Quiznetik

Thermal Engineering 2 | Set 2

1. In the expansion process, which of the following remains constant?

Correct : D. enthalpy

2. The COP of cycle is given by(Q2=heat absorbed by evaporator and Wc=work done by compressor)

Correct : C. q2/wc

3. Which of the following is recommended in a refrigeration cycle?

Correct : C. both of the mentioned

4. A condenser must and then the compressed refrigerant.

Correct : D. desuperheat, condense

5. In absorption refrigeration cycle, which of the following is used?

Correct : C. both of the mentioned

6. In absorption system, compressor in vapour compression cycle is replaced by absorber- generator assembly.

Correct : A. true

7. In the aqua-ammonia absorption system,

Correct : B. ammonia is the refrigerant and water is the absorbent

8. Which of the following statement is true?

Correct : A. ammonia vapour is absorbed in water

9. Which of the following condenses first?

Correct : B. water vapour

10. The vapour going to condenser is in temperature and in ammonia.

Correct : D. lower, richer

11. Lithium bromide-water vapour is another absorption refrigeration system.

Correct : A. true

12. Water is used as a in air conditioning units.

Correct : B. refrigerant

13. Room air conditioners and packaged units are examples of

Correct : A. direct expansion systems

14. Which of the following is not a component of packaged air conditioners?

Correct : C. chiller

15. In a chilled water system, the refrigerant is used to cool the air directly while in the direct expansion system, a secondary medium like water is used to cool the air.

Correct : B. false

16. In which component of the chilled water system, the return air and the fresh air mixture is filtered?

Correct : A. fan coil unit

17. Which of the following qualities is not possessed by the filters in the air conditioning system?

Correct : D. they should offer high frictional resistance to the airflow

18. Viscous type filters are made of screens of spilt wire and coated with non-drying viscous oil in order to catch and remove the dust particles from the incoming air.

Correct : A. true

19. Which of the following statements about electric precipitators is false?

Correct : D. dust particles get attached to the positive electrode

20. The process of extraction of the certain required amount of water from air is known as

Correct : D. dehumidification

21. Which of the following is capable of absorbing excess moisture from the air?

Correct : C. salts of calcium or ammonia

22. Open cooling system is also called as

Correct : B. once through system

23. How many number of spray nozzle does each module on spray pond cooling system contains?

Correct : D. 4

24. Which of the following is the simplest method of cooling the condenser water?

Correct : A. spray cooling pond

25. In which type of cooling system are nozzles arranged on different elevation?

Correct : B. double deck system

26. What are used in the direct flow system to transverse the pond before uniting at intake?

Correct : C. baffle walls

27. What type of cooling system is used in the large power plants?

Correct : C. cooling towers

28. How does outside air enter into the wet cooling system?

Correct : B. louvers

29. Why is exhaust steam coming out of turbine is admitted to a steam header?

Correct : C. to decrease the pressure drop

30. In which system is Cooling of hot water is done on tray as step by?

Correct : C. atmospheric cooling tower

31. How is air produced in mechanical draught cooling tower?

Correct : B. propeller fans

32. Why is induced draught considered better than the forced draught?

Correct : A. because power requirement is high for forced draught

33. Nozzles are used to control the ___________

Correct : B. rate of flow

34. A nozzle used to send fluid in coherent stream is called as ________

Correct : A. jet

35. In fountains the type of nozzle used is _______

Correct : D. laminar jet

36. Nozzles used in blast furnaces are called as _______

Correct : C. tuyeres

37. If mach number is less than one then its flow is ______________

Correct : A. subsonic flow

38. Nozzle used in rocket engine is __________

Correct : C. convergent – divergent nozzle

39. In rocket engine the flow in the throat of the nozzle is __________

Correct : A. subsonic

40. When mach number is greater than one the flow is ________

Correct : B. supersonic

41. In rocket engines the amount of expansion in Nozzle determines the __________

Correct : C. exit temperature & pressure

42. Pressure ratios below 20 are used in _____________ engines.

Correct : C. heavy frame engines

43. Aeroderivative engines have pressure ratios ___________

Correct : A. greater than 30

44. Aeroderivative engines are used where ____________ power units are required.

Correct : B. smaller

45. Gas turbines operate at pressures ________ than critical pressure ratio.

Correct : B. lesser

46. Critical pressure ratio is ratios of pressures at _________ discharge.

Correct : D. maximum

47. Coefficient of velocity of nozzle is _______________

Correct : B. actual velocity/theoretical velocity

48. Coefficient of discharge of Nozzle is _______

Correct : B. cd = cc*cv

49. Coefficient of contraction is the__________

Correct : A. ratio of actual cross sectional area to geometric cross sectional area

50. Pressure loss occurs in nozzle due to __________

Correct : C. frictional forces

51. Head loss in nozzles occurs due to __________

Correct : A. pipes head loss

52. At vena contracta the velocity is _________ and pressure is ___________

Correct : C. highest, lowest

53. When flow converts from supersonic to subsonic then __________ is produced.

Correct : A. shock wave

54. Shock wave causes instantaneous _________ to the subsonic speed.

Correct : B. decrease

55. Mixture of steam and liquid water is called as _________

Correct : B. wet steam

56. Supersaturated steam is also called as _________

Correct : C. two phase mix

57. If heat is added to the wet steam temperature _________

Correct : C. raises after sometime

58. After steam bubbles break the water surface, they carry water droplets this is called as ________

Correct : A. entrainment

59. Entrainment happens at __________

Correct : B. outlet of the boiler

60. Resistance of water dominating the steam is called as _______

Correct : B. erosion

61. When steam is transported dryness fraction _________

Correct : B. decreases

62. Coefficient of discharge is the __________ of Actual discharge to the theoretical discharge.

Correct : A. ratio

63. Coefficient of discharge is used to measure ___________

Correct : D. resistance offered by the nozzle

64. Unit of flow resistance is _________

Correct : D. no unit

65. Coefficient of discharge is the ____________

Correct : A. product of coefficient of velocity and coefficient of contraction

66. Coefficient of discharge is _____________

Correct : B. inversely proportional to square of the coefficient of discharge

67. For sharp edge orifice, coefficient of discharge lies between ___________

Correct : A. 0.61 – 0.64

68. In the equation Cd=1/K(0.5) what does K mean ?

Correct : C. flow resistance

69. A turbine having alternate blades and nozzles is called as _______________

Correct : A. impulse turbine

70. Multi stage arrangement of turbines is called as __________

Correct : C. compounding

71. Compounding __________ efficiency at low speed.

Correct : B. increase

72. In velocity compounded turbines flow passage is from ____________

Correct : D. none of the mentioned

73. A velocity compounded impulse turbine is also called as __________

Correct : A. curtis wheel

74. Reaction turbine is also called as _________

Correct : C. parsons turbine

75. Compounding is used for _________ power applications.

Correct : B. high

76. Which type of boiler is it when the furnace is placed in the region of boiling water?

Correct : A. internally fired boiler

77. What type of boiler is a Lamont boiler?

Correct : A. forced circulation

78. What is called as the heart of the Lamont boiler?

Correct : B. centrifugal pump

79. In what form are the boiler’s tube arrange in Lamont boiler?

Correct : C. parallel in horizontal

80. Through which does the even circulation of feed water is possible in Lamont boiler?

Correct : A. nozzles

81. What is the pressure range between which Lamont boilers operates?

Correct : B. 120-160bar

82. What type of steam is generated by evaporator tube of Lamont boiler?

Correct : A. saturated steam

83. What is the main disadvantage of Lamont boiler?

Correct : C. formation of bubbles

84. What type of boiler is a Benson boiler?

Correct : A. super critical boiler

85. What is the capacity of Benson boiler?

Correct : B. 150 tonnes/hr & above

86. What is the major disadvantage of the Benson boilers?

Correct : C. deposition of salts

87. Why starting valve is closed and valve 2 is opened while taking boiler on range in Benson boiler?

Correct : A. avoid excessive heating of tube

88. What is the function of boiler?

Correct : C. to generate steam at constant pressure

89. Why single boiler unit per turbine is equipped commonly?

Correct : A. for better turbine control

90. How can be the plant efficiency of steam power plant is increased?

Correct : A. by using high pressure and high temperature steam

91. What is the temperature at which the steam boilers are capable to withstand?

Correct : C. 540oc

92. What is needed to be increased to increase the heat transfer rate in the boiler?

Correct : C. water velocities

93. In what is water in high pressure boiler circulated through?

Correct : D. tubes

94. Where is water steam separator drum located in Lamont boiler?

Correct : D. outside of boiler

95. Which of the given boilers velocity of flue gases is greater than velocity of sound?

Correct : D. velox boiler

96. Which boiler is most successful boiler in the gas turbine industries?

Correct : D. can increase heat transfer without changing its size

97. What type of boiler is a Velox boiler?

Correct : A. forced circulation boiler

98. What is used to heat the feed water which is used for recirculation through tubes?

Correct : C. economizer

99. How many circuits are there in the Schmidt-Hartmann boiler?

Correct : B. 2

100. Which type of circulation is incurred in Schmidt-Hartmann boiler?

Correct : A. natural circulation