Quiznetik
Fluid Mechanics (FM) | Set 9
1. The draft tube at the exit of the nozzle increases the
A. Temperature
B. Pressure
C. Volume of the flow
D. Density of flow
Correct : B. Pressure
2. Efficiency of a draft tube gives
A. Temperature difference
B. Pressure difference
C. Kinetic energy difference
D. Density of flow
Correct : C. Kinetic energy difference
3. Cavitation in a draft tube occurs when
A. Temperature difference
B. Pressure drop
C. Kinetic energy difference
D. Density of flow
Correct : B. Pressure drop
4. Which among the following is an important parameter to avoid cavitation?
A. Tail race length
B. Head race length
C. Height of draft tube
D. Pump
Correct : C. Height of draft tube
5. The draft tube is situated in the
A. Inlet
B. Outlet
C. Tank
D. Nozzle
Correct : B. Outlet
6. Which equation is applied to determine the flow?
A. Newtons equation
B. Rutherford’s equation
C. Bernoulli’s equation
D. Faradays equation
Correct : C. Bernoulli’s equation
7. Height of the draft tube is denoted by
A. H
B. h
C. z
D. x
Correct : C. z
8. Draft tube allows turbine to be placed above the tail race.
A. True
B. False
C. none
D. none
Correct : A. True
9. The efficiency of the draft tube depends on the
A. Heat
B. Pressure
C. Temperature
D. Pressure and temperature
Correct : D. Pressure and temperature
10. Draft tubes have shafts
A. Horizontal
B. Vertical
C. Circular
D. Cross sectional
Correct : B. Vertical
11. Draft tubes are situated at the outlet in
A. Pelton
B. Reaction
C. Kaplan
D. Francis
Correct : A. Pelton
12. Efficiency of a draft tube is directly proportional to its
A. Temperature
B. Pressure
C. Velocity
D. Density
Correct : C. Velocity
13. Z is a draft tube is
A. Temperature difference
B. Pressure drop
C. Kinetic energy difference
D. Datum head
Correct : D. Datum head
14. Draft tube operates at
A. Same efficiency
B. Different efficiency
C. Turbine
D. Pump
Correct : A. Same efficiency
15. The draft tube is an
A. Interior tube
B. Exterior tube
C. Tank depth alternator
D. Nozzle tube
Correct : B. Exterior tube
16. What type of pressure does the draft tube depend upon?
A. Gauge pressure
B. Atm pressure
C. Normal pressure
D. Normal and Atm pressure
Correct : A. Gauge pressure
17. Gauge pressure of the draft tube is denoted by
A. P
B. h
C. z
D. x
Correct : A. P
18. Draft tube allows turbine to be placed below the tail race.
A. True
B. False
C. none
D. none
Correct : B. False
19. Specific speed is denoted by
A. N
B. n
C. Ns
D. S
Correct : C. Ns
20. Specific speeds are used in pumps to determine
A. Temperature
B. Reaction speed
C. Suction specific speed
D. Wheel speed
Correct : C. Suction specific speed
21. The tube at the exit of the nozzle increases the
A. Temperature
B. Pressure
C. Volume of the flow
D. Density of flow
Correct : B. Pressure
22. Specific speed is used to characterize
A. Turbomachinery speed
B. Flow speed
C. Energy flow
D. Heat generated
Correct : A. Turbomachinery speed
23. Specific speed predicts the shape of a/an
A. Pump
B. Density head
C. Impeller
D. Motor
Correct : C. Impeller
24. What helps in categorizing the impellers?
A. Quasi static number
B. Rotor
C. Height of draft tube
D. Pump
Correct : A. Quasi static number
25. Imperial units is defined as
A. Temperature by pressure
B. Tail race and head race
C. Revolutions per minute
D. Turbine performance
Correct : C. Revolutions per minute
26. Ratio of pump or turbine with reference pump or turbine is called as
A. Efficiency
B. Performance
C. Heat generated
D. Relative velocity
Correct : B. Performance
27. Low specific speed in hydraulic head is developed due to
A. Mass flow rate
B. Increase in temperature
C. Centrifugal force
D. Increase in pressure
Correct : C. Centrifugal force
28. Centrifugal pump impellers have speed ranging from
A. 500- 10000
B. 50- 100
C. 200-300
D. 0-50
Correct : A. 500- 10000
29. What is the unit of specific speed in metric system?
A. m.s
B. m/s
C. m3/s
D. m
Correct : C. m3/s
30. Specific speed develop a hydraulic flow through the centrifugal pumps.
A. True
B. False
C. none
D. none
Correct : A. True
31. Net suction speed is used in problems with cavitation.
A. True
B. False
C. none
D. none
Correct : A. True
32. The runner diameter in a turbine is denoted as
A. A
B. Dr
C. Rr
D. De
Correct : D. De
33. Specific speed is the speed of the turbine which is similar to its
A. Temperature difference
B. Pressure difference
C. Aspect ratio
D. Speed of rotor
Correct : C. Aspect ratio
34. Specific speed develops a unit power under a unit
A. Temperature
B. Pressure
C. Volume of the flow
D. Head
Correct : D. Head
35. Impeller in a motor is used to
A. Change temperatures
B. Change Pressure
C. Kinetic energy change
D. Change density
Correct : B. Change Pressure
36. Hydraulic head is also called as
A. Pressure head
B. Density head
C. Kinetic head
D. Piezometric head
Correct : D. Piezometric head
37. Specific speed of a Pelton wheel with single jet is
A. 8.5 to 30
B. 30 to 51
C. 51 to 225
D. 230 to 500
Correct : A. 8.5 to 30
38. Specific speed is an index used to predict
A. Head race distance
B. Tail race distance
C. Tank dimensions
D. Turbine performance
Correct : D. Turbine performance
39. Specific speed of a Pelton wheel with multiple jets is
A. 8.5 to 30
B. 30 to 51
C. 51 to 225
D. 230 to 500
Correct : B. 30 to 51
40. Specific speed of a Francis turbine is
A. 8.5 to 30
B. 30 to 51
C. 51 to 225
D. 230 to 500
Correct : C. 51 to 225
41. Specific speed of a Kaplan turbine is
A. 8.5 to 30
B. 30 to 51
C. 51 to 225
D. 355 to 860
Correct : D. 355 to 860
42. Specific speed less than 500 are called
A. Positive displacement pumps
B. Negative displacement pumps
C. Draft tubes
D. Tanks
Correct : A. Positive displacement pumps
43. With the increase in specific speeds,
A. Head race distance increases
B. Tail race distance increases
C. Tank dimensions increases
D. Diameters of impeller increases
Correct : D. Diameters of impeller increases
44. Specific speed is used to predict desired pump or turbine performance.
A. True
B. False
C. none
D. none
Correct : A. True
45. Once we know the desired functions of the specific speed, it is easier to calculate its components units.
A. True
B. False
C. none
D. none
Correct : A. True
46. Which among the following is not a unit quantity of turbine?
A. Unit speed
B. Unit discharge
C. Unit power
D. Unit temperature
Correct : D. Unit temperature
47. What does DMU stand for?
A. Density matter usage
B. Direct material usage
C. Density material usage
D. Depth matter usage
Correct : B. Direct material usage
48. Unit speed is the speed of the turbine operating under_
A. One-meter head
B. Pressure head
C. Volumetric head
D. Draft tube
Correct : A. One-meter head
49. One dyne is equal to N.
A. 10
B. 100
C. 1000
D. 10-5
Correct : D. 10-5
50. What is symbol for unit speed?
A. S
B. N
C. Ns
D. Nu
Correct : D. Nu
51. Unit speed of a single jet in a turbine is
A. 100 m/s
B. 300 m/s
C. 500 m/s
D. 800 m/s
Correct : D. 800 m/s
52. Unit speed is directly proportional to
A. Head race distance
B. Specific speed
C. Pressure
D. Turbine performance
Correct : B. Specific speed
53. Unit discharge is the discharge through the turbine when the head of the turbine is
A. High
B. Zero
C. Unity
D. Low
Correct : C. Unity
54. 9 Unit discharge is denoted as
A. Du
B. Qu
C. Su
D. Nu
Correct : B. Qu
55. Unit discharge is directly proportional to
A. Head race distance
B. Discharge of fluid in the turbine.
C. Pressure
D. Turbine performance
Correct : B. Discharge of fluid in the turbine.
56. Unit quantities are physical quantities
A. With numerical variables
B. Without numerical variables
C. With different sets
D. With unit difference
Correct : B. Without numerical variables
57. Dyne cm is a Torque measurement unit.
A. True
B. False
C. none
D. none
Correct : A. True
58. Unit quantities play an important role in determining the dimensional quantities.
A. True
B. False
C. none
D. none
Correct : A. True
59. Unit power is developed by the turbine when the head of the turbine is unity.
A. True
B. False
C. none
D. none
Correct : A. True
60. Constant head curves are also called as
A. Head race curves
B. Tail race curves
C. Main characteristic curves
D. Impeller curves
Correct : C. Main characteristic curves
61. The speed of the turbine in a constant head curve is varied by
A. Temperature change
B. Reaction speed change
C. Changing the gate opening
D. Wheel speed change
Correct : C. Changing the gate opening
62. Constant speed curves travel at constant speed when the value is equal to
A. 0
B. 1
C. 2
D. 3
Correct : B. 1
63. Power of a turbine is measured
A. Mechanically
B. Electrically
C. Chemically
D. Thermally
Correct : A. Mechanically
64. Which among the following is not a parameter to determine the efficiency of the turbine?
A. Unit speed
B. Unit power
C. Unit volume
D. Unit discharge
Correct : C. Unit volume
65. Which among the following is not an important parameter to determine the performance of the turbine?
A. Speed
B. Discharge
C. Head
D. Volume of tank
Correct : D. Volume of tank
66. Which among the following is not a type of curve?
A. Logarithimic curve
B. Straight curve
C. Pressure vs power
D. Efficiency vs speed
Correct : C. Pressure vs power
67. The inlet passage of water entry is controlled by
A. Head race
B. Gate
C. Tail race
D. Pump
Correct : B. Gate
68. Overall efficiency vs what is drawn to determine the turbine performance?
A. Unit Discharge
B. Unit speed
C. Unit power
D. Unit pressure
Correct : B. Unit speed
69. Constant discharge takes place due to
A. Unit Discharge
B. Unit speed
C. Unit power
D. Unit pressure
Correct : B. Unit speed
70. All the characteristic curves are drawn with respect to
A. Unit Discharge
B. Unit speed
C. Unit power
D. Unit pressure
Correct : B. Unit speed
71. In constant speed curves, the speed is kept a constant varying its head.
A. True
B. False
C. none
D. none
Correct : A. True
72. In all the characteristic curves, the overall efficiency is aimed at the maximum value.
A. True
B. False
C. none
D. none
Correct : A. True
73. Constant efficiency curves are plotted using
A. Constant head curves
B. Constant speed curves
C. Main characteristic curves
D. Constant speed and constant head
Correct : D. Constant speed and constant head
74. Constant speed curves are also called as
A. Main characteristic curves
B. Turbine curves
C. Tail race curves
D. Impeller curves
Correct : C. Tail race curves
75. Constant speed curve is denoted as
A. T
B. V
C. c
D. V
Correct : C. c
76. Constant speed curves are
A. Scalar quantities
B. Vector quantities
C. Constant quantities
D. Different conditions
Correct : B. Vector quantities
77. Constant speed is measured
A. Mechanically
B. Electrically
C. Chemically
D. Thermally
Correct : A. Mechanically
78. Constant speed curves are determined by the
A. Arc length
B. Power
C. Heat
D. Temperature
Correct : C. Heat
79. Which component is necessary for writing the velocity equation?
A. Cos component
B. Sine Component
C. Cos and sine component
D. Independent
Correct : C. Cos and sine component
80. Which among the following is not a shape for a curve?
A. Logarithmic curve
B. Helix curve
C. Straight curve
D. Speed curve
Correct : D. Speed curve
81. How do we plot points in a curve?
A. Analytical approach
B. General approach
C. Tail approach
D. Head approach
Correct : A. Analytical approach
82. Plotting sine curve will take place along the
A. y axis
B. x axis
C. z axis
D. x and z
Correct : B. x axis
83. In analytical approach, dp=
A. vdt
B. v
C. dt
D. dx
Correct : A. vdt
84. The equation is general approach is called as central difference.
A. True
B. False
C. none
D. none
Correct : A. True
85. The approximate value of the constant speed curve is given by ratio of
A. dy/dp
B. dx/dp
C. dt/dx
D. dt/dy
Correct : A. dy/dp
86. In constant speed curves, the velocity is kept a constant varying its head.
A. True
B. False
C. none
D. none
Correct : B. False
87. The performance of a characteristic curve is kept at a high value.
A. True
B. False
C. none
D. none
Correct : A. True
88. In nozzle governing, the flow rate of steam is regulated by
A. Nozzles
B. Pumping
C. Drafting
D. Intercooling
Correct : A. Nozzles
89. The flow rate of steam is controlled by regulating the
A. Steam
B. Pressure
C. Temperature
D. Speed
Correct : B. Pressure
90. What is primary objective of steam turbine governing?
A. Maintain constant speed
B. Maintain constant pressure
C. Maintain constant temperature
D. Maintain constant expansion
Correct : A. Maintain constant speed
91. What is the purpose of a steam turbine governing?
A. Controls speed
B. Controls flow rate
C. Controls volume
D. Controls discharge
Correct : B. Controls flow rate
92. The advantage of nozzle governing is that no regulating pressure is applied.
A. True
B. False
C. none
D. none
Correct : A. True
93. During the steam turbine governing, what remains a constant?
A. Speed of rotation
B. Flow rate
C. Pump head
D. Volume of fluid
Correct : A. Speed of rotation
94. When do we apply by pass governing?
A. When turbine is overloaded
B. When Unit speed decreases
C. When Unit power increases
D. When Unit pressure decreases
Correct : A. When turbine is overloaded
95. When bypass valve is opened to
A. Increase Pressure
B. Increase Unit speed
C. Increase Unit power
D. Increase the amount of fresh steam
Correct : D. Increase the amount of fresh steam
96. What is the unit of steam rate?
A. kg
B. kg/m
C. kg/kWh
D. N/m
Correct : C. kg/kWh
97. With the increase in load, Energy in the turbine
A. Decreases
B. Increases
C. Remains same
D. Independent
Correct : A. Decreases
98. Combination governing involves usage of two or more governing.
A. True
B. False
C. none
D. none
Correct : A. True
99. When the mechanical speed of the shaft increases beyond 110 percent, we use
A. Throttle governing
B. Steam governing
C. Nozzle governing
D. Emergency governing
Correct : D. Emergency governing
100. When the balancing of the turbine is disturbed, we use
A. Throttle governing
B. Steam governing
C. Nozzle governing
D. Emergency governing
Correct : D. Emergency governing