Quiznetik

Fluid Mechanics (FM) | Set 3

1. Choose the wrong statement

Correct : D. When in equilibrium, fluids can sustain shear forces

2. An orifice is said to be large, if

Correct : D. The available head of liquid is less than 5 times the height of orifice

3. A piece of metal of specific gravity 13.6 is placed in mercury of specific gravity 13.6, what fraction of it volume is under mercury?

Correct : C. Whole of the metal piece will be immersed with its top surface just at mercury level

4. Dynamic viscosity of most of the liquids with rise in temperature

Correct : B. Decreases

5. Select the correct statement

Correct : B. Standard atmospheric pressure is the mean local atmospheric pressure a* sea level

6. The flow in which the particles of a fluid attain such velocities that varies from point to point in magnitude and direction as well as from instant to instant, is known as

Correct : D. Turbulent flow

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

Correct : C. More than

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

Correct : D. All of the above

9. An ideal flow of any fluid must satisfy

Correct : D. Continuity equation

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

Correct : A. 15.3 m

11. 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

12. 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

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

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

14. When the Venturimeter is inclined, then for a given flow it will show __________ reading.

Correct : A. Same

15. Cavitation is caused by

Correct : D. Low pressure

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

Correct : D. Continuity equation

17. Surface tension

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

18. Alcohol is used in manometers because

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

19. The discharge through a wholly drowned orifice is given by (where H1 = Height of water (on the upstream side) above the top of the orifice, H2 = Height of water (on the downstream side) above the bottom of the orifice, and H = Difference between two water levels on either side of the orifice)

Correct : C. Q = Cd × b (H2 - H1) × √(2gh)

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

Correct : D. Ideal fluid

21. The kinematic viscosity is the

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

22. Choose the correct relationship

Correct : B. Dynamic viscosity = kinematic viscosity × density

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

Correct : A. Higher

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

Correct : B. Surface tension

25. Free surface of a liquid behaves like a sheet and tends to contract to smallest possible area due to the

Correct : B. Force of cohesion

26. Which of the following statement is correct?

Correct : D. All of the above

27. Choose the wrong statement

Correct : D. Viscosity of liquids is appreciably affected by change in pressure

28. The unit of dynamic viscosity in S.I. units is

Correct : B. N-s/m2

29. A perfect gas

Correct : D. None of the above

30. In a static fluid

Correct : D. Only normal stresses can exist

31. One liter of water occupies a volume of

Correct : D. 1000 cm3

32. The maximum discharge over a broad crested weir is

Correct : D. 1.71 Cd × L × H3/2

33. The ratio of absolute viscosity to mass density is known as

Correct : C. Kinematic viscosity

34. Hot wire anemometer is used to measure

Correct : D. Gas velocities

35. Venturimeter is used to

Correct : C. Measure the discharge of liquid flowing in a pipe

36. The pressure measured with the help of a pressure gauge is called

Correct : B. Gauge pressure

37. In order to increase sensitivity of U-tube manometer, one leg is usually inclined by angle 'θ'. Sensitivity of inclined tube to sensitivity of U-tube is equal to

Correct : B. 1/Sinθ

38. Capillary action is due to the

Correct : D. All of the above

39. The intensity of pressure on an immersed surface __________ with the increase in depth.

Correct : B. Increases

40. Stoke is the unit of

Correct : A. Kinematic viscosity in C. G. S. units

41. The vapour pressure over the concave surface is

Correct : A. Less man the vapour pressure over the plane surface

42. Mercury is often used in barometer because

Correct : D. Both (B) and (C)

43. Gradually varied flow is

Correct : D. Steady non-uniform

44. The viscosity of water at 20°C is

Correct : D. One centipoise

45. According to Bernoulli's equation for steady ideal fluid flow

Correct : D. The energy is constant along a streamline but may vary across streamlines

46. Bernoulli equation deals with the law of conservation of

Correct : C. Energy

47. If the surface of liquid is convex, men

Correct : C. Cohesion pressure is increased

48. The atmospheric pressure with rise in altitude decreases

Correct : B. First slowly and then steeply

49. Dynamic viscosity of most of the gases with rise in temperature

Correct : A. Increases

50. According to Bernoulli's equation

Correct : A. Z + p/w + v²/2g = constant

51. For a body floating in a liquid the normal pressure exerted by the liquid acts at

Correct : D. All points on the surface of the body

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

Correct : B. Shear stress and rate of shear strain

53. A fluid in equilibrium can't sustain

Correct : C. Shear stress

54. Liquids

Correct : D. None of the above

55. When a cylindrical vessel containing liquid is resolved, the surface of the liquid takes the shape of

Correct : B. A paraboloid

56. Fluid is a substance that

Correct : D. Cannot remain at rest under action of any shear force

57. The property of a fluid which enables it to resist tensile stress is known as

Correct : C. Cohesion

58. The surface tension of mercury at normal temperature compared to that of water is

Correct : A. More

59. The unit of viscosity is

Correct : B. kg-sec/meter

60. Choose the wrong statement. Alcohol is used in manometer, because

Correct : A. Its vapour pressure is low

61. A fluid which obeys the Newton's law of viscosity is termed as

Correct : C. Newtonian fluid

62. In order that flow takes place between two points in a pipeline, the differential pressure between these points must be more than

Correct : D. All of the above

63. The value of coefficient of velocity for a sharp edged orifice __________ with the head of water.

Correct : B. Increases

64. If cohesion between molecules of a fluid is greater than adhesion between fluid and glass, then the free level of fluid in a dipped glass tube will be

Correct : C. Lower than the surface of liquid

65. A one dimensional flow is one which

Correct : D. Involves zero transverse component of flow

66. According to Manning's formula, the discharge through an open channel is (where M = Manning's constant)

Correct : B. A × M × m2/3 × i1/2

67. The property of fluid by virtue of which it offers resistance to shear is called

Correct : D. Viscosity

68. Coefficient of velocity is defined as the ratio of

Correct : A. Actual velocity of jet at vena contracta to the theoretical velocity

69. A liquid compressed in cylinder has a volume of 0.04 m3 at 50 kg/cm² and a volume of 0.039 m3 at 150 kg/cm². The bulk modulus of elasticity of liquid is

Correct : B. 4000 kg/cm²

70. The mass of 2.5 m3 of a certain liquid is 2 tonnes. Its mass density is

Correct : D. 800 kg/m3

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

Correct : A. Surface tension

72. When the Mach number is less than unity, the flow is called

Correct : A. Sub-sonic flow

73. The product of mass and acceleration of flowing liquid is called

Correct : A. Inertia force

74. Ratio of inertia force to elastic force is known as

Correct : A. Mach number

75. Euler's number is the ratio of __________ force to pressure force.

Correct : A. Inertia

76. Ratio of inertia force to surface tension is known as

Correct : D. Weber's number

77. The force present in a moving liquid is

Correct : D. All of these

78. A ship whose hull length is 100 m is to travel at 10 m/sec. For dynamic similarity, at what velocity should a 1:25 model be towed through water?

Correct : C. 2 m/sec

79. When the Mach number is more than 6, the flow is called

Correct : D. Hyper-sonic flow

80. The ratio of the inertia force to the viscous force is called

Correct : A. Reynold's number

81. Reynold's number is the ratio of the inertia force to the

Correct : B. Viscous force

82. 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

83. Reynold's number is the ratio of inertia force to

Correct : D. Viscous force

84. Principle of similitude forms the basis of

Correct : B. Designing models so that the result can be converted to prototypes

85. Select the correct statement

Correct : D. Weber's number is the ratio of inertia force to surface tension force

86. For similarity, in addition to models being geometrically similar to prototype, the following in both cases should also be equal

Correct : D. All the four ratios of inertial force to force due to viscosity, gravitation, surface tension, and elasticity

87. The ratio of the inertia force to the __________ is called Euler's number.

Correct : A. Pressure force

88. Dimensions of surface tension are

Correct : A. ML°T⁻²

89. Centrifugal pump is a

Correct : A. Turbomachinery

90. Turbomachines work under

Correct : B. Newtons second law

91. The main function of centrifugal pumps are to

Correct : D. Transfer energy

92. Turbines and compressors work with the gas, while centrifugal pump transfers energy.

Correct : A. True

93. The inlet passage of water entry is controlled by

Correct : B. Gate

94. Centrifugal pumps are used to transport

Correct : D. Fluid View Answer

95. Centrifugal pumps transport fluids by converting

Correct : A. Kinetic energy to hydrodynamic energy

96. With the increase in load, Energy in the turbine

Correct : A. Decreases

97. When the balancing of the turbine is disturbed, we use

Correct : D. Emergency governing View Answer

98. The fluid coming into the centrifugal pump is accelerated by

Correct : B. Impeller

99. A gear pump uses

Correct : B. Meshing of gears

100. The fundamental significance of all the turbomachinery is

Correct : A. Conservation of momentum