Quiznetik

Fluid Mechanics and Hydraulic Machines | Set 1

1. The branch of Engineering-science, which deals with water at rest or in motion is called

Correct : A. hydraulics

2. A solid can resist which of the following stresses?

Correct : D. All of the above.

3. .......... possesses no definite volume and is compressible.

Correct : C. Gas

4. The ratio of the specific weight of the liquid to the specific weight of a standard fluid is known as

Correct : C. Specific gravity

5. The property of a fluid which determines its resistance to shearing stress is called

Correct : A. Viscosity

6. Fluids which do not follow the linear relationship between shear stress and rate of deformation are termed as.... fluids.

Correct : B. Non-Newtonian

7. The printer’s ink is an example of

Correct : C. Thixotropic substance

8. The viscosity of liquids ..... with increase in temperature.

Correct : A. Decreases

9. Surface tension is caused by the force of ..... at the free surface.

Correct : A. Cohesion

10. Which of the following is an example of phenomenon of surface tension?

Correct : D. All of the above.

11. Surface tension is expressed in

Correct : A. N/m

12. Pressure inside a water droplet is given by the relation

Correct : A. p = 4𝜎/d

13. . ...... is a phenomenon by which a liquid rises into a thin glass tube above or below its general level.

Correct : B. Capillarity

14. The capillary rise of water in the glass tube is given by

Correct : C. h = 4σ/wd

15. Elasticity of fluids is measured in terms of

Correct : C. Bulk modulus of elasticity

16. Compressibility is the reciprocal of

Correct : A. Bulk modulus of elasticity

17. Bulk modulus of elasticity is the ratio of

Correct : C. Compressive stress to volumetric strain

18. The value of bulk modulus of elasticity .......... with increase of pressure.

Correct : A. Increases

19. The pressure of a liquid on a surface will always act ...... to the surface.

Correct : B. Normal

20. The pressure ....... as the depth of the liquid increases.

Correct : A. Increases

21. The intensity of pressure in a liquid due to its depth will vary .... with depth.

Correct : A. Directly

22. The height of the free surface above any point is known as

Correct : A. Static head

23. “The intensity of pressure at any point in a liquid at rest is the same in all directions.” The above statement is known as

Correct : B. Pascal’s law

24. Any pressure measured above the absolute zero of pressure is termed as

Correct : C. Either of the above

25. The fundamental S.I. unit of pressure is N/m2; this is also known as ......

Correct : A. Pascal

26. The intensity of pressure p is related to specific weight w of the liquid and vertical depth h of the point by the equation

Correct : A. p = wh

27. The point of application of the total pressure on the surface is

Correct : B. Centre of pressure

28. If A is the area of the immersed surface, w is the specific weight of the liquid and ͞x is the depth of horizontal surface from the liquid surface, then the total pressure P on the surface is given by

Correct : C. p = wA ͞x

29. The side of the dam to which the water from the river or the stream approaches is known as

Correct : B. Upstream

30. Lock gates are provided to

Correct : A. Change the water level in a canal or river for irrigation

31. The term........ means the study of pressure exerted by a fluid at rest.

Correct : A. Hydrostatics

32. The tendency for an immersed body to be lifted up in the fluid, due to an upward force opposite to the action of gravity is known as

Correct : A. Buoyancy

33. The magnitude of the buoyant force can be determined by

Correct : B. Archimedes’ principle

34. When a body is immersed in a fluid, partially or completely, the force of buoyancy is equal to

Correct : B. The weight of the fluid displaced by the body

35. The point of application of the force of buoyancy on the body is known as

Correct : B. Centre of buoyancy

36. “When a body is immersed in a fluid either wholly or partially, it is buoyed or lifted up by a force which is equal to the weight of fluid displaced by the body”. This principle was enunciated by

Correct : A. Archimedes

37. A floating body is in stable equilibrium when

Correct : B. The metacentre is above its centre of gravity

38. An ice-cube is floating in glass of water. As the cube melts the water level

Correct : B. Falls

39. Metacentric height can be determined by

Correct : C. Both (a) and (b)

40. If a body does not return to its original position from the slightly displaced angular position and heels farther away, when given a small angular displacement; such an equilibrium is called

Correct : B. Unstable equilibrium

41. The motion of fluid particles may be described by which of the following methods?

Correct : C. Both (a) and (b)

42. In which of the following methods, the observer concentrates on a point in the fluid system?

Correct : D. None of the above.

43. Normal acceleration in fluid-flow situation exists only when

Correct : B. The flow is two-dimensional

44. In a steady flow the velocity

Correct : B. At a given point does not change with time

45. The flow in a pipe whose valve is being opened or closed gradually is an example of

Correct : B. Unsteady flow

46. The type of flow in which the velocity at any given time does not change with respect to space is called

Correct : C. Uniform flow

47. Flow in a pipe where average flow parameters are considered for analysis is an example of

Correct : B. One-dimensional flow

48. The flow in a river during the period of heavy rainfall is

Correct : D. Unsteady, non-uniform and three-dimensional.

49. Flow between parallel plates of infinite extent is an example of

Correct : B. Two-dimensional flow

50. If the flow is irrational as well as steady it is known as

Correct : C. Potential flow

51. High velocity flow in a conduit of large size is known as

Correct : B. Turbulent flow

52. If the Reynolds number is less than 2000, the flow in a pipe is

Correct : A. Laminar flow

53. The path followed by fluid particle in motion is called a

Correct : B. Path line

54. A....is an imaginary line within the flow so that the tangent at any point on it indicates the velocity at that point.

Correct : B. Stream line

55. A stream line is one

Correct : B. In which the flow cannot cross the bounding surface

56. ...... is a curve which gives an instantaneous picture of the location of the fluid particles which have passed through a given point.

Correct : C. Streak line

57. In fluid mechanics, the continuity equation is a mathematical statement embodying the principle of

Correct : B. Conservation of mass

58. An irrational flow is one in which

Correct : C. The net rotation of fluid particles about their mass centres remains zero

59. In a fluid-flow the stream lines are lines

Correct : B. Along which the stream function ψ = constant

60. ....... is defined mathematically as the line integral of the tangential velocity about a closed path (contour).

Correct : A. Circulation

61. The concept of stream function which is based on the principle of continuity is applicable to

Correct : B. Two-dimensional flow only

62. The motion is described as ......when the components of rotation or vorticity are zero throughout certain point of the fluid.

Correct : B. Irrotational

63. ........ is defined as a scalar function of space and time such that its negative derivative with respect to any direction gives the fluid velocity in that direction.

Correct : A. Velocity potential function

64. If velocity potential (φ) satisfies the Laplace equation, it represents the possible..... flow.

Correct : D. Steady, incompressible, irrotational.

65. A flow net is a graphical representation of strea lines and equipotential lines such that these lines

Correct : A. Intersect each other orthogonally forming curvilinear squares

66. Velocity head is given by

Correct : B. V2/2g

67. Euler’s equation (in differential form) is written as:

Correct : B. dp/ρ + v.dv + g.dz = 0

68. In which of the following measuring devices Bernoulli’s equation is used:

Correct : D. All the above.

69. The co-efficient of discharge of an orificemeter is ......that of a venturimeter.

Correct : B. Much smaller than

70. The piezometric head is the summation of :

Correct : B. Pressure head and elevation head

71. The total-energy-line in pipe flow is a graphical representation of the Bernoulli’s equation and represents the sum of velocity head, pressure head and the elevation head above:

Correct : B. The arbitrary horizontal datum

72. The total energy represented by the Bernoulli’s equation (p/ρg +V2/2g +z) has the units:

Correct : D. Nm/N.

73. The Bernoulli’s equation written in the conventional form p/ρg + V2/2g + z = constant total energy per unit of certain quantity. Identify this quantity from the choices given below:

Correct : B. Energy per unit weight

74. A venturimeter is used for measuring:

Correct : B. Flow rate

75. The co-efficient of discharge (Cd) of venturimeter lies within the limits:

Correct : A. 0.95 to 0.99

76. A Pitot-tube is used for measuring:

Correct : A. Velocity of flow

77. When a Pitot-tube is put to use it must be ensured that its alignment is such that:

Correct : C. Its opening faces upstream and the horizontal leg is perfectly aligned with the direction of flow

78. The hydraulic gradient-line indicates the variation of which of the following:

Correct : B. Piezometric head in the direction of flow

79. The momentum correction factor β is used to account for:

Correct : C. Non-uniform distribution of velocities at inlet and outlet sections

80. The change in moment of momentum of fluid due to flow along a curved path results in:

Correct : B. Torque

81. Which of the following is an example of free vortex flow?

Correct : D. All of the above.

82. In case of forced vortex, the rise of liquid level at the ends is .... the fall of liquid level at the axis of rotation.

Correct : C. Equal to

83. In case of a closed cylindrical vessel sealed at the top and the bottom the volume of air before rotation is ...... the volume of air after:

Correct : C. Equal to

84. Dimensional analysis is used to

Correct : D. All of the above.

85. Which of the following is an advantage of dimensional analysis?

Correct : D. All of the above.

86. dimensionally homogeneous equation is applicable to

Correct : D. All systems of units.

87. In which of the following methods of dimensional analysis, a functional relationship of some variables is expressed in the form of an exponential equation, which must be dimensionally homogeneous?

Correct : B. Rayleigh’s method

88. In dimensional analysis the Buckingham’s π–theorem is widely used and expresses the resulting equation in terms of

Correct : C. (n – m) dimensionless parameters

89. To apply Buckingham’s π–theorem, m repeating variables are selected from amongst the n variables influencing the phenomenon. The repeating variables are selected such that they

Correct : C. In combination contain each of the m fundamental dimensions involved in the problem.

90. In order that results obtained in model studies correctly represent the behaviour of the prototype, which of the following similarities must be ensured between the model and the prototype?

Correct : D. All of the above.

91. Dynamic similarity between the model and prototype is the

Correct : C. Similarity of forces

92. ...... is equal to the product of shear stress due to viscosity and surface area of flow.

Correct : A. Viscous force

93. Kinematic similarity between model and prototype is the

Correct : C. Similarity of streamline pattern

94. ......... is the ratio of the inertia force to the viscous force.

Correct : C. Reynolds number

95. ........ is the square root of the ratio of the inertia force to the pressure force.

Correct : C. Euler’s number

96. Euler number is important in which of the following flow situations?

Correct : D. All of the above

97. Mach’s number is defined as the square root of the ratio of the

Correct : C. Inertia force to the elastic force

98. ...... is important in compressible fluid flow problems at high velocities, such as high velocity flow in pipes or motion of high-speed projectiles and missiles.

Correct : B. Mach’s number

99. Distorted models are required to be prepared for which of the following?

Correct : D. All of the above.

100. The scale effect in models can be

Correct : C. Both positive and negative