Quiznetik

Hydraulics and Fluid Mechanics | Set 2

1. Unit of surface tension is

Correct : A. Energy/unit area

2. A Piezometer tube is used only for measuring

Correct : C. Moderate pressure

3. The Cipoletti weir is a __________ weir.

Correct : C. Trapezoidal

4. Pressure of the order of 10" torr can be measured by

Correct : D. Lonisation gauge

5. The volume of a fluid __________ as the pressure increases.

Correct : B. Decreases

6. Buoyant force is

Correct : B. The resultant force on a body due to the fluid surrounding it

7. A flow through a long pipe at decreasing rate is called __________ uniform flow.

Correct : B. Unsteady

8. Choose the wrong statement

Correct : D. All floating bodies are stable

9. The intensity of pressure at any point, in a liquid, is __________ to the depth of liquid from the surface.

Correct : B. Directly proportional

10. The discharge in an open channel corresponding to critical depth is

Correct : C. Maximum

11. A piece of wood having weight 5 kg floats in water with 60% of its volume under the liquid. The specific gravity of wood is

Correct : B. 0.6

12. A pitot tube is used to measure the

Correct : A. Velocity of flow at the required point in a pipe

13. The total energy of each particle at various places in the case of perfect incompressible fluid flowing in continuous stream

Correct : C. Remain constant

14. The critical depth meter is used to measure

Correct : C. Hydraulic jump

15. Two pipe systems can be said to be equivalent, when the following quantities are same

Correct : A. Friction loss and flow

16. In a footstep bearing, if the radius of the shaft is doubled, then the torque required to overcome the viscous resistance will be

Correct : D. Sixteen times

17. The value of bulk modulus of a fluid is required to determine

Correct : C. Mach number

18. Fluid is a substance which offers no resistance to change of

Correct : C. Shape

19. The pressure less than atmospheric pressure is known as

Correct : D. All of these

20. The normal stress in a fluid will be constant in all directions at a point only if

Correct : D. It is at rest

21. The power transmitted through a pipe is (where w = Specific weight in N/m3, and Q = Discharge in m3/s)

Correct : C. w × Q (H - hf)

22. A compound pipe is required to be replaced by a new pipe. The two pipes are said to be equivalent, if

Correct : C. Loss of head and discharge of both the pipes is same

23. The center of gravity of the volume of the liquid displaced by an immersed body is called

Correct : C. Center of buoyancy

24. A flow is called sub-sonic, if the Mach number is

Correct : A. Less than unity

25. Barometer is used to measure

Correct : B. Atmospheric pressure

26. The center of pressure of a surface subjected to fluid pressure is the point

Correct : A. On the surface at which resultant pressure acts

27. The variation in the volume of a liquid with the variation of pressure is called its

Correct : B. Compressibility

28. The surface tension of mercury at normal temperature is __________ that of water.

Correct : C. Higher than

29. Flow of water in a pipe about 3 metres in diameter can be measured by

Correct : D. Pitot tube

30. According to Francis formula, the discharge over a rectangular weir is (where n = Number of end contractions)

Correct : B. (2/3) × Cd (L - 0.1nH) × × H3/2

31. The equation of continuity holds good when the flow

Correct : D. All of the above

32. A thick liquid like syrup has a __________ viscosity than a light liquid like water.

Correct : B. Greater

33. Cavitation will begin when

Correct : A. The pressure at any location reaches an absolute pressure equal to the saturated vapour pressure of the liquid

34. When a liquid is flowing through a pipe, the velocity of the liquid is

Correct : A. Maximum at the centre and minimum near the walls

35. The velocity through a channel of circular section will be maximum when the depth of water is __________ the diameter of the circular channel.

Correct : C. 0.81 times

36. Resultant pressure of the liquid in the case of an immersed body acts through

Correct : B. Centre of pressure

37. A fluid is said to be ideal, if it is

Correct : D. Inviscous and incompressible

38. In a depressed nappe

Correct : B. The pressure below the nappe is negative

39. The value of the coefficient of compressibility for water at ordinary pressure and temperature in kg/cm is equal to

Correct : D. 21,000

40. In one dimensional flow, the flow

Correct : B. Takes place in straight line

41. To avoid vaporisation in the pipe line, the pipe line over the ridge is laid such that it is not more than

Correct : B. 6.4 m above the hydraulic gradient

42. The loss of head at exit of a pipe is (where v = Velocity of liquid in the pipe)

Correct : A. v²/2g

43. Metacentre is the point of intersection of

Correct : B. Buoyant force and the center line of body

44. The imaginary line drawn in the fluid in such a way that the tangent to any point gives the direction of motion at that point, is known as

Correct : B. Stream line

45. An open vessel of water is accelerated up an inclined plane. The free water surface will

Correct : C. Make an angle in opposite direction to inclination of inclined plane

46. The discharge over a rectangular notch is

Correct : B. Directly proportional to H3/2

47. The flow in which each liquid particle has a definite path and their paths do not cross each other is called

Correct : B. Streamline flow

48. The magnitude of water hammer depends upon the

Correct : D. All of the above

49. The fluid forces considered in the Navier Stokes equation are

Correct : A. Gravity, pressure and viscous

50. Cavitation is caused by

Correct : D. Low pressure

51. A vertical wall is subjected to a pressure due to one kind of liquid, on one of its sides. The total pressure on the wall acts at a distance __________ from the liquid surface.

Correct : C. 2H/3

52. An ideal flow of any fluid must fulfill the following

Correct : D. Continuity equation

53. The flow in a pipe or channel is said to be uniform when

Correct : A. The liquid particles at all sections have the same velocities

54. Surface tension

Correct : A. Acts in the plane of the interface normal to any line in the surface

55. Select the wrong statement

Correct : D. The diameter of an equivalent pipe is equal to that of a compound pipe

56. manometers because Alcohol is used in

Correct : D. It can provide longer column due to low density

57. If no resistance is encountered by displacement, such a substance is known as

Correct : D. Ideal fluid

58. The kinematic viscosity is the

Correct : A. Ratio of absolute viscosity to the density of the liquid

59. The viscosity of water is __________ than that of mercury.

Correct : A. Higher

60. Surface energy per unit area of a surface is numerically equal to

Correct : B. Surface tension

61. The specific weight of sea water is __________ that of pure water.

Correct : C. More than

62. Which of the following instruments is used to measure flow on the application of Bernoulli's theorem?

Correct : D. All of the above

63. The depth of the centre of pressure on a vertical rectangular gate 8 m wide and 6 m high, when the water surface coincides with the top of the gate, is

Correct : B. 3.0 m

64. An internal mouthpiece is said to be running free if the length of the mouthpiece is __________ the diameter of the orifice.

Correct : C. Less than three times

65. An ideal flow of any fluid must satisfy

Correct : D. Continuity equation

66. The height of a water column equivalent to a pressure of 0.15 MPa is

Correct : A. 15.3 m

67. The region between the separation streamline and the boundary surface of the solid body is known as

Correct : A. Wake

68. Froude number is significant in

Correct : C. Simultaneous motion through two fluids where there is a surface of discontinuity, gravity forces, and wave making effect, as with ship's hulls

69. The ratio of specific weight of a liquid to the specific weight of pure water at a standard temperature is called

Correct : B. Specific gravity of liquid

70. A hydraulic press has a ram of 15 cm diameter and plunger of 1.5 cm. It is required to lift a weight of 1 tonne. The force required on plunger is equal to

Correct : A. 10 kg

71. The total head of a liquid particle in motion is equal to

Correct : A. Pressure head + kinetic head + potential head

72. Free surface of a liquid tends to contract to the smallest possible area due to force of

Correct : A. Surface tension

73. The Metacentric heights of two floating bodies A and B are 1 m and 1.5 m respectively. Select the correct statement.

Correct : C. The body B is more stable than body A

74. The rise or depression of liquid in a tube due to surface tension will increase in size of tube will

Correct : D. Decrease

75. The total pressure on a horizontally immersed surface is (where w = Specific weight of the liquid, A = Area of the immersed surface, and x = Depth of the centre of gravity of the immersed surface from the liquid surface)

Correct : C. wAx

76. The discharge of a depressed nappe is 6 to 7 percent __________ that of a free nappe.

Correct : B. More than

77. The line of action of the buoyant force acts through the Centroid of the

Correct : D. Displaced volume of the fluid

78. The intensity of pressure at any point, in a liquid, is

Correct : B. Directly proportional to the depth of liquid from the surface

79. During the opening of a valve in a pipe line, the flow is

Correct : B. Unsteady

80. A manometer is used to measure

Correct : B. Pressure in pipes and channels

81. For hypersonic flow, the Mach number is

Correct : D. Greater than 4

82. The theoretical velocity of jet at vena contracta is (where H = Head of water at vena contracta)

Correct : D. 2gh)

83. For pipes, laminar flow occurs when Reynolds number is

Correct : A. Less than 2000

84. When the flow in an open channel is gradually varied, the flow is said to be

Correct : B. Steady non-uniform flow

85. In an internal mouthpiece, if the jet after contraction does not touch the sides of the mouthpiece, then the mouthpiece is said to be

Correct : B. Running free

86. The units of kinematic viscosity are

Correct : A. Metres² per sec

87. The length of a liquid stream while flowing over a weir __________ at the ends of the sill.

Correct : C. Contracts

88. Newton's law of viscosity is a relationship between

Correct : A. Shear stress and the rate of angular distortion

89. The total energy line lies over the hydraulic gradient line by an amount equal to the

Correct : B. Velocity head

90. Choose the wrong statement

Correct : D. The vertical component passes through the center of pressure of the volume

91. In open channels, the specific energy is the

Correct : B. Total energy measured with respect to the datum passing through the bottom of the channel

92. For a floating body to be in stable equilibrium, its metacentre should be

Correct : D. Above the center of gravity

93. A water tank contains 1.3 m deep water. The pressure exerted by the water per metre length of the tank is

Correct : B. 8.29 kN

94. Total pressure on a lmxlm gate immersed vertically at a depth of 2 m below the free water surface will be

Correct : A. 1000 kg

95. If a body floating in a liquid occupies a new position and remains at rest in this new position, when given a small angular displacement, the body is said to be in __________ equilibrium.

Correct : A. Neutral

96. A streamline is defined as the line

Correct : C. Of equal velocity in a flow

97. The flow in a pipe or channel is said to be non-uniform when

Correct : B. The liquid particles at different sections have different velocities

98. Hydrometer is used to determine

Correct : A. Specific gravity of liquids

99. The dynamic viscosity of the liquid __________ with rise in temperature.

Correct : C. Decreases

100. For pipes, turbulent flow occurs when Reynolds number is

Correct : C. More than 4000