Quiznetik

Hydraulics and Fluid Mechanics | Set 5

1. A flow in which the volume of a fluid and its density does no change during the flow is called

Correct : A. incompressible

2. The volume of a fluid

Correct : B. decreases

3. The most economical section of a rectangular channel is one which has hydraulic mean depth or hydraulic radius equal to

Correct : A. half the depth

4. The value of coefficient of discharge is

Correct : A. less than

5. A flow in which the viscosity of fluid is dominating over the inertia force is called

Correct : C. laminar flow

6. Whenever a plate is held immersed at some angle with the direction of flow of the liquid, it is subjected to some pressure. The component of this pressure, at right angles to the direction of flow of the liquid is known as lift.

Correct : A. True

7. A notch is, usually, made of a metallic plate.

Correct : A. Correct

8. The flow of water through the hole in the bottom of a wash basin is an example of

Correct : C. free vortex

9. When a body is immersed wholly or partially in a liquid, it is lifted up by a force equal to the weight of liquid displaced by the body. This statement is called

Correct : B. Archimede's principle

10. The difference between the notch and weir is that the notch is of bigger size and the weir is of a smaller size.

Correct : B. Disagree

11. The hydraulic gradient line lies over the centre line of the pipe by an amount equal to the

Correct : A. pressure head

12. When the pressure intensity at a point is more than the local atmospheric pressure, then the difference of these two pressures is called

Correct : C. positive gauge pressure

13. The length of the divergent cone in a venturimeter is

Correct : C. three to four times

14. The depth of water in a channel corresponding to the minimum specific energy is known as critical depth.

Correct : A. Agree

15. The total energy line lies over the centre line of the pipe by an amount equal to

Correct : C. pressure head + velocity head

16. The metacentric height of a ship is 0.6 m and the radius of gyration is 4 m. The time of rolling of a ship is

Correct : C. 10.4s

17. The pressure at a stagnation point is always low.

Correct : B. Disagree

18. In an internal mouthpiece, the absolute pressure head at vena contracta is

Correct : A. less than

19. The hydraulic mean depth for a circular pipe of diameter (d) is

Correct : B. d / 4

20. According to Newton's law of viscosity, the shear stress on a layer of a fluid is

Correct : B. directly proportional

21. A moving fluid mass may be brought to a static equilibrium position, by aplying an imaginary inertia force of the same magnitude as that of the accelerating force but in the opposite direction. This statement is called

Correct : C. D-Alembert's principle

22. The siphon is used to connect two reservoirs at different levels intervened by a high ridge.

Correct : A. True

23. The discharge through a channel of circular section will be maximum when the depth of water is

Correct : D. 0.95 times

24. If the value of coefficient of discharge increases, the discharge through the orifice decreases.

Correct : B. False

25. The Francis formula for the discharge over Cippoletti weir is

Correct : C. 1.84 LH3/2

26. A differential manometer is used to measure

Correct : D. difference of pressures between two points in pipe

27. When a cylindrical vessel containing liquid is revolved about its vertical axis at a constant angular velocity, the pressure

Correct : A. varies as the square of the radial distance

28. The point at which the resultant pressure on an immersed surface acts, is known as

Correct : C. centre of pressure

29. The Reynold's number of a ship is

Correct : A. directly proportional

30. The purpose of a surge tank is

Correct : D. all of the above

31. 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

32. Which of the following statement is wrong?

Correct : C. The length of divergent portion in a venturimeter is equal to the convergent portion.

33. The length of a liquid stream while flowing over a weir

Correct : C. contracts

34. If a body floating in a liqid 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

Correct : A. neutral

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

Correct : D. 800 kg / m3

36. A pitot tube is used to measure the

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

37. In an internal mouthpiece, if the jet after contraction expands and fills up the whole mouthpiece, then the mouthpiece is said to be running free.

Correct : B. False

38. The water hammer in pipes occurs due to sudden change in the velocity of flowing liquid.

Correct : A. Agree

39. 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

40. The viscosity of water is

Correct : A. higher

41. The siphon will work satisfactorily, if the minimum pressure in the pipe is

Correct : C. more than

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

Correct : A. sub-sonic flow

43. Froude's number is the ratio of inertia force to

Correct : C. gravity force

44. In flow in which each liquid particle does not have a definite path and the paths of individual particles also cross each other, is called turbulent flow.

Correct : A. Agree

45. The coefficient of discharge in case of internal mouthpiece is

Correct : A. less than

46. The hydraulic gradient line is always parallel to the centre line of the pipe.

Correct : B. Incorrect

47. In two dimensional flow, the flow does not take place in a curve.

Correct : B. False

48. A closed tank is completely filled with an oil. If it is made to move with a horizontal acceleration, then the pressure at the back end will be more than that at the front end.

Correct : A. Correct

49. Which of the following statement is correct ?

Correct : D. all of the above

50. The metacentric height is the distance between the

Correct : B. centre of gravity of the floating body and the metacentre

51. A structure whose width is

Correct : A. less than

52. One poise is equal to

Correct : A. 0.1 N-s/m2

53. According to equation of continuity,

Correct : C. a1v1 = a2v2

54. An air vessel is provided at the summit in a syphon to

Correct : A. avoid interruption in the flow

55. In a venturiflume, the flow takes place at

Correct : A. atmospheric pressure

56. The discharge over a triangular notch is

Correct : D. directly proportional to H5/2

57. Kinematic viscosity is the product of dynamic viscosity and the density of the liquid.

Correct : B. No

58. The total energy of a liquid particle in motion is equal to

Correct : A. pressure energy + kinetic energy + potential energy

59. The velocity of flow is same at all points in the cross-section of a channel.

Correct : B. False

60. A notch is used to measure

Correct : B. Disagree

61. The most efficient section of a channel is

Correct : D. trapezoidal

62. An orifice is said to be large, if

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

63. A weir is said to be narrow-crested weir, if the width of the crest of the weir is

Correct : B. less than

64. The rise, in water level, which occurs during the transformation of the unstable shooting flow to the stable streaming flow is called hydraulic jump.

Correct : A. Yes

65. Water is a

Correct : C. newtonian

66. A pipe of length more than double the diameter of orifice fitted externally or internally to the orifice is called a

Correct : C. mouthpiece

67. The body will sink down if the force of buoyancy is

Correct : B. less than

68. In a short cylindrical external mouthpiece, the vena contracta occurs at a distance

Correct : B. one-fourth

69. The viscosity of water at 20? C is

Correct : D. one centipoise

70. A thick liquid like a syrup has a

Correct : B. greater

71. Laminar flow

Correct : A. takes

72. The surface tension of mercury at normal temperature is

Correct : C. higher than

73. An error of 1% in measuring head over the apex of the notch (H) will produce an error of

Correct : D. 2.50%

74. The pressure measured with the help of a piezometer tube is in

Correct : C. head of liquid

75. Bulk modulus of a fluid

Correct : C. increases

76. Gauge pressure at a point is equal to the absolute pressure

Correct : B. minus

77. 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

Correct : C. 2H / 3

78. A weir, generally, used as a spillway of a dam is

Correct : C. Ogee weir

79. The ratio of the inertia force to the

Correct : A. pressure force

80. One litre of water occupies a volume of

Correct : D. 1000 cm3

81. The density of air is same at different heights.

Correct : B. Incorrect

82. The maximum discharge over a broad crested weir is

Correct : D. 1.71 Cd x L x H3/2

83. The centre of pressure acts

Correct : C. below

84. The coefficient of discharge is the ratio of theoretical discharge to the actual discharge through an orifice.

Correct : B. False

85. When a vertical wall is subjected to pressures due to liquid on both sides, the resultant pressure is the

Correct : B. difference

86. In the manufacturing of lead shots, the property of surface tension is utilised.

Correct : A. Agree

87. If a body floating in a liquid does not return back to its original position, and heels farther away when given a small angular displacement, the body is said to be in neutral equilibrium.

Correct : B. No

88. The total pressure on the bottom of a closed cylindrical vessel completely filled up with a liquid is the sum of the total centrifugal pressure and the weight of the liquid in the vessel

Correct : A. Correct

89. A body floating in a liquid is said to be in a stable equilibrium, if its metacentre coincides with its centre of gravity.

Correct : A. Agree

90. The body will float if the force of buoyancy is

Correct : C. more than

91. All the gases are considered to have compressible flow and all the liquids are considered to have incompressible flow.

Correct : A. Correct

92. When the venturimeter is inclined, then for a given flow it will show

Correct : A. same

93. With an increase in size of tube, the rise or depression of liquid in the tube due to surface tension will

Correct : A. decrease

94. When the Mach number is equal to unity, the flow is called sonic flow.

Correct : A. True

95. A submerged body is said to be in a stable equilibrium, if its centre of gravity

Correct : B. lies below

96. If a pitot tube is placed with its nose upstream, downstream or sideways, the reading will be the same in every case.

Correct : B. False

97. The weight per unit volume of a liquid at a standard temperature and pressure is called

Correct : A. specific weight

98. The volume per unit mass of a liquid is called specific volume.

Correct : A. Yes

99. The flow at critical depth in an open channel is called torrential flow.

Correct : B. No

100. The reciprocal of Euler's number is called Newton number.

Correct : A. Yes