when steam flows through the second row of moving blades,
A. Velocity increases
B. Velocity decreases
C. Velocity remains constant
D. Pressure remains constant
Answer : B

33. Which of the following is a fire tube boiler?
A. Locomotive boiler
B. Babcock and Wilcox boiler
C. Stirling boiler
D. All of the above
Answer : A

34. A vessel into which the steam is exhausted and condensed after doing work in an engine cylinder or turbine is known as
A. Steam condenser
B. Steam boiler
C. Steam preheater
D. Economiser
Answer : A

35. 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

36. Locomotive type' boiler is
A. Horizontal multi-tubular water tube boiler
B. Water wall enclosed furnace type
C. Vertical tubular fire tube type
D. Horizontal multi-tubular fire tube type
Answer : D

37. 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

38. 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

39. Parson's turbine is a
A. Simple impulse turbine
B. Simple reaction turbine
C. Impulse-reaction turbine
D. None of these
Answer : B

40. The impulse reaction turbine has its driving force
A. As an impulsive force
B. As a reaction force
C. Partly as an impulsive force and partly as a reaction force
D. None of the above
Answer : C

41. A closed vessel made of steel and used for the generation of steam is called a
A. Steam boiler
B. Steam turbine
C. Steam condenser
D. Steam injector
Answer : A

42. 1 kg.m is equal to
A. 9.81 Joules
B. 102 Joules
C. 427 Joules
D. None of these
Answer : A

43. Which of the following statement is correct for steam turbines as compared to reciprocating steam engines?
A. A steam turbine develops higher speeds
B. The efficiency of steam turbine is higher
C. The steam consumption is less
D. All of these
Answer : D

44. 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

45. Blading efficiency is also known as
A. Stage efficiency
B. Diagram efficiency
C. Nozzle efficiency
D. None of these
Answer : B

46. Natural water circulation, by convection in water tube boilers, with increase in pressure of boiler
A. Increases
B. Decreases
C. Remain unaffected
D. First increases and then decreases
Answer : B

47. A safety valve in a locomotive starts leaking. The leaking medium will be
A. Water
B. Dry steam
C. Wet steam
D. Super heated steam
Answer : D

48. The fire tubes in a Cochran boiler are
A. Horizontal
B. Vertical
C. Inclined
D. None of these
Answer : A

49. Tertiary air is the air used to
A. Provide air around burners for obtaining optimum combustion
B. Transport and dry the coal
C. Cool the scanners
D. Convert CO (formed in lower zone of furnace) into CO? at higher zone.
Answer : D

50. Latent heat of dry steam at atmospheric pressure is equal to
A. 539 kcal/ kg
B. 539 BTU/ lb
C. 427 kcal/ kg
D. 100 kcal/ kg
Answer : A