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

1. 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

2. If the critical pressure ratio for steam is 0.546, then the steam is initially
A. Wet steam
B. Dry saturated steam
C. Superheated steam
D. None of these
Answer : C

3. If a steam sample is nearly in dry condition, then its dryness fraction can be most accurately determined by
A. Throttling calorimeter
B. Separating calorimeter
C. Combined separating and throttling calorimeter
D. Bucket calorimeter
Answer : A

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

5. The latent heat of steam with increase of pressure
A. Remain same
B. Increases
C. Decreases
D. Behaves unpredictably
Answer : C

6. Which is not correct statement about the function of furnace?
A. To provide proper conditions for continuous complete combustion
B. Mix fuel with air and ignite
C. Separate ash from coal
D. Maintain heat supply to prepare and ignite the incoming fuel
Answer : C

7. Which of the following coals has the highest calorific value?
A. Anthracite coal
B. Bituminous coal
C. Lignite
D. Peat
Answer : A

8. The value of diagram factor depends upon
A. Initial conditions of steam
B. Back pressure
C. Initial pressure of steam
D. All of these
Answer : D

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

10. Hard coke is used in
A. Cement industry
B. Thermal power plant
C. Blast furnace
D. Domestic use
Answer : C

11. The reheat factor depends upon
A. Initial pressure and superheat
B. Exit pressure
C. Turbine stage efficiency
D. All of these
Answer : D

12. The function of injector used in small capacity boilers is to
A. Create vacuum
B. Inject chemical solution in feed pump
C. Pump water, similar to boiler feed pump
D. Add make up water in the system
Answer : C

13. 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

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

15. A condenser where circulating water flows through tubes which are surrounded by steam, in known as
A. Surface condenser
B. Jet condenser
C. Barometric condenser
D. Evaporative condenser
Answer : A

16. 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

17. 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

18. The ratio of total useful heat drop to the total isentropic heat drop, is called
A. Stage efficiency
B. Internal efficiency
C. Rankine efficiency
D. None of these
Answer : B

19. 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

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. The high pressure and low pressure cylinders in a Tandem type compound engine are regarded as having cranks
A. 180° to each other
B. 90° to each other
C. 0° to each other
D. None of these
Answer : C

22. Expanding steam to a very low pressure (high vacuum) in steam engines is
A. Desirable
B. Economical
C. Essential
D. Uneconomical
Answer : D

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

24. Superheating of steam is done at
A. Constant volume
B. Constant temperature
C. Constant pressure
D. Constant entropy
Answer : C

25. The basic job of feed water treatment in boilers is to overcome the problem of
A. Corrosion
B. Scale
C. Carryover
D. All of the above
Answer : D

26. Which of the following statement is wrong?
A. The mechanical draught reduces the height of chimney.
B. The natural draught reduces the fuel consumption.
C. A balanced draught is a combination of induced and forced draught.
D. All of the above
Answer : B

27. The water tubes in a Babcock and Wilcox boiler are
A. Horizontal
B. Vertical
C. Inclined
D. Horizontal and inclined
Answer : C

28. The aim of a compound steam engine is
A. To reduce the ratio of expansion in each cylinder
B. To reduce the length of stroke
C. To reduce the temperature range in each cylinder
D. All of the above
Answer : D

29. In natural 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 : A

30. 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

31. In cross compounding, the cylinders are arranged
A. Side by side and each cylinder has common piston, connecting rod and crank
B. Side by side and each cylinder has separate piston, connecting rod and crank
C. At 90° and each cylinder has common piston, connecting rod and crank
D. At 90° and each cylinder has separate piston, connecting rod and crank
Answer : B

32. For the same diameter and thickness of tube, a water tube boiler has ________ heating surface as compared to fire tube boiler.
A. More
B. Less
C. Equal
D. None of these
Answer : A

33. The evaporation of 15.653 kg of water per hour from and at 100°C is called
A. Evaporative capacity
B. Factor of evaporation
C. Equivalent evaporation
D. One boiler h.p.
Answer : D

34. 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

35. The average operating pressure of Benson boiler is
A. 100 bar
B. 150 bar
C. 200 bar
D. 250 bar
Answer : D

36. 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

37. The three Ts for good combustion are
A. Temperature, time, and turbulence
B. Total air, true fuel, and turbulence
C. Thorough mixing, total air and temperature
D. Total air, time, and temperature
Answer : A

38. The number of water level indicators in a boiler are generally _________ in number.
A. One
B. Two
C. Three
D. Four
Answer : B

39. 100% efficiency of a thermal cycle cannot be achieved because of
A. Frictional losses
B. It is not possible to achieve 0°K temperature
C. Leakage
D. Non availability of ideal substance
Answer : B

40. A turbine is said to have an axial discharge when the steam leaves the blade tip at _________ to the direction of the blade motion.
A. 60°
B. 90°
C. 180°
D. 270°
Answer : B

41. Carbonisation of coal is the process of
A. Pulverising coal in inert atmosphere
B. Heating wood in a limited supply of air at temperatures below 300°C
C. Strongly heating coal continuously for about 48 hours in the absence of air in a closed vessel
D. Binding the pulverised coal into briquettes
Answer : C

42. Which of the following statement is wrong?
A. Locomotive boiler is a water tube boiler
B. Water tube boilers are internally fired
C. Lamont boiler is a low pressure water tube boiler
D. All of the above
Answer : D

43. The working pressure range for a LaMont boiler is
A. 0.5 to 10 MN/m²
B. 1 to 15 MN/m²
C. 2.5 to 15 MN/m²
D. 3.5 to 20 MN/m²
Answer : D

44. Gradually increasing temperature of flue gases at inlet to chimney for given steam outputs is an indication of
A. Higher effectiveness of boiler
B. High calorific value coal being burnt
C. Fouling of heat transfer surfaces
D. Raising of steam temperature
Answer : C

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

46. 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

47. 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

48. The air pressure at the fuel bed is reduced below that of atmosphere by means of a fan placed at or near the bottom of the chimney to produce a draught. Such a draught is called
A. Natural draught
B. Induced draught
C. Forced draught
D. Balanced draught
Answer : B

49. Efficiency of Rankine cycle can be increased by
A. Decreasing initial steam pressure and temperature
B. Increasing exhaust pressure
C. Decreasing exhausts pressure
D. Increasing the expansion ratio
Answer : A

50. Heating of dry steam above saturation temperature is known as
A. Enthalpy
B. Superheating
C. Super saturation
D. Latent heat
Answer : B