Steam Boilers, Engines, Nozzles & Turbines 1000+ MCQ with answer for IBPS SO

1. In a throttling process
A. Steam temperature remains constant
B. Steam pressure remains constant
C. Steam enthalpy remains constant
D. Steam entropy remains constant
Answer : C

2. Expansion ratio is the ratio of
A. Swept volume to the volume at cut-off
B. Clearance volume to the swept volume
C. Volume at cut-off to the swept volume
D. Swept volume to the clearance volume
Answer : A

3. 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

4. The indicated thermal efficiency is defined as the
A. Ratio of thermal efficiency to the Rankine efficiency
B. Ratio of brake power to the indicated power
C. Ratio of heat equivalent to indicated power to the energy supplied in steam
D. Product of thermal efficiency and Rankine efficiency
Answer : C

5. When the total heat of steam is h kJ/kg and the sensible heat of feed water is h_f1 kJ/kg, then the factor of evaporation is given by
A. (h - h_f1)/2257
B. (h + h_f1)/2257
C. (h × h_f1)/2257
D. None of these
Answer : A

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

7. 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

8. A wet vapour can be completely specified by
A. Pressure only
B. Temperature only
C. Dryness fraction only
D. Pressure and dryness fraction
Answer : D

9. The velocity of steam at throat of the nozzle is __________ the velocity of sound.
A. Equal to
B. Less than
C. More than
D. None of these
Answer : A

10. 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

11. The cylindrical shell of a Lancashire boiler has diameter from
A. 1 to 2 m
B. 1.25 to 2.25 m
C. 1.5 to 2.5 m
D. 1.75 to 2.75 m
Answer : D

12. At critical point, i.e. p = 225.65 kg/cm², the latent enthalpy of vaporisation is
A. Maximum
B. Minimum
C. Zero
D. Depends on temperature also
Answer : C

13. It is required to produce large amount of steam at low pressure. Which boiler should be used?
A. Pulverised fuel fired boiler
B. Cochran boiler
C. Lancashire boiler
D. Babcock and Wilcox boiler
Answer : C

14. There is always some steam left in the clearance space from the previous stroke. This steam left in the clearance space is called
A. Wet steam
B. Saturated steam
C. Superheated steam
D. Cushion steam
Answer : D

15. The factor of evaporation for all boilers is always
A. Equal to unity
B. Less than unity
C. Greater than unity
D. None of these
Answer : C

16. 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

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

18. Over fire burning is the phenomenon of
A. Supply of excess, air
B. Supply of excess coal
C. Burning CO and unburnts in upper zone of furnace by supplying more air
D. Fuel bed firing
Answer : C

19. In a 50% reaction turbine stage, tangential component of absolute velocity at rotor inlet is 537 m/s and the blade velocity is 454 m/s. The power output in kW of steam will be
A. 260 kW
B. 282 kW
C. 296 kW
D. 302 kW
Answer : B

20. Pick up the correct statement as regards Cornish boiler and Lancashire boiler
A. Cornish is fire tube and Lancashire is water tube
B. Cornish is water tube and Lancashire is fire tube
C. Cornish has two fire tubes and Lancashire has one
D. Lancashire has two fire tubes and Cornish has one
Answer : D

21. The effect of friction in the nozzle __________ dryness fraction of steam.
A. Has no effect on
B. Decreases
C. Increases
D. None of these
Answer : C

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

23. 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

24. The heat loss in a boiler takes place in the form of
A. Heat carried away by flue gases
B. Heat carried away by ash
C. Moisture present in fuel and steam formed by combustion of hydrogen in fuel
D. All of the above
Answer : D

25. Desecration of feed water is carried out because it reduces
A. Cavitation of boiler feed pumps
B. Corrosion caused by oxygen
C. Heat transfer coefficient
D. pH value of water
Answer : B

26. Thermal equilibrium means that the flow of steam is
A. Isothermal
B. Isentropic
C. Hyperbolic
D. Polytropic
Answer : B

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

28. For water, at pressures below atmospheric;
A. Melting point rises slightly and boiling point drops markedly
B. Melting point rises markedly and boiling point drops markedly
C. Melting point drops slightly and boiling point drops markedly
D. Melting point drops slightly and boiling point drops slightly
Answer : A

29. The efficiency of a boiler is defined as
A. Ratio of heat actually used in producing steam to the heat liberated in the furnace
B. Ratio of the mass of steam produced to the mass of total water supplied in a given time
C. Ratio of the heat liberated in the furnace to the heat actually used in producing steam
D. None of the above
Answer : A

30. In a reaction turbine, when steam flows through the moving blades,
A. Pressure increases while velocity decreases
B. Pressure decreases while velocity increases
C. Pressure and velocity both decreases
D. Pressure and velocity both increases
Answer : C

31. Steam turbines are used for
A. Large marine propulsion
B. Electric power generation
C. Direct drive of fans, compressors, pumps
D. All of these
Answer : D

32. 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

33. When the circulation of water, in a boiler, is by a centrifugal pump, then the boiler is known as
A. Internally fired boiler
B. Externally fired boiler
C. Natural circulation boiler
D. Forced circulation boiler
Answer : D

34. The fire tubes in a Cochran boiler usually have _________ diameter.
A. 6.25 mm
B. 62.5 mm
C. 72.5 mm
D. 92.5 mm
Answer : B

35. 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

36. The expansion of steam in a nozzle follows
A. Carnot cycle
B. Rankine cycle
C. Joule cycle
D. Stirling cycle
Answer : B

37. Steam turbines may be classified according to
A. Direction of steam flow
B. Number of stages
C. Mode of steam action
D. All of these
Answer : D

38. In a steam condenser, the partial pressure of steam and air are 0.06 bar and 0.007 bar respectively. The condenser pressure is
A. 0.007 bar
B. 0.053 bar
C. 0.06 bar
D. 0.067 bar
Answer : D

39. The fittings mounted on the boiler for its proper and safe functioning is a
A. Water level indicator
B. Pressure gauge
C. Safety valve
D. All of these
Answer : D

40. The function of a valve rod is
A. To provide reciprocating motion to the slide valve
B. To convert reciprocating motion of the piston into rotary motion of the crank
C. To convert rotary motion of the crankshaft into to and fro motion of the valve rod
D. To provide simple harmonic motion to the D-slide valve
Answer : D

41. In water wall furnace, the heat is transferred to the water walls by
A. Convection
B. Radiation
C. Conduction
D. Radiation and conduction
Answer : B

42. Which of the following statement is correct?
A. A horizontal steam engine requires less floor area than a vertical steam engine
B. The steam pressure in the cylinder is not allowed to fall below the atmospheric pressure
C. The compound steam engines are generally non-condensing steam engines
D. All of the above
Answer : B

43. At which pressure the properties of water and steam become identical
A. 0.1 kg/cm²
B. 1 kg/cm²
C. 100 kg/cm²
D. 225.6 kg/cm²
Answer : D

44. The pressure velocity compounded impulse turbine allows a bigger pressure drop and hence __________ numbers of stages are required.
A. More
B. Less
C. Equal
D. None of these
Answer : B

45. A device in which some portion of waste heat of flue gases is recovered to heat the air before it passes to the furnace for combustion purpose, is known as
A. Superheater
B. Air-preheater
C. Economiser
D. Injector
Answer : B

46. 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. Forced circulation takes place
D. Tubes are laid vertically
Answer : A

47. Lancashire boiler is used where working pressure and power required are
A. Low
B. Moderate
C. High
D. None of these
Answer : B

48. Hard coke is produced by carburisation of coal at
A. Atmospheric temperature
B. 500-600°C
C. 700-850°C
D. 950-1100°C
Answer : D

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

50. 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