hydraulics and fluid mechanics Mcqs
51. The resultant upward pressure of the fluid on an immersed body is called_________________?
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A. center of pressure

B. upthrust

C. buoyancy

D. all the above are correct

E. none of above is correct

52. Which of the following is the unit of kinematic viscosity _________________?
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A. none of the above

B. stoke

C. poise

D. faraday

E. pascal

53. The volumetric change of the fluid caused by a resistance is known as_________________?
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A. adhesion

B. compressibility

C. cohesion

D. volumetric index

E. volumetric strain

54. Surface tension _____________________?
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A. is a function of the curvature of the interface

B. is also known as capillarity

C. acts in the plane of the interface normal to any line in the surface

D. decreases with fall in temperature

E. has no units

55. The units of viscosity are__________________?
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A. kg sec/metre

B. none of the above

C. newton-sec per metre

D. metres2 per sec

E. newton-sec per metre2

56. Choose the correct relationship_________________?
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A. hydrostaticforce = surface tension x gravity.

B. specific gravity = gravity x density

C. kinematicviscosity = dynamicviscosity x density

D. dynamicviscosity = kinematicviscosity x density

E. gravity = specific gravity x density

57. For manometer, a better liquid combination is one having______________?
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A. surface tension is no criterion

B. high density and viscosity

C. low density and viscosity

D. lower surface tension

E. higher surface tension
58. The surface tension of mercury at normal temperature compared to that of water is____________________?
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A. less

B. more

C. more or less depending on size of glass tube

D. none of the above.

E. same

59. A fluid in equilibrium cant sustain_________________?
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A. compressive stress

B. all of the above

C. bending stress

D. shear stress

E. tensile stress

60. An ideal flow of any fluid must satisfy ___________________?
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A. continuity equation

B. Bernoullis theorem

C. boundary layer theory

D. Newtons law of viscosity

E. Pascal law

61. Rain drops are spherical because of____________________?
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A. viscosity

B. atmospheric pressure

C. none of the above

D. air resistance

E. surface tension forces
62. The rise or depression of liquid in a tube due to surface tension wim increase in size of tube will_______________?
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A. increase

B. decrease

C. unpredictable

D. remain unaffected

E. may increase or decrease depending on the characteristics of liquid

63. Which of the following manometer has highest sensitivity __________________?
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A. U-tube with mercury

B. U-tube with water

C. inclined U-tube

D. micro-manometer with water

E. displacement type

64. Eulers dimensionless number relates the following_______________?
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A. viscous force and buoyancy force

B. pressure force and inertial force

C. viscous force and inertial force

D. pressure force and viscous force

E. inertial force and gravity

66. To avoid an interruption in the flow of a syphon, an air vessel is provided______________?
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A. at the summit

B. none of the above

C. at the outlet

D. at the inlet

E. ay nay point between inlet and outlet

67. The vapour pressure over the concave surface is__________________?
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A. less man the vapour pressure over the plane surface

B. greater than the vapour pressure over the plane surface

C. zero

D. none of the above

E. equal to the vapour pressure over the plane surface

68. The flow in which conditions do not change with time at any point, is known as _____________________?
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A. uniform flow

B. steady flow

C. streamline flow

D. one dimensional flow

E. turbulent flow

70. Two dimensional flow occurs when___________________?
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A. velocity, depth, pressure, etc. change from point to point in the fluid flow

B. the fluid particles move in plane or parallel planes and the streamline pat-terns are identical in each plane

C. the velocity of successive fluid par-ticles, at any point, is the same at suc-cessive periods of time

D. the direction and magnitude of the velocity at all points are identical

E. the magnitude and direction of the velocity do not change from point to point in the fluid

71. When a body floating in a liquid, is displaced slightly, it oscillates about ___________________?
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A. center of pressure

B. center of buoyancy

C. liquid surface

D. e.g. of body

E. metacentre
72. Choose the wrong statement ?
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A. If e.g. and center of buoyancy coincide, the submerged body must lie at neutral equilibrium for all positions

B. All floating bodies are stable

C. The center of buoyancy is located at the center of gravity of the displaced liquid

D. For stability of a submerged body, the center of gravity of body must lie directly below the center of buoyancy

E. For stability of floating cylinders or spheres, the e.g. of body must lie below the center of buoyancy

73. Uniform flow occurs when____________________?
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A. size and shape of the cross section in a particular length remain constant

B. the flow is steady

C. flow occurs at constant fate

D. the flow is streamline

E. size and cross section change uniformly along length

75. General energy equation holds for_________________?
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A. laminar flow

B. steady flow

C. turbulent flow

D. all of the above

E. non-uniform flow
76. The horizontal component of buoyant force is__________________?
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A. negligible

B. zero

C. same as buoyant force

D. non of these

77. A liquid would wet the solid, if adhesion forces as compared to cohesion forces are_________________?
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A. equal

B. more

C. less

D. there is no such criterion

E. less at low temperature and more at high temperature

79. A pressure of 25 m of head of water is equal to________________?
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A. 25 kN/m2

B. 2500 kN/m2

C. 245 kN/m2

D. 12.5 kN/m2

E. 2.5kN/m2

80. Pressure of the order of 10? torr can be measured by_______________ ?
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A. McLeod gauge

B. Bourdon tube

C. micro-manometer

D. Pirani Gauge

E. ionisastion gauge
81. Newtons law of viscosity is a relationship between________________?
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A. shear stress and viscosity

B. shear stress anctthejiate of angular distortion

C. pressure, velocity and viscosity

D. shear stress, pressure and rate of angular distortion

E. shear stress, velocity and viscosity

83. The vapour pressure over the concave surface is________________?
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A. zero

B. greater than the vapour pressure over the plane surface

C. less man the vapour pressure over the plane surface

D. equal to the vapour pressure over the plane surface

E. none of the above

84. According to the principle of buoyancy a body totally or partially immersed in a fluid will be lifted up by a force equal to __________________?
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A. more than the weight of the body

B. less than the weight of the body

C. weight of the fluid displaced by the body

D. weight of body plus the weight of the fluid displaced hy the body

E. the weight of the body

85. Barometer is used to measure__________________?
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A. very low pressure

B. rain level

C. atmospheric pressure

D. pressure in pipes, channels etc.

E. difference of pressure between two points

88. For a floating body to be in equilibrium __________________?
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A. center of buoyancy and e.g. must lie on same vertical plane

B. none of the above

C. meta center should be above e.g.

D. a righting couple should be formed

E. all of the above
90. 4-61. Kinematic viscosity is equal to________________?
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A. 1/dynamicviscosity x density

B. dynamic viscosity/density

C. dynamicviscosity x density

D. density/dynamic viscosity

E. same as dynamic viscosity

92. Surface energy per unit area of a surface is numerically equal to ___________________?
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A. surface tension

B. force of adhesion

C. viscosity

D. atmospheric pressure

E. force of cohesion

93. Non uniform flow occurs when ____________________?
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A. velocity, depth, pressure, etc. change from point to point in the fluid flow

B. the velocity of successive fluid par-ticles, at any point, is the same at suc-cessive periods of time

C. the fluid particles move in plane or parallel planes and the streamline pat-terns are identical in each plane

D. the direction and magnitude of the velocity at all points are identical

E. the magnitude aricf direction of the velocity do not change from point to point in the fluid

95. Ratio of inertia force to surface Jension is known as ________________________?
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A. Mach number

B. Webers number

C. Froude number

D. Reynolds number

E. none of the above

96. Principle of similitude forms the basis of__________________?
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A. performing acceptance tests

B. hydraulic designs

C. comparing two identical equipments

D. designing models so that the result can be converted to prototypes

E. comparing similarity between design and actual equipment

98. The center of pressure of a surface subjected to fluid pressure is the point____________________?
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A. on the surface at which gravitational force acis

B. on the surface at which resultant pres-sure acts

C. where pressure equivalent to hydraulic thrust will act

D. similar to metacentre

E. at which all hydraulic forces meet

99. For pipes, laminar flow occurs when Roynolds number is__________________?
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A. none of the above

B. less than 4000

C. more than 4000

D. less than 2000

E. between 2000 and 4000

100. In an isothermal atmosphere, the pressure__________________?
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A. unpredictable

B. remains constant

C. decreases linearly with elevation

D. increases exponentially with elevation

E. varies in the same way as the density