Quiznetik

Fluid Mechanics (FM) | Set 7

1. The depth of buckets of Pelton wheel

Correct : A. 1.2 times diameter of jet

2. The ratio of pitch diameter of Pelton wheel to diameter of jet is known as

Correct : B. Jet ratio

3. Find the diameter of jet D, if jet ratio m and diameter of jet d are given as 10 and 125mm.

Correct : A. 1.25 meters

4. The number of buckets of Pelton wheel is 25 and diameter of runner is 1.5meters then calculate diameter of jet is

Correct : B. 85mm

5. In most of cases the value of jet ratio is

Correct : C. 12

6. Number of buckets on runner of Pelton wheel is given by expression? (D-diameter of runner and d- diameter of jet)

Correct : A. 15 + D/2d

7. is obtained by dividing total rate of flow through the turbine by rate of flow through single jet.

Correct : A. Number of jets

8. If diameter of jet is 85mm and diameter of runner is 1.5 meter then calculate width of buckets.

Correct : D. 425mm

9. If diameter of jet is 85mm and diameter of runner is 1.5 meter then depth of buckets is

Correct : D. 102mm

10. If diameter of jet is 85mm and diameter of runner is 1.5 meter then calculate number of buckets on Pelton wheel approximately

Correct : D. 25

11. Radial flow reaction turbines are those turbines in which water flows

Correct : A. Radial direction

12. Main parts of radial flow reaction turbines are

Correct : D. All of the mentioned

13. Radial flow reaction turbines contain spiral casing which area

Correct : B. Gradually decreases

14. consists of stationary circular wheel all around the runner of turbine

Correct : B. Guide mechanism

15. The casing of radial flow reaction turbine is made of spiral shape, so that water may enter the runner

Correct : D. Constant velocity

16. allow the water to strike the vanes fixed on runner without shock at inlet

Correct : B. Guide vanes

17. Runner blades are made up of

Correct : A. Cast steel

18. The pressure at the exit of runner of reaction turbine is generally than atmospheric pressure

Correct : B. Lesser

19. is a pipe of gradually increasing area used for discharging water from exit of the turbine to the tail race

Correct : C. Draft tube

20. and of radial flow reaction turbine are always full of water.

Correct : A. Casing and runner

21. governs the flow of water entering the runner blades.

Correct : B. Guide vanes

22. Inward radial flow reaction turbine is a turbine in which water flows across the blades of runner_

Correct : B. Radially inward

23. Which of following is inward radial flow reaction turbine?

Correct : B. Francis turbine

24. In Inward radial flow reaction turbine which is not required?

Correct : D. Breaking jet

25. The main difference between reaction turbine and inward radial flow reaction turbine is water flows

Correct : B. Radially inward

26. In Inward radial flow reaction turbine the ratio of tangential wheel at inlet to given velocity of jet is known as

Correct : B. Flow ratio

27. In Inward radial flow reaction turbine the ratio of tangential velocity at inlet to the given velocity

Correct : A. Speed ratio

28. In Inward radial flow reaction turbine if angle made by absolute velocity with its tangent is 90 degrees and component of whirl is zero at outlet is

Correct : B. Radial outlet discharge

29. In which of following turbine whirl component is zero?

Correct : B. Inward radial flow reaction turbine

30. Discharge in inward flow reaction turbine

Correct : B. Decreases

31. Speed control of Outward flow reaction turbine is

Correct : B. Moderate

32. Centrifugal head in inward flow reaction turbine

Correct : B. Decreases

33. Tendency of wheel to race is almost nil in turbine

Correct : A. Inward flow reaction turbine

34. The formation of vapour cavities is called

Correct : B. Cavitation

35. What is the degree of reaction denoted as?

Correct : B. R

36. Voids are created due to

Correct : C. Liquid free layers

37. Cavitation usually occurs due to the changes in

Correct : A. Pressure

38. Degree of reactions are most commonly used in

Correct : A. Turbomachinery

39. At high pressure, the voids can generate

Correct : C. Shock waves

40. Voids that implode near metal surface develops a

Correct : B. Cyclic stress

41. In case of gas turbines and compressors, degree of reaction is

Correct : C. Isentropic enthalpy drop in rotor/ isentropic enthalpy drop in stage

42. The velocities of the blade angles can be found out using

Correct : C. Velocity triangles

43. Which among the following velocities cannot be found using the velocity triangle?

Correct : D. Parabolic

44. Hydrodynamic cavitation is due to the process of

Correct : A. Vaporisation

45. The process of bubble generation leads to

Correct : C. High energy densities

46. Degree of reaction turbine is the ratio of?

Correct : A. Pressure energy to total energy

47. Which of these options are best suited for the total energy change inside the runner per unit weight?

Correct : B. Degree of reaction

48. Which of these ratios are termed to be hydraulic efficiency?

Correct : D. Runner power to water power

49. When a container containing a liquid is rotated, then due to centrifugal action, then which of these energies are changed?

Correct : B. Pressure energy

50. For an actual reaction turbine, what should be the angle beta, such that the loss of kinetic energy at the outlet is to be minimum?

Correct : A. 90

51. Discharge through a reaction flow reaction turbine is given by, Q =

Correct : A. Pi*d*b*Vf1

52. When the thicknesses of vanes are to be considered in the discharge of a turbine, what will be the area under consideration?

Correct : A. Pi*d – n*t

53. means the angle made by absolute velocity with the tangent on the wheel is 90 degrees and the component of whirl velocity is zero.

Correct : D. Radial discharge

54. In a Francis turbine, degree of reaction lies between

Correct : A. 0 and 1

55. The water from penstocks enters the which is spiral in shape which the area of cross section of casing goes on decreasing gradually

Correct : C. casing

56. If the water flows from inwards to outwards, the turbine is known as

Correct : D. Outward flow turbine

57. In general, reaction turbines consist of which types of energies?

Correct : C. kinetic energy and pressure energy

58. is a circular wheel on which a series of smooth, radial curved vanes are fixed.

Correct : B. Runner

59. In an outward radial flow reaction turbine the ratio of tangential wheel at inlet to given velocity of jet is known as

Correct : B. Flow ratio

60. In an outward radial flow reaction turbine the ratio of tangential velocity at inlet to the given velocity is

Correct : A. Speed ratio

61. Discharge in an outward flow reaction turbine

Correct : A. Increases

62. An outward radial reaction turbine has

Correct : A. u1 < u2

63. An outward flow reaction turbine,

Correct : B. D1 < D2

64. is ratio of pressure energy change inside runner to total energy change inside runner

Correct : A. Degree of reaction

65. Degree of reaction for impulse turbine

Correct : A. 0

66. Degree of reaction for reaction turbine is

Correct : A. 1- cot x /2(cot x –cot y )

67. A turbine is a

Correct : A. Rotary mechanical device

68. Turbine converts

Correct : B. Energy to work

69. Turbine extracts energy from

Correct : C. Fluid flow

70. Inward flow reaction turbine enter through

Correct : A. Outer periphery

71. A turbine is a

Correct : A. Turbomachinery

72. Centrifugal flow is imparted when the_

Correct : C. Efficiency is 100 percent

73. Where is the turbine not used?

Correct : A. Solar power

74. In an inward flow reaction turbine the discharge

Correct : B. Decreases

75. In impulse turbines with moving blades, there is no in blades of the turbine.

Correct : A. Pressure change

76. In impulse turbines with stationary blades, there is in blades of the turbine.

Correct : A. Pressure change

77. In an outward flow reaction turbine the discharge

Correct : A. Increases

78. Before reaching the turbine, the acceleration of the fluid takes place through the

Correct : B. Nozzle

79. The Pelton wheel extracts energy from

Correct : B. Moving fluid

80. The outward radial flow reaction turbine is a turbine in which direction of water flow is

Correct : C. Radially outward

81. The energy available at inlet for outward reaction flow turbine is

Correct : D. Pressure energy and Kinetic energy

82. Centrifugal head in Outward flow reaction turbine

Correct : A. Increases

83. Discharge in outward flow reaction turbine

Correct : A. Increases

84. Speed control of Outward flow reaction turbine is

Correct : D. Very difficult

85. Tendency of wheel to race is predominant in turbine

Correct : B. Outward flow reaction turbine

86. Outward flow reaction turbine will quite suitable for_

Correct : B. Medium head

87. In outward flow reaction turbine tangential velocity at inlet is always_ than outlet velocity.

Correct : B. Less

88. In outward radial flow reaction turbine if angle made by absolute velocity with its tangent is 90 degrees and component of whirl is zero at inlet is

Correct : A. Radial inlet discharge

89. The main difference between reaction turbine and outward radial flow reaction turbine is water flows

Correct : B. Radially inward

90. In outward radial flow reaction turbine the ratio of tangential wheel at inlet to given velocity of jet is known as

Correct : B. Flow ratio

91. Conical diffuser draft tube is also called

Correct : A. Straight divergent tube

92. The simple elbow draft tube is placed close to the_

Correct : B. Tail race

93. Turbine that consists of moving nozzles and with fixed nozzles is called as

Correct : D. Reaction turbine

94. An example of reaction turbine is_

Correct : A. Parsons turbine

95. When we arrange turbine blades in multiple stages it is called

Correct : C. Compounding

96. Compounding is needed to

Correct : D. Increase efficiency

97. Which among the following is not a type of compounding?

Correct : B. Temperature

98. Newtons second law describes the transfer of energy through impulse turbines.

Correct : A. True

99. Inner radial flow extracts energy from

Correct : B. Moving fluid

100. Reaction turbines develop torque by reacting to the gas or fluids pressure or mass.

Correct : A. True