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

1. The power of a boiler may be defined as
A. The ratio of heat actually used in producing the steam to the heat liberated in the furnace
B. The amount of water evaporated or steam produced in kg per kg of fuel burnt
C. The amount of water evaporated from and at 100° C into dry and saturated steam
D. The evaporation of 15.653 kg of water per hour from and at 100° C
Answer : B

2. The major axis of elliptical manholes on the shell should be provided
A. Longitudinally
B. Circumferentially
C. On dished end
D. Anywhere
Answer : B

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

4. 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

5. 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

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

7. 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 : D

8. Pick up wrong statement about desired properties of a good fuel
A. High calorific value
B. Produce minimum smoke and gases
C. Ease in storing
D. High ignition point
Answer : D

9. In forced circulation steam boilers, the force is applied
A. To draw water
B. To circulate water
C. To drain off the water
D. All of these
Answer : B

10. 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

11. Which of the following is steam dial?
A. Non-coking bituminous coal
B. Brown coal
C. Pulverised coal
D. Coking bituminous coal
Answer : A

12. 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 : D

13. De-Laval turbine is a
A. Simple impulse turbine
B. Simple reaction turbine
C. Impulse-reaction turbine
D. None of these
Answer : A

14. Which of the following is a water tube boiler?
A. Locomotive boiler
B. Cochran boiler
C. Cornish boiler
D. Babcock and Wilcox boiler
Answer : D

15. 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

16. Pick up the wrong statement about critical condition of steam
A. Latent heat is zero
B. Liquid directly becomes steam
C. Specific volume of steam and liquid is same
D. This is the maximum pressure limit
Answer : D

17. 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

18. In an impulse reaction turbine, the pressure drops gradually and continuously over
A. Fixed blades
B. Moving blades
C. Both fixed and moving blades
D. None of these
Answer : C

19. The diameter of cylindrical shell of the Lancashire boiler is of the order of
A. 1 to 1.25m
B. 1 to 1.75 m
C. 2 to 4 m
D. 1.75 to 2.75 m.
Answer : D

20. 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

21. 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

22. The flow of steam is supersonic
A. At the entrance to the nozzle
B. At the throat of the nozzle
C. In the convergent portion of the nozzle
D. In the divergent portion of the nozzle
Answer : D

23. An economiser _________ the steam raising capacity of a boiler.
A. Increases
B. Decreases
C. Has no effect on
D. None of these
Answer : A

24. The efficiency of an impulse turbine is maximum when (where V_b = Blade speed, V = Absolute velocity of steam entering the blade, and ? = Nozzle angle)
A. V_b = 0.5 V cos?
B. V_b = V cos?
C. V_b = 0.5 V² cos?
D. V_b = V² cos?
Answer : A

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

26. The diameter of fire tube of Cornish boiler compared to its shell is
A. One half
B. One third
C. One fourth
D. One fifth
Answer : A

27. The economiser is used in boilers to
A. Increase thermal efficiency of boiler
B. Economise on fuel
C. Extract heat from the exhaust flue gases
D. Increase flue gas temperature
Answer : A

28. 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

29. 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

30. The function of a piston rod is
A. To guide motion of the piston rod and to prevent it from bending
B. To transfer motion from the piston to the cross head
C. To convert heat energy of the steam into mechanical work
D. To exhaust steam from the cylinder at proper moment
Answer : B

31. 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

32. The function of a flywheel is
A. To convert reciprocating motion of the piston into rotary motion
B. To convert rotary motion of the crankshaft into to and fro motion of the valve rod
C. To prevent fluctuation of speed
D. To keep the engine speed uniform at all load conditions
Answer : C

33. 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

34. A double acting steam engine with a cylinder diameter of 190 mm and a stroke of 300 mm has a cut-off of 0.35. The expansion ratio for this engine is nearly
A. 1.05
B. 2.86
C. 6.65
D. 10.05
Answer : B

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

36. In an ideal impulse turbine, the
A. Absolute velocity at the inlet of moving blade is equal to that at the outlet
B. Relative velocity at the inlet of the moving blade is equal to that at the outlet
C. Axial velocity at inlet is equal to that at the outlet
D. Whirl velocity at inlet is equal to that at the outlet
Answer : B

37. In locomotives, the draught is produced by
A. Chimney
B. Induced draft fan
C. Both combined (A) and (B)
D. Steam jet draught
Answer : D

38. In a Woolf type compound engine, the high pressure and low pressure cylinders
A. Have common piston rod
B. Are set at 90°
C. Have separate piston rod
D. Are set in V-arrangement
Answer : C

39. The radius of a dished head is taken approximately as
A. One fourth
B. Half
C. One
D. Two
Answer : C

40. Feed water conditioning in thermal power plants in done to
A. Reduce hardness and for removal of solids
B. Increase efficiency of thermal power plant
C. Increase heat transfer rate
D. Increase steam parameters
Answer : A

41. 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

42. The ratio of heat equivalent to brake power to the energy supplied in steam is known as
A. Mechanical efficiency
B. Overall efficiency
C. Indicated thermal efficiency
D. Brake thermal efficiency
Answer : D

43. The change in internal energy in steam engines equals to
A. Work done during the Rankine cycle
B. Work done during compression
C. Work done during adiabatic expansion
D. Change in enthalpy
Answer : A

44. Which of the following statement is wrong?
A. The critical pressure gives the velocity of steam at the throat equal to the velocity of sound.
B. The flow in the convergent portion of the nozzle is subsonic.
C. The flow in the divergent portion of the nozzle is supersonic.
D. To increase the velocity of steam above sonic velocity (supersonic) by expanding steam below the critical pressure, the divergent portion for the nozzle is not necessary.
Answer : D

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. An air preheater is installed
A. Before the economiser
B. Before the superheater
C. Between the economiser and chimney
D. None of these
Answer : C

47. The heat balance sheet for the boiler shows the
A. Complete account of heat supplied by 1 kg of dry fuel and the heat consumed
B. Moisture present in the fuel
C. Steam formed by combustion of hydrogen per kg of fuel
D. All of the above
Answer : A

48. The critical pressure gives the velocity of steam at the throat
A. Equal to the velocity of sound
B. Less than the velocity of sound
C. More than the velocity of sound
D. None of these
Answer : A

49. 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

50. Benson boiler requires
A. No drum
B. One drum
C. Two drums
D. Three drums
Answer : A