Mechanical Engineering : Hydraulics and Fluid Mechanics MCQs with Answers

1 .
What is fluid mechanics?
A)  Study of fluid behaviour in motion
B)  Study of fluid behaviour at rest
C)  Study of fluid behaviour at rest and in motion
D)  Study of fluid behaviour at rest and in motion

Correct Answer :   Study of fluid behaviour at rest and in motion

Explanation : The study of fluid behaviour (liquids, gases, blood, and plasmas) at rest and in motion is known as fluid mechanics. Fluid mechanics has numerous applications in mechanical and chemical engineering, as well as biological and astrophysical systems.

2 .
A hydraulic ram is a device used to
A)  Store the energy of water
B)  To lift water from deep wells
C)  Increase the pressure of water
D)  To lift small quantity of water to a greater height when a large quantity of water is available at a smaller height

Correct Answer :   To lift small quantity of water to a greater height when a large quantity of water is available at a smaller height

3 .
The specific gravity of water is taken as
A)  1
B)  0.1
C)  0.01
D)  0.001

Correct Answer :   1

4 .
A pitot tube is used to measure the
A)  discharge through a pipe
B)  velocity of flow at the required point in a pipe
C)  total pressure of liquid flowing in a pipe
D)  pressure difference between two points in a pipe

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

5 .
The weight per unit volume of a liquid at a standard temperature and pressure is called
A)  specific weight
B)  mass density
C)  specific gravity
D)  None of the above

Correct Answer :   specific weight

6 .
The centre of buoyancy is the centre of area of the immersed body.
A)  Correct
B)  Incorrect
C)  Can not Say
D)  --

Correct Answer :   Correct

7 .
The pressure of air __________ with the increase of height from the surface of the earth.
A)  increases
B)  decreases
C)  does not change
D)  None of the above

Correct Answer :   decreases

8 .
The sheet of water flowing over a notch or a weir is known as
A)  orifice
B)  sill or crest
C)  nappe or vein
D)  None of the above

Correct Answer :   nappe or vein

9 .
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.
A)  Yes
A)  
B)  No
B)  
C)  Can not Say
C)  
D)  None of the above
D)  

Correct Answer :  

10 .
The length of the divergent cone in a venturimeter is __________ that of the convergent cone.
A)  double
B)  equal to
C)  three to four times
D)  five to six times

Correct Answer :   three to four times

11 .
Bulk modulus of a fluid is the ratio of
A)  shear stress to shear strain
B)  critical velocity to the viscosity of fluid
C)  increase in volume to the viscosity of fluid
D)  increase in pressure to the volumetric strain

Correct Answer :   increase in pressure to the volumetric strain

12 .
The pressure at a point 4 m below the free surface of water is
A)  19.24 kPa
B)  29.24 kPa
C)  39.24 kPa
D)  49.24 kPa

Correct Answer :   39.24 kPa

13 .
A structure used to dam up a stream or river over which the water flows is called
A)  dam
B)  notch
C)  orifice
D)  weir

Correct Answer :   weir

14 .
The hydraulic mean depth or the hydraulic radius is the ratio of
A)  area of flow and wetted perimeter
B)  velocity of flow and area of flow
C)  wetted perimeter and diameter of pipe
D)  None of the above

Correct Answer :   area of flow and wetted perimeter

15 .
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
A)  steak line
B)  stream line
C)  path line
D)  potential line

Correct Answer :   stream line

16 .
Stoke is the unit of
A)  dynamic viscosity in S. I. units
B)  dynamic viscosity in M. K. S. units
C)  kinematic viscosity in C. G. S. units
D)  kinematic viscosity in M. K. S. units

Correct Answer :   kinematic viscosity in C. G. S. units

17 .
In a short cylindrical external mouthpiece, the vena contracta occurs at a distance __________ the diameter of the orifice from the outlet of orifice.
A)  equal to
B)  one-half
C)  one-third
D)  one-fourth

Correct Answer :   one-fourth

18 .
Viscous force is the __________ of shear stress due to viscosity and cross-sectionar area of flow.
A)  product
B)  sum
C)  ratio
D)  different

Correct Answer :   product

19 .
An internal mouthpiece is said to be running free if the length of the mouthpiece is __________ the diameter of the orifice.
A)  less than twice
B)  more than twice
C)  less than three times
D)  more than three times

Correct Answer :   less than three times

20 .
The discharge over a rectangular notch is
A)  inversely proportional to H3/2
A)  
B)  directly proportional to H3/2
B)  
C)  directly proportional to H5/2
C)  
D)  inversely proportional to H5/2
D)  

Correct Answer :   directly proportional to H3/2

21 .
A flow in which the quantity of liquid flowing per second is constant, is called __________ flow.
A)  Turbulent
B)  Unsteady
C)  Steady
D)  Streamline

Correct Answer :   Steady

22 .
The Cipoletti weir is a __________ weir.
A)  Circular
B)  Triangular
C)  Rectangular
D)  Trapezoidal

Correct Answer :   Trapezoidal

23 .
The tangential velocity of the water element having a free vortex is
A)  Directly proportional to its distance from the centre
B)  Inversely proportional to its distance from the centre
C)  Directly proportional to its (distance)2 from the centre
D)  Inversely proportional to its (distance)2 from the centre

Correct Answer :   Inversely proportional to its distance from the centre

24 .
Which of the following is the basic principle of fluid mechanics?
A)  Energy equation
B)  Momentum principle
C)  Continuity equation
D)  All of the above

Correct Answer :   All of the above

Explanation : The continuity equation (i.e. mass conservation), the momentum principle (or momentum conservation), and the energy equation are the three basic fluid mechanics principles.

25 .
What is fluid mechanics used for?
A)  Fluid mechanics enables to comprehend the behaviour of solid fluids under pressure
B)  Fluid mechanics enables to comprehend the behaviour of fluids under various temperatures only
C)  Fluid mechanics enables to comprehend the behaviour of fluids under a variety of forces & atmospheric conditions
D)  None of the above

Correct Answer :   Fluid mechanics enables to comprehend the behaviour of fluids under various temperatures only

26 .
If a person studies about a fluid which is at rest, what will you call his domain of study?
A)  Fluid Statics
B)  Fluid Dynamics
C)  Fluid Mechanics
D)  Fluid Kinematics

Correct Answer :   Fluid Statics

Explanation : Fluid Mechanics deals with the study of fluid at rest or in motion with or without the consideration of forces, Fluid Statics is the study of fluid at rest, Fluid Kinematics is the study of fluid in motion without consideration of forces and Fluid Dynamics is the study of fluid in motion considering the application forces.

27 .
The total head of a liquid particle in motion is equal to
A)  kinetic head - (pressure head + potential head)
B)  pressure head - (kinetic head + potential head)
C)  pressure head + kinetic head + potential head
D)  potential head - (pressure head + kinetic head)

Correct Answer :   pressure head + kinetic head + potential head

28 .
An internal mouthpiece is said to be running _____ if the length of the mouthpiece is more than three times the diameter of the orifice.
A)  free
B)  full
C)  partially
D)  None of the above

Correct Answer :   full

29 .
The metacentric heights of two floating bodies A and B are 1 m and 1.5 m respectively. Select the correct statement.
A)  The bodies A and B are unstable
B)  The bodies A and B have equal stability
C)  The body A is more stable than body B
D)  The body B is more stable than body A

Correct Answer :   The body B is more stable than body A

30 .
In open channels, the specific energy is the
A)  total energy per unit discharge
B)  total energy measured above the horizontal datum
C)  kinetic energy plotted above the free surface of water
D)  total energy measured with respect to the datum passing through the bottom of the channel

Correct Answer :   total energy measured with respect to the datum passing through the bottom of the channel

31 .
The Bernoulli's equation is based on the assumption that
A)  there is no loss of energy of the liquid flowing
B)  no force except gravity acts on the fluid
C)  the velocity of flow is uniform across any cross-section of the pipe
D)  All of the above

Correct Answer :   All of the above

32 .
A flow in which the quantity of liquid flowing per second is not constant, is called
A)  unsteady flow
B)  steady flow
C)  turbulent flow
D)  streamline flow

Correct Answer :   unsteady flow

33 .
In a sharp-crested weir, the thickness of the weir is kept less than half of the height of water above the crest of the weir.
A)  True
B)  False
C)  Can not Say
D)  None of the above

Correct Answer :   True

34 .
A flow through a long pipe at constant rate is called
A)  unsteady uniform flow
B)  steady uniform flow
C)  steady non-uniform flow
D)  unsteady non-uniform flow

Correct Answer :   steady uniform flow

35 .
In an external or internal mouthpiece, the absolute pressure head at vena contracta is zero when atmospheric pressure head is 10.3 m of water.
A)  Correct
B)  Incorrect
C)  Can not Say
D)  None of the above

Correct Answer :   Correct

36 .
The coefficient of discharge for an external mouthpiece depends upon
A)  pressure of liquid
B)  velocity of liquid
C)  length of mouthpiece
D)  area of mouthpiece

Correct Answer :   length of mouthpiece

37 .
The highest efficiency is obtained with a channel of __________ section.
A)  square
B)  circular
C)  rectangular
D)  trapezoidal

Correct Answer :   trapezoidal

38 .
A vessel of 4 m³ contains an oil which weighs 30 kN. The specific weight of the oil is
A)  4.5 kN/m³
B)  6 kN/m³
C)  7.5 kN/m³
D)  10 kN/m³

Correct Answer :   7.5 kN/m³

39 .
Coefficient of discharge Cd is equal to (where Cc = Coefficient of contraction, Cv = Coefficient of velocity, and Cr = Coefficient of resistance)
A)  Cc x Cv
A)  
B)  Cc/Cr
B)  
C)  Cc x Cr
C)  
D)  Cv x Cr
D)  

Correct Answer :   Cc x Cv

40 .
In an internal mouthpiece, if the jet after contraction does not touch the sides of the mouthpiece, then the mouthpiece is said to be
A)  running full
B)  running free
C)  partially running full
D)  partially running free

Correct Answer :   running free

41 .
The value of coefficient of velocity for a sharp edged orifice __________ with the head of water.
A)  increases
B)  decreases
C)  Can not Say
D)  None of the above

Correct Answer :   increases

42 .
One poise is equal to
A)  1 N-s/m²
B)  0.1 N-s/m²
C)  10 N-s/m²
D)  100 N-s/m²

Correct Answer :   0.1 N-s/m²

43 .
The absolute pressure is equal to
A)  gauge pressure - vacuum pressure
B)  atmospheric pressure - gauge pressure
C)  gauge pressure - atmospheric pressure
D)  gauge pressure + atmospheric pressure

Correct Answer :   gauge pressure + atmospheric pressure

44 .
When the pressure intensity at a point is more than the local atmospheric pressure, then the difference of these two pressures is called
A)  gauge pressure
B)  vacuum pressure
C)  absolute pressure
D)  positive gauge pressure

Correct Answer :   positive gauge pressure

45 .
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)
A)  wx
A)  
B)  wAx
B)  
C)  w.A
C)  
D)  wA/x
D)  

Correct Answer :   wAx

46 .
With an increase in size of tube, the rise or depression of liquid in the tube due to surface tension will
A)  increase
B)  remain unchanged
C)  decrease
D)  depend upon the characteristics of liquid

Correct Answer :   decrease

47 .
The volume of a fluid __________ as the pressure increases.
A)  increases
B)  decreases
C)  remains same
D)  None of the above

Correct Answer :   decreases

48 .
The pressure of the liquid flowing through the divergent portion of a venturimeter
A)  decreases
B)  increases
C)  remains constant
D)  depends upon mass of liquid

Correct Answer :   decreases

49 .
The difference of pressure between the inside and outside of a liquid drop is
A)  p=T/r
B)  p=T×r
C)  p=T/2r
D)  p=2T/r

Correct Answer :   p=2T/r

50 .
A jet of water discharging from a 40 mm diameter orifice has a diameter of 32 mm at its vena contracta. The coefficient of contraction is
A)  0.46
B)  0.64
C)  0.78
D)  0.87

Correct Answer :   0.64

51 .
When a body, floating in a liquid, is given a small angular displacement, it starts oscillating about a point known as
A)  Centre of gravity
B)  Centre of pressure
C)  Metacentre
D)  Centre of buoyancy

Correct Answer :   Metacentre

52 .
Fluid is a substance that
A)  Always expands until it fills any container
B)  Cannot remain at rest under action of any shear force
C)  Cannot be subjected to shear forces
D)  Has the same shear stress at a point regardless of its motion

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

53 .
If the ratios of all the corresponding linear dimensions are equal, then the model and the prototype are said to have
A)  Geometric similarity
B)  Dynamic similarity
C)  Kinematic similarity
D)  None of the above

Correct Answer :   Geometric similarity

54 .
Which of the following method is used exclusively in fluid mechanics?
A)  Eulerian method
B)  Lagrangian method
C)  Both Lagrangian and Eulerian methods
D)  Neither Lagrangian nor Eulerian method

Correct Answer :   Eulerian method

Explanation : In Fluid Mechanics, the matter of concern is the general state of motion at various points in the fluid system (as in Eulerian approach) rather than the motion of each particle (as in Lagrangian approach). Hence, the Eulerian method is extensively used in Fluid Mechanics.

55 .
Which of the following method is most commonly used in fluid mechanics for analysis?
A)  Langragian method
B)  Control volume analysis
C)  Eulerian Method
D)  None of the above

Correct Answer :   Eulerian Method

Explanation : In Eulerian method,we describe velocity, acceleration pressure etc at a point in flow field.hence, it is also most commonly used in fluid mechanics.

56 .
When is a fluid called turbulent?
A)  High viscosity of fluid
B)  The density of the fluid is low
C)  Reynolds number is greater than 2000
D)  Reynolds number is less than 2000

Correct Answer :   Reynolds number is less than 2000

Explanation : Reynolds number is a dimensionless quantity. It helps to predict the flow pattern in fluid mechanics. At high Reynolds number, the flow has a very high density, due to which the value of Reynolds number is greater than 2000.

57 .
The coefficient of viscosity may be determined by
A)  Capillary tube method
B)  Orifice type viscometer
C)  Rotating cylinder method
D)  All of the above

Correct Answer :   All of the above

58 .
A vertical wall is subjected to a pressure due to one kind of liquid, on one of its sides. Which of the following statement is correct?
A)  The pressure on the bottom of the wall is maximum.
B)  The pressure on the wall at the liquid level is zero, and on the bottom of the wall is maximum
C)  The pressure on the bottom of the wall is zero.
D)  The pressure on the wall at the liquid level is minimum.

Correct Answer :   The pressure on the wall at the liquid level is zero, and on the bottom of the wall is maximum

59 .
Water is a ______ fluid.
A)  newtonian
B)  real
C)  ideal
D)  non-newtonian

Correct Answer :   newtonian

60 .
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.
A)  True
B)  False
C)  Can not Say
D)  None of the above

Correct Answer :   False

61 .
A channel is said to be of most economical cross-section, if
A)  it has minimum wetted perimeter
B)  it involves lesser excavation for the designed amount of discharge
C)  it gives maximum discharge for a given cross-sectional area and bed slope
D)  All of the above

Correct Answer :   All of the above

62 .
The top of the weir over which the water flows is known as
A)  orifice
B)  nappe or vein
C)  sill or crest
D)  None of the above

Correct Answer :   sill or crest

63 .
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
A)  Pascal's law
A)  
B)  Archimede's principle
B)  
C)  D-Alembert's principle
C)  
D)  None of the above
D)  

Correct Answer :   D-Alembert's principle

64 .
A pipe of length more than double the diameter of orifice fitted externally or internally to the orifice is called a
A)  weir
B)  notch
C)  mouthpiece
D)  nozzle

Correct Answer :   mouthpiece

65 .
Which among the following is the standard symbol for Blake number?
A)  ba
B)  b
C)  Bi
D)  Bl

Correct Answer :   ba

Explanation : The standard symbol for Blake number is B or Bl. Blake number in fluid mechanics deals with geology, fluid mechanics and porous media. It is due to the inertial over the viscous forces in fluid flow through porous media.

66 .
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.
A)  H/2
B)  2H/3
C)  H/3
D)  3H/4

Correct Answer :   2H/3

67 .
A nozzle is generally made of
A)  divergent shape
B)  cylindrical shape
C)  convergent-divergent shape
D)  convergent shape

Correct Answer :   convergent shape

68 .
The unit of surface tension is
A)  N-m
B)  N/m
C)  N/m²
D)  N/m³

Correct Answer :   N/m

69 .
The body will sink down if the force of buoyancy is __________ the weight of the liquid displaced.
A)  less than
B)  equal to
C)  more than
D)  None of the above

Correct Answer :   less than

70 .
If a body floating in a liquid returns back to its original position, when given a small angular displacement, the body is said to be in
A)  neutral equilibrium
B)  unstable equilibrium
C)  stable equilibrium
D)  None of the above

Correct Answer :   stable equilibrium

71 .
The pressure measured with the help of a piezometer tube is in
A)  N/m²
B)  N/mm²
C)  head of liquid
D)  All of the above

Correct Answer :   head of liquid

72 .
In an external mouthpiece, the absolute pressure head at vena contracta is __________ the atmospheric pressure head by an amount equal to 0.89 times the height of the liquid, above the vena contracta.
A)  less than
A)  
B)  more than
B)  
C)  Can not Say
C)  
D)  None of the above
D)  

Correct Answer :   less than

73 .
The power transmitted through a pipe is (where w = Specific weight in N/m³, and Q = Discharge in m³/s)
A)  w x Q x H
A)  
B)  w x Q x hf
B)  
C)  w x Q (H - hf)
C)  
D)  w x Q (H + hf)
D)  

Correct Answer :   w x Q (H - hf)

74 .
When a cylindrical vessel containing liquid is revolved about its vertical axis at a constant angular velocity, the pressure
A)  increases linearly as its radial distance
B)  increases as the square of the radial distance
C)  decreases as the square of the radial distance
D)  varies as the square of the radial distance

Correct Answer :   varies as the square of the radial distance

75 .
The property of a liquid which offers resistance to the movement of one layer of liquid over another adjacent layer of liquid, is called
A)  capillarity
B)  viscosity
C)  surface tension
D)  compressibility

Correct Answer :   viscosity

76 .
Newton's law of viscosity is a relationship between
A)  shear stress and rate of shear strain
B)  shear stress and velocity
C)  pressure, velocity and temperature
D)  rate of shear strain and temperature

Correct Answer :   shear stress and rate of shear strain

77 .
The mercury does not wet the glass. This is due to the property of the liquid known as
A)  cohesion
B)  adhesion
C)  viscosity
D)  surface tension

Correct Answer :   surface tension

78 .
The coefficient of discharge in case of internal mouthpiece is __________ that of external mouthpiece.
A)  less than
B)  more than
C)  Can not Say
D)  None of the above

Correct Answer :   less than

79 .
According to Manning's formula, the discharge through an open channel is (where M = Manning's constant)
A)  A1/2 x M2/3 x m x i
A)  
B)  A x M x m1/2 x i2/3
B)  
C)  A x M x m2/3 x i1/2
C)  
D)  A2/3 x M1/3 x m x i
D)  

Correct Answer :   A x M x m2/3 x i1/2

80 .
When the venturimeter is inclined, then for a given flow it will show __________ reading.
A)  less
B)  same
C)  more
D)  None of the above

Correct Answer :   same

81 .
The shear stress-strain graph for a newtonian fluid is a
A)  elliptical
B)  parabolic curve
C)  straight line
D)  hyperbolic curve

Correct Answer :   straight line

82 .
If a pitot tube is placed with its nose upstream, downstream or sideways, the reading will be the same in every case.
A)  True
B)  False
C)  Can not Say
D)  None of the above

Correct Answer :   False

83 .
A 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.
A)  Agree
B)  Disagree
C)  Can not Say
D)  None of the above

Correct Answer :   Agree

84 .
A flow in which the viscosity of fluid is dominating over the inertia force is called
A)  steady flow
B)  unsteady flow
C)  turbulent flow
D)  laminar flow

Correct Answer :   laminar flow

85 .
An air vessel is provided at the summit in a syphon to
A)  increase velocity
B)  avoid interruption in the flow
C)  increase discharge
D)  maintain pressure difference

Correct Answer :   avoid interruption in the flow

86 .
When a tube of smaller diameter is dipped in water, the water rises in the tube with an upward __________ surface.
A)  concave
B)  convex
C)  Can not Say
D)  None of the above

Correct Answer :   concave

87 .
An orifice is said to be large, if
A)  the velocity of flow is large
B)  the size of orifice is large
C)  the available head of liquid is more than 5 times the height of orifice
D)  the available head of liquid is less than 5 times the height of orifice

Correct Answer :   the available head of liquid is less than 5 times the height of orifice

88 .
The critical depth meter is used to measure
A)  hydraulic jump
B)  depth of channel
C)  depth of flow in an open channel
D)  velocity of flow in an open channel

Correct Answer :   hydraulic jump

89 .
The flow in a pipe or channel is said to be uniform when
A)  each liquid particle has a definite path
B)  the quantity of liquid flowing per second is constant
C)  the liquid particles at all sectons have the same velocities
D)  the liquid particles at different sections have different velocities

Correct Answer :   the liquid particles at all sectons have the same velocities

90 .
The hammer blow in pipes occurs when
A)  there is excessive leakage in the pipe
B)  the pipe bursts under high pressure of fluid
C)  the flow of fluid through the pipe is gradually brought to rest by closing of the valve
D)  the flow of fluid through the pipe is suddenly brought to rest by closing of the valve

Correct Answer :   the flow of fluid through the pipe is suddenly brought to rest by closing of the valve

91 .
When a body is placed over a liquid, it will sink down if
A)  gravitational force is equal to the upthrust of the liquid
B)  gravitational force is more than the upthrust of the liquid
C)  gravitational force is less than the upthrust of the liquid
D)  None of the above

Correct Answer :   gravitational force is more than the upthrust of the liquid

92 .
A flow whose streamline is represented by a curve, is called
A)  one-dimensional flow
B)  two-dimensional flow
C)  three-dimensional flow
D)  four-dimensional flow

Correct Answer :   two-dimensional flow

93 .
When the Mach number is less than unity, the flow is called
A)  sub-sonic flow
B)  sonic flow
C)  super-sonic flow
D)  hyper-sonic flow

Correct Answer :   sub-sonic flow

94 .
When the end contractions of the weir are suppressed, then number of end contractions (n) are taken as zero
A)  Agree
B)  Disagree
C)  Can not Say
D)  None of the above

Correct Answer :   Agree

95 .
Which of the following statement is correct ?
A)  In a compressible flow, the volume of the flowing liquid changes during the flow.
A)  
B)  A flow in which the volume of the flowing liquid does not change, is called incompressible flow.
B)  
C)  When the particles rotate about their own axes while flowing, the flow is said to be rotational flow.
C)  
D)  All of the above
D)  

Correct Answer :   All of the above

96 .
A venturiflume is a flumed structure constructed across a channel by restricting its width.
A)  True
B)  False
C)  Can not Say
D)  None of the above

Correct Answer :   True

97 .
The water hammer in pipes occurs due to sudden change in the velocity of flowing liquid
A)  Agree
B)  Disagree
C)  Can not Say
D)  None of the above

Correct Answer :   Agree

98 .
One stoke is equal to_____.
A)  10⁻⁶ m²/s
A)  
B)  10⁻⁴ m²/s
B)  
C)  10⁻³ m²/s
C)  
D)  10⁻² m²/s
D)  

Correct Answer :   10⁻⁴ m²/s

99 .
The celerity (velocity) of a pressure wave in a fluid is given by (where K = Bulk modulus, and ρ = Density of the fluid)
A)  K.ρ
B)  √K/ρ
C)  √ρ/K
D)  √K.ρ

Correct Answer :   √K/ρ

100 .
The pressure intensity in kN/m² (or kPa) at any point in a liquid is (where w = Specific weight of liquid, and h = Depth of liquid from the surface)
A)  w
A)  
B)  w/h
B)  
C)  wh
C)  
D)  h/w
D)  

Correct Answer :   wh

101 .
Barometer is used to measure_____.
A)  velocity of liquid
B)  pressure in pipes and channels
C)  atmospheric pressure
D)  difference of pressure between two points in a pipe

Correct Answer :   atmospheric pressure

102 .
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.
A)  Correct
B)  Incorrect
C)  Can not Say
D)  None of the above

Correct Answer :   Correct

103 .
The region between the separation streamline and the boundary surface of the solid body is known as
A)  Drag
B)  Wake
C)  Lift
D)  Boundary layer

Correct Answer :   Wake

104 .
The horizontal component of buoyant force is
A)  Negligible
B)  Same as buoyant force
C)  Zero
D)  None of the above

Correct Answer :   Zero

105 .
Stagnation point is the point in fluid mechanics where the velocity of the fluid at that point is _____
A)  zero
B)  unity
C)  constant
D)  infinite

Correct Answer :   zero

Explanation : Stagnation point is the point in fluid mechanics where the velocity of the fluid at that point is zero. Stagnation points occur at places where the fluid is brought to a state of rest by an object. They usually exist at the surface of objects.

106 .
Which among the following is the standard symbol for Archimedes number?
A)  a
B)  A
C)  Ar
D)  AR

Correct Answer :   Ar

Explanation : The standard symbol for Archimedes number is Ar. Archimedes number in fluid mechanics deals with the motion of fluids. This takes place due to the differences in their densities. It was followed by the Archimedes principle.

107 .
Which among the following is referred to as the temperature at a stagnation point in the flow of fluids in fluid mechanics and thermodynamics.
A)  Absolute temperature
B)  Maximum temperature
C)  Hydraulic temperature
D)  Stagnation temperature

Correct Answer :   Stagnation temperature

Explanation : Stagnation temperature is the temperature at the stagnation point of the flow of fluids. In thermodynamics and fluid mechanics, these terms find application. At a stagnation point the speed of the fluid is zero and all of the kinetic energy has been converted to internal energy and is added to the local static enthalpy.

108 .
What is model testing?
A)  Overall testing
B)  Performance testing
C)  Partial testing
D)  Function testing

Correct Answer :   Performance testing

Explanation : The process in fluid mechanics that is used to study the complex fluid dynamics is called as model testing. It is a performance testing. It helps to test models after a standard scaling. Models are usually smaller than the final design.

109 .
When an internal mouthpiece is running full, the discharge through the mouthpiece is twice the discharge when it is running free.
A)  Correct
B)  Incorrect
C)  Can not Say
D)  None of the above

Correct Answer :   Incorrect

110 .
In order to avoid tendency of separation at throat in a venturimeter, the ratio of the diameter at throat to the diameter of pipe should be
A)  1/3 to 1/2
B)  1/4 to 1/3
C)  1/8 to 1/4
D)  1/16 to 1/8

Correct Answer :   1/3 to 1/2

111 .
The ratio of the inertia force to the __________ is called Euler's number.
A)  elastic force
B)  viscous force
C)  pressure force
D)  surface tension force

Correct Answer :   pressure force

112 .
The separation of flow occurs when the hydrodynamic boundary layer thickness is reduced to zero.
A)  Agree
B)  Disagree
C)  Can not Say
D)  None of the above

Correct Answer :   Agree

113 .
If the depth of water in an open channel is less than the critical depth, the flow is called
A)  tranquil flow
B)  critical flow
C)  turbulent flow
D)  torrential flow

Correct Answer :   torrential flow

114 .
A nozzle placed at the end of a water pipe line discharges water at a
A)  low velocity
B)  high velocity
C)  low pressure
D)  high pressure

Correct Answer :   high velocity

115 .
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
A)  Pascal's law
B)  Bernoulli's theorem
C)  Archimede's principle
D)  principle of floatation

Correct Answer :   Archimede's principle

116 .
The coefficient of discharge for an external mouthpiece is
A)  0.855
B)  0.707
C)  0.56
D)  0.375

Correct Answer :   0.855

117 .
A siphon is used to connect two reservoirs at different levels intervened by a high ridge.
A)  True
B)  False
C)  Can not Say
D)  None of the above

Correct Answer :   True

118 .
A flow in which the volume of a fluid and its density does not change during the flow is called __________ flow.
A)  compressible
B)  incompressible
C)  Can not Say
D)  None of the above

Correct Answer :   incompressible

119 .
The loss of head due to an obstruction in a pipe is twice the loss of head at its entrance.
A)  Agree
B)  Disagree
C)  Can not Say
D)  None of the above

Correct Answer :   Agree

120 .
The centre of gravity of the volume of the liquid displaced is called
A)  metacentre
B)  centre of pressure
C)  centre of buoyancy
D)  None of the above

Correct Answer :   centre of buoyancy

121 .
The stability of a dam is checked for
A)  tension at the base
B)  sliding of the wall or dam
C)  overturning of the wall or dam
D)  All of the above

Correct Answer :   All of the above

122 .
A manometer is used to measure_____.
A)  low pressure
B)  high pressure
C)  moderate pressure
D)  atomospheric pressure

Correct Answer :   high pressure

123 .
Which of the following is an example of laminar flow?
A)  Under ground flow
B)  Flow past tiny bodies
C)  Flow of oil in measuring instruments
D)  All of the above

Correct Answer :   All of the above

124 .
The maximum efficiency of transmission through a pipe is
A)  66.67%
B)  76.66%
C)  50%
D)  56.7%

Correct Answer :   66.67%

125 .
A structure whose width is __________ the width of the channel, is called a flumed structure.
A)  less than
B)  more than
C)  Can not Say
D)  None of the above

Correct Answer :   less than

126 .
The pressure less than atmospheric pressure is known as
A)  vacuum pressure
B)  suction pressure
C)  negative gauge pressure
D)  All of the above

Correct Answer :   All of the above

127 .
The total energy line lies over the hydraulic gradient line by an amount equal to the
A)  pressure head
B)  velocity head
C)  pressure head - velocity head
D)  pressure head + velocity head

Correct Answer :   velocity head

128 .
The viscosity of water at 20°C is
A)  one poise
B)  one stoke
C)  one centipoise
D)  one centistroke

Correct Answer :   one centipoise

129 .
The discharge through a channel of rectangular section will be maximum, if
A)  its breadth is twice the depth
B)  its depth is twice the breadth
C)  its depth is thrice the breadth
D)  its breadth is thrice the depth

Correct Answer :   its breadth is twice the depth

130 .
The rise of liquid along the walls of a revolving cylinder about the initial level is __________ the depression of the liquid at the axis of rotation.
A)  same as
B)  less than
C)  more than
D)  None of the above

Correct Answer :   same as

131 .
The theoretical velocity of jet at vena contracta is (where H = Head of water at vena contracta)
A)  2gH
B)  √2gH
C)  H√2g
D)  2g√H

Correct Answer :   √2gH

132 .
According to Newton's law of viscosity, the shear stress on a layer of a fluid is __________ to the rate of shear strain.
A)  equal to
B)  inversely proportional
C)  directly proportional
D)  All of the above

Correct Answer :   directly proportional

133 .
The intensity of pressure at any point, in a liquid, is __________ to the depth of liquid from the surface.
A)  equal
B)  directly proportional
C)  inversely proportional
D)  None of the above

Correct Answer :   directly proportional

134 .
The shear stress-strain graph for a non-newtonian fluid is a curve.
A)  Correct
B)  Incorrect
C)  Can not Say
D)  None of the above

Correct Answer :   Correct

135 .
The force per unit length is the unit of
A)  viscosity
B)  capillarity
C)  surface tension
D)  compressibility

Correct Answer :   surface tension

136 .
The velocity at which the laminar flow stops, is known as
A)  velocity of approach
B)  higher critical velocity
C)  Both (A) and (B)
D)  lower critical velocity

Correct Answer :   lower critical velocity

137 .
A weir is usually made of masonry or concrete.
A)  Yes
B)  No
C)  Can not Say
D)  None of the above

Correct Answer :   Yes

138 .
The Euler's equation for the motion of liquids is based upon the assumption that
A)  the velocity of flow is uniform over the section
B)  the flow is continuous, steady and along the stream line
C)  the fluid is non - viscous, homogeneous and incompressible
D)  All of the above

Correct Answer :   All of the above

139 .
When a cylindrical vessel, containing some liquid, is rotated about its vertical axis, the liquid surface is depressed down at the axis of its rotation and rises up near the walls of the vessel on all sides. This type of flow is known as
A)  steady flow
A)  
B)  vortex flow
B)  
C)  uniform flow
C)  
D)  turbulent flow
D)  

Correct Answer :   vortex flow

140 .
The Newton's law of resistance is based on the assumption that the
A)  planes of the body are completely smooth
B)  space around the body is completely filled with the fluid
C)  fluid particles do not exert any influence on one another
D)  All of the above

Correct Answer :   All of the above

141 .
A glass tube of smaller diameter is used while performing an experiment for the capillary rise of water because
A)  glass tube is cheaper than a metallic tube
B)  it is easier to see through the glass tube
C)  it is not possible to conduct this experiment with any other tube
D)  All of the above

Correct Answer :   it is easier to see through the glass tube

142 .
The viscosity of a liquid is due to cohesion of its particles.
A)  Correct
B)  Incorrect
C)  Can not Say
D)  None of the above

Correct Answer :   Correct

143 .
A compound pipe is required to be replaced by a new pipe. The two pipes are said to be equivalent, if
A)  length of both the pipes is same
B)  diameter of both the pipes is same
C)  loss of head and discharge of both the pipes is same
D)  loss of head and velocity of flow in both the pipes is same

Correct Answer :   loss of head and discharge of both the pipes is same

144 .
The viscosity of water is __________ than that of mercury.
A)  higher
B)  lower
C)  Can not Say
D)  None of the above

Correct Answer :   higher

145 .
In a footstep bearing, if the speed of the shaft is doubled, then the torque required to overcome the viscous resistance will be
A)  double
B)  four times
C)  eight times
D)  sixteen times

Correct Answer :   double

146 .
An open tank containing liquid is made to move from rest with a uniform acceleration. The angle 0 which the free surface of liquid makes with the horizontal is such that (where a = Horizontal acceleration of the tank, and g = Acceleration due to gravity)
A)  tan θ = 2 a/g
A)  
B)  tan θ = a/2g
B)  
C)  tan θ = a/g
C)  
D)  tan θ = a²/2g
D)  

Correct Answer :   tan θ = a/g

147 .
The discharge over a triangular notch is
A)  inversely proportional to H5/2
A)  
B)  directly proportional to H5/2
B)  
C)  directly proportional to H3/2
C)  
D)  inversely proportional to H3/2
D)  

Correct Answer :   directly proportional to H5/2

148 .
The discharge through an external mouthpiece is given by (where a = Cross-sectional area of the mouthpiece, and H = Height of liquid above the mouthpiece)
A)  5.85 aH√2g
B)  1.585 a√2gH
C)  1.855 aH√2g
D)  0.855 a√2gH

Correct Answer :   0.855 a√2gH

149 .
The flow of water through the hole in the bottom of a wash basin is an example of
A)  steady flow
B)  free vortex
C)  uniform flow
D)  forced vortex

Correct Answer :   free vortex

150 .
The loss of pressure head in case of laminar flow is proportional to
A)  velocity
B)  (velocity)²
C)  (velocity)³
D)  (velocity)⁴

Correct Answer :   velocity

151 .
The water pressure per metre length on a vertical masonry wall of dam is (where w = Specific weight of the liquid, and H = Height of the liquid)
A)  wH
B)  wH/2
C)  wH²/2
D)  wH²/4

Correct Answer :   wH²/2

152 .
The pressure of fluid due to hammer blow is
A)  directly proportional to density of fluid
B)  inversely proportional to density of fluid
C)  directly proportional to (density)½ of fluid
D)  inversely proportional to (density)½ of fluid

Correct Answer :   directly proportional to (density)½ of fluid

153 .
When a liquid is flowing through a pipe, the velocity of the liquid is
A)  zero at the centre and maximum near the walls
B)  maximum at the centre and zero near the walls
C)  minimum at the centre and maximum near the walls
D)  maximum at the centre and minimum near the walls

Correct Answer :   maximum at the centre and minimum near the walls

154 .
Froude's number is the ratio of inertia force to
A)  elastic force
B)  gravity force
C)  pressure force
D)  surface tension force

Correct Answer :   gravity force

155 .
According to Chezy's formula, the discharge through an open channel is (where A = Area of flow, C = Chezy's constant, m = Hydraulic mean depth, and i = Uniform slope in bed)
A)  A √m x i
A)  
B)  C √m x i
B)  
C)  AC √m x i
C)  
D)  mi √A x C
D)  

Correct Answer :   AC √m x i

156 .
A flow in which each liquid particle has a definite path, and the paths of individual particles do not cross each other, is called
A)  uniform flow
B)  turbulent flow
C)  streamline flow
D)  steady flow

Correct Answer :   streamline flow

157 .
An average value of coefficient of velocity is
A)  0.62
B)  0.76
C)  0.84
D)  0.97

Correct Answer :   0.97

158 .
A body floating in a liquid is said to be in neutral equilibrium, if its metacentre
A)  coincides with its centre of gravity
B)  lies below its centre of gravity
C)  lies above its centre of gravity
D)  lies between the centre of buoyancy and centre of gravity

Correct Answer :   coincides with its centre of gravity

159 .
One cubic metre of water weighs
A)  100 litres
B)  250 litres
C)  500 litres
D)  1000 litres

Correct Answer :   1000 litres

160 .
The intensity of pressure at any point, in a liquid, is
A)  inversely proportional to the depth of liquid from the surface
B)  directly proportional to the depth of liquid from the surface
C)  directly proportional to the area of the vessel containing liquid
D)  directly proportional to the length of the vessel containing liquid

Correct Answer :   directly proportional to the depth of liquid from the surface

161 .
The liquid used in manometers should have
A)  low density
B)  high density
C)  high surface tension
D)  low surface tension

Correct Answer :   high surface tension

162 .
A submerged body is said to be in a stable equilibrium, if its centre of gravity __________ the centre of buoyancy.
A)  lies below
B)  lies above
C)  coincides with
D)  None of the above

Correct Answer :   lies below

163 .
If the depth of water in an open channel is greater than the critical depth, the flow is called
A)  critical flow
B)  turbulent flow
C)  tranquil flow
D)  torrential flow

Correct Answer :   tranquil flow

164 .
The viscosity of a liquid __________ its rate of flow through a hole in a vessel.
A)  effects
B)  does not effect
C)  Can not Say
D)  None of the above

Correct Answer :   effects

165 .
The formula for discharge over a sharp-crested weir and Ogee weir is same as that of a rectangular weir
A)  Agree
B)  Disagree
C)  Can not Say
D)  None of the above

Correct Answer :   Agree

166 .
Gauge pressure at a point is equal to the absolute pressure __________ the atmospheric pressure.
A)  plus
B)  minus
C)  Can not Say
D)  None of the above

Correct Answer :   minus

167 .
The Cippoletti weir is a __________ weir.
A)  circular
B)  triangular
C)  trapezoidal
D)  rectangular

Correct Answer :   trapezoidal

168 .
When a body is placed over a liquid, it will float if
A)  gravitational force is less than the upthrust of the liquid
B)  gravitational force is more than the upthrust of the liquid
C)  gravitational force is equal to the upthrust of the liquid
D)  None of the above

Correct Answer :   gravitational force is equal to the upthrust of the liquid

169 .
The power transmitted through the pipe is maximum when the head lost due to friction is equal to
A)  one-half of the total supply head
B)  two-third of the total supply head
C)  one-fourth of the total supply head
D)  one-third of the total supply head

Correct Answer :   one-third of the total supply head

170 .
The flow in a pipe is laminar, when Reynold number is less than 2000.
A)  True
B)  False
C)  Can not Say
D)  None of the above

Correct Answer :   True

171 .
The velocity corresponding to Reynold number of 2000 is called
A)  higher critical velocity
B)  lower critical velocity
C)  sub-sonic velocity
D)  super-sonic velocity

Correct Answer :   lower critical velocity

172 .
The specific weight of water in S.I. units is taken as
A)  9.81 kN/m³
B)  9.81 x 10³ kN/m³
C)  9.81 x 10⁻⁶ N/mm³
D)  None of the above

Correct Answer :   9.81 kN/m³

173 .
The most economical section of a trapezoidal channel is one which has hydraulic mean depth equal to
A)  1/2 depth
B)  1/2 breadth
C)  1/2 sloping side
D)  1/4 (depth + breadth)

Correct Answer :   1/2 depth

174 .
Select the correct statement
A)  Weber's number is the ratio of inertia force to elastic force.
A)  
B)  Weber's number is the ratio of viscous force to pressure force.
B)  
C)  Weber's number is the ratio of inertia force to surface tension force.
C)  
D)  Weber's number is the ratio of gravity force to surface tension force.
D)  

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

175 .
The force exerted by a moving fluid on an immersed body is directly proportional to the rate of change of momentum due to the presence of the body. This statement is called
A)  Newton's law of motion
B)  Newton's law of cooling
C)  Newton's law of viscosity
D)  Newton's law of resistance

Correct Answer :   Newton's law of resistance

176 .
The specific weight of sea water is __________ that of pure water.
A)  same as
B)  less than
C)  more than
D)  None of the above

Correct Answer :   more than

177 .
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.
A)  stable
B)  neutral
C)  unstable
D)  None of the above

Correct Answer :   neutral

178 .
The mass of 2.5 m³ of a certain liquid is 2 tonnes. Its mass density is
A)  200 kg/m³
A)  
B)  400 kg/m³
B)  
C)  600 kg/m³
C)  
D)  800 kg/m³
D)  

Correct Answer :   800 kg/m³

179 .
The increase in pressure at the outer edge of a drum of radius (r) completely filled up with liquid of density (ρ) and rotating at (ω) rad/s is
A)  ρ ω² r²
B)  2ρ ω² r²
C)  ρ ω² r²/2
D)  ρ ω² r²/4

Correct Answer :   ρ ω² r²/2

180 .
When the Mach number is between __________ the flow is called super-sonic flow.
A)  1 and 6
B)  4 and 6
C)  1 and 2.5
D)  2.5 and 4

Correct Answer :   1 and 6

181 .
The dynamic viscosity of the liquid __________ with rise in temperature.
A)  increases
B)  decreases
C)  remain unaffected
D)  None of the above

Correct Answer :   decreases

182 .
When a vertical wall is subjected to pressures due to liquid on both sides, the resultant pressure is the __________ of the two pressures.
A)  sum
B)  geometric mean
C)  arithmatic mean
D)  difference

Correct Answer :   difference

183 .
The kinematic viscosity of an oil (in stokes) whose specific gravity is 0.95 and viscosity 0.011 poise, is
A)  0.0116 stoke
B)  0.0611 stoke
C)  0.116 stoke
D)  0.611 stoke

Correct Answer :   0.0116 stoke

184 .
According to Bazin, the coefficient of discharge varies with the height of water over the sill of a weir.
A)  Correct
B)  Incorrect
C)  Can not Say
D)  None of the above

Correct Answer :   Correct

185 .
If the coefficient of discharge is 0.6, then the discharge over a right angled notch is
A)  0.417 H5/2
A)  
B)  1.417 H5/2
B)  
C)  4.171 H5/2
C)  
D)  7.141 H5/2
D)  

Correct Answer :   1.417 H5/2

186 .
The factional resistance of a pipe varies approximately with __________ of the liquid.
A)  velocity
B)  pressure
C)  square of velocity
D)  cube of velocity

Correct Answer :   square of velocity

187 .
The total pressure on the top of a closed cylindrical vessel competely filled up with a liquid is
A)  inversely proportional to (radius)⁴
B)  directly proportional to (radius)⁴
C)  directly proportional to (radius)²
D)  inversely proportional to (radius)²

Correct Answer :   directly proportional to (radius)⁴

188 .
Poise is the unit of viscosity in C.G.S. system of units.
A)  Agree
B)  Disagree
C)  Can not Say
D)  None of the above

Correct Answer :   Agree

189 .
The discharge over a rectangular notch is (where b = Width of notch, and H = Height of liquid, above the sill of the notch)
A)  2/3 Cd x b√2gH
A)  
B)  23 Cd x b√2g x H
B)  
C)  2/3 Cd x b√2g x H2
C)  
D)  2/3 Cd x b√2g x H3/2
D)  

Correct Answer :   2/3 Cd x b√2g x H3/2

190 .
The discharge through a siphon spillway is
A)  Cd x a√2gH
A)  
B)  Cd x a√2g x H3/2
B)  
C)  Cd x a√2g x H2
C)  
D)  Cd x a√2g x H5/2
D)  

Correct Answer :   Cd x a√2gH

191 .
The maximum discharge over a broad crested weir is
A)  0.384 Cd x L x H1/2
A)  
B)  0.384 Cd x L x H3/2
B)  
C)  1.71 Cd x L x H3/2
C)  
D)  1.71 Cd x L x H1/2
D)  

Correct Answer :   1.71 Cd x L x H3/2

192 .
According to Francis formula, the discharge over a rectangular weir is (where n = Number of end contractions)
A)  2/3 Cd(L - nH)√2gH
A)  
B)  2/3 Cd(L - nH)√2gH2
B)  
C)  2/3 Cd(L - 0.2nH)√2gH5/2
C)  
D)  2/3 Cd(L - 0.1nH)√2gH3/2
D)  

Correct Answer :   2/3 Cd(L - 0.1nH)√2gH3/2

193 .
The specific weight is also known as weight density.
A)  Correct
B)  Incorrect
C)  Can not Say
D)  None of the above

Correct Answer :   Correct

194 .
The velocity of the liquid flowing through the divergent portion of a venturimeter
A)  increases
B)  decreases
C)  remains constant
D)  depends upon mass of liquid

Correct Answer :   decreases

195 .
In a broad-crested weir, the discharge is maximum if the head of water on the downstream side of weir is __________ the head of water on the upstream side of weir.
A)  equal to
B)  one-third
C)  two-third
D)  three-fourth

Correct Answer :   two-third

196 .
Bernoulli's equation is applied to
A)  pitot tube
B)  venturimeter
C)  orifice meter
D)  All of the above

Correct Answer :   All of the above

197 .
In the manufacturing of lead shots, the property of surface tension is utilised.
A)  Agree
B)  Disagree
C)  Can not Say
D)  None of the above

Correct Answer :   Agree

198 .
The loss of head due to friction in a pipe of uniform diameter in which a viscous flow is taking place, is (where RN = Reynold number)
A)  64/RN
B)  16/RN
C)  4/RN
D)  1/RN

Correct Answer :   16/RN

199 .
The discharge through a convergent mouthpiece is __________ the discharge through an internal mouthpiece of the same diameter and head of water.
A)  one-half
B)  double
C)  equal to
D)  three fourth

Correct Answer :   double

200 .
When the Mach number is more than 6, the flow is called
A)  sonic flow
B)  sub-sonic flow
C)  super-sonic flow
D)  hyper-sonic flow

Correct Answer :   hyper-sonic flow

201 .
The discharge through a channel of circular section will be maximum when the depth of water is __________ the diameter of the circular channel.
A)  0.67 times
B)  0.81 times
C)  0.95 times
D)  0.99 times

Correct Answer :   0.95 times

202 .
The Francis formula for the discharge over Cippoletti weir is
A)  1.84 LH
A)  
B)  1.84 LH1/2
B)  
C)  1.84 LH3/2
C)  
D)  1.84 LH5/2
D)  

Correct Answer :   1.84 LH3/2

203 .
The tendency of a liquid to uplift a submerged body, because of the upward thrust of the liquid, is known as buoyancy.
A)  Agree
B)  Disagree
C)  Can not Say
D)  None of the above

Correct Answer :   Agree

204 .
The shear stress between the two liquid layers is __________ proportional to the distance between two layers.
A)  directly
B)  indirectly
C)  Can not Say
D)  None of the above

Correct Answer :   indirectly

205 .
The mass per unit volume of a liquid at a standard temperature and pressure is called
A)  mass density
B)  specific weight
C)  specific gravity
D)  None of the above

Correct Answer :   mass density

206 .
A flow through an expanding tube at constant rate is called
A)  steady uniform flow
B)  unsteady uniform flow
C)  unsteady non-uniform flow
D)  steady non-uniform flow

Correct Answer :   steady non-uniform flow

207 .
The length of a liquid stream while flowing over a weir __________ at the ends of the sill.
A)  expands
B)  contracts
C)  does not change
D)  None of the above

Correct Answer :   contracts

208 .
In a footstep bearing, if the radius of the shaft is doubled, then the torque required to overcome the viscous resistance will be
A)  double
B)  four times
C)  eight times
D)  sixteen times

Correct Answer :   sixteen times

209 .
The velocity through a channel of circular section will be maximum when the depth of water is __________ the diameter of the circular channel.
A)  0.34 times
B)  0.67 times
C)  0.81 times
D)  0.95 times

Correct Answer :   0.81 times

210 .
Select the wrong statement
A)  The length of an equivalent pipe is equal to that of a compound pipe
A)  
B)  The diameter of an equivalent pipe is equal to that of a compound pipe
B)  
C)  An equivalent pipe is treated as an ordinary pipe for all calculations
C)  
D)  The discharge through an equivalent pipe is equal to that of a compound pipe
D)  

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

211 .
The pressure of a liquid measured with the help of a piezometer tube is
A)  gauge pressure
B)  vacuum pressure
C)  absolute pressure
D)  atmospheric pressure

Correct Answer :   gauge pressure

212 .
The hydraulic gradient line lies over the centre line of the pipe by an amount equal to the
A)  velocity head
B)  pressure head
C)  pressure head + velocity head
D)  pressure head - velocity head

Correct Answer :   pressure head

213 .
A flow whose streamline is represented by a straight line, is called __________ dimensional flow.
A)  one
B)  two
C)  three
D)  four

Correct Answer :   one

214 .
The ratio of the inertia force to the viscous force is called
A)  Weber's number
B)  Euler's number
C)  Froude's number
D)  Reynold's number

Correct Answer :   Reynold's number

215 .
The flow in a pipe or channel is said to be non-uniform when
A)  each liquid particle has a definite path
B)  the quantity of liquid flowing per second is constant
C)  the liquid particles at different sections have different velocities
D)  the liquid particles at all sections have the same velocities

Correct Answer :   the liquid particles at different sections have different velocities

216 .
A flow is called sub-sonic, if the Mach number is
A)  unity
B)  less than unity
C)  between 1 and 6
D)  more than 6

Correct Answer :   less than unity

217 .
The velocity at which the flow changes from laminar flow to turbulent flow is called
A)  critical velocity
B)  sub-sonic velocity
C)  velocity of approach
D)  super-sonic velocity

Correct Answer :   critical velocity

218 .
The discharge through a channel of trapezoidal section is maximum when
A)  depth of channel is equal to the width at the bottom
B)  the sloping side is equal to half the width at the top
C)  the sloping side is equal to the width at the bottom
D)  width of channel at the top is equal to twice the width at the bottom

Correct Answer :   the sloping side is equal to half the width at the top

219 .
The vacuum pressure is always the negative gauge pressure.
A)  Yes
B)  No
C)  Can not Say
D)  None of the above

Correct Answer :   Yes

220 .
The value of coefficient of discharge is __________ the value of coefficient of velocity.
A)  less than
B)  same as
C)  more than
D)  None of the above

Correct Answer :   less than

221 .
When the water level on the downstream side of a weir is above the top surface of a weir, the weir is known as
A)  Ogee weir
B)  broad-crested weir
C)  submerged weir
D)  narrow-crested weir

Correct Answer :   submerged weir

222 .
Reynold's number is the ratio of the inertia force to the
A)  gravity force
B)  elastic force
C)  surface tension force
D)  viscous force

Correct Answer :   viscous force

223 .
Turbulent flow takes place at high velocities.
A)  Agree
B)  Disagree
C)  Can not Say
D)  None of the above

Correct Answer :   Agree

224 .
The total pressure on an immersed surface inclined at an angle θ with the liquid surface is
A)  wx
B)  wAx
C)  wA
D)  wAx/sin θ

Correct Answer :   wAx

225 .
A uniform body 3 m long, 2 m wide and 1 m deep floats in water. If the depth of immersion is 0.6 m, then the weight of the body is
A)  3.53 kN
B)  33.3 kN
C)  35.3 kN
D)  None of the above

Correct Answer :   35.3 kN

226 .
The discharge of a depressed nappe is 6 to 7 percent __________ that of a free nappe.
A)  less than
B)  more than
C)  Can not Say
D)  None of the above

Correct Answer :   more than

227 .
The intensity of pressure on an immersed surface __________ with the increase in depth.
A)  increases
B)  decreases
C)  does not change
D)  None of the above

Correct Answer :   increases

228 .
The flow in a pipe is neither laminar nor turbulent when Reynold number is
A)  less than 2000
B)  more than 2800
C)  between 2000 and 2800
D)  None of the above

Correct Answer :   between 2000 and 2800

229 .
Re-entrant or Borda's mouthpiece is an __________ mouthpiece.
A)  internal
B)  external
C)  Can not Say
D)  None of the above

Correct Answer :   internal

230 .
According to Pascal's law, the intensity of pressure at any point in a fluid at rest is the same in all directions.
A)  Agree
B)  Disagree
C)  Can not Say
D)  None of the above

Correct Answer :   Agree

231 .
The buoyancy depends upon the
A)  viscosity of the liquid
B)  weight of the liquid displaced
C)  compressibility of the liquid
D)  pressure with which the liquid is displaced

Correct Answer :   weight of the liquid displaced

232 .
For a perfect incompressible liquid, flowing in a continuous stream, the total energy of a particle remains the same, while the particle moves from one point to another. This statement is called
A)  Pascal's law
B)  continuity equation
C)  Bernoulli's equation
D)  Archimede's principle

Correct Answer :   Bernoulli's equation

233 .
In an internal mouthpiece, the absolute pressure head at vena contracta is __________ the atmospheric pressure head by an amount equal to height of the liquid above the vena contracta.
A)  less than
B)  more than
C)  Can not Say
D)  None of the above

Correct Answer :   less than

234 .
When the coefficient of discharge (Cd) is 0.623, then the general equation for discharge over a rectangular weir is
A)  1.84(L - nH)H²
A)  
B)  1.84(L - nH)H³
B)  
C)  1.84(L - 0.1nH)H3/2
C)  
D)  1.84(L - 0.1nH)H5/2
D)  

Correct Answer :   1.84(L - 0.1nH)H3/2

235 .
The total energy line lies over the centre line of the pipe by an amount equal to
A)  pressure head
B)  velocity head
C)  pressure head - velocity head
D)  pressure head + velocity head

Correct Answer :   pressure head + velocity head

236 .
When a tank containing liquid moves with an acceleration in the horizontal direction, then the free surface of the liquid
A)  becomes curved
B)  remains horizontal
C)  falls on the front end
D)  falls on the back end

Correct Answer :   falls on the front end

237 .
The flow in a pipe is turbulent when Reynold number is
A)  less than 2000
B)  between 2000 and 2800
C)  more than 2800
D)  None of the above

Correct Answer :   more than 2800

238 .
A piezometer tube is used only for measuring
A)  low pressure
B)  moderate pressure
C)  high pressure
D)  vacuum pressure

Correct Answer :   moderate pressure

239 .
A manometer is used to measure
A)  pressure in pipes and channels
B)  atmospneric pressure
C)  pressure in venturimeter
D)  difference of pressures between two points in a pipe

Correct Answer :   pressure in pipes and channels

240 .
A point, in a compressible flow where the velocity of fluid is zero, is called
A)  critical point
B)  vena contracta
C)  Both (A) and (B)
D)  stagnation point

Correct Answer :   stagnation point

241 .
The product of mass and accelaration of flowing liquid is called
A)  gravity force
B)  inertia force
C)  viscous force
D)  pressure force

Correct Answer :   inertia force

242 .
Falling drops of water become spheres due to the property of
A)  capillarity of water
B)  viscosity of water
C)  surface tension of water
D)  compressibility of water

Correct Answer :   surface tension of water

243 .
The D-Alembert's principle is used for changing the dynamic equilibrium of a fluid mass, into a static equilibrium.
A)  Agree
B)  Disagree
C)  Can not Say
D)  None of the above

Correct Answer :   Agree

244 .
The total energy of a liquid particle in motion is equal to
A)  pressure energy - (kinetic energy + potential energy)
B)  potential energy - (pressure energy + kinetic energy
C)  pressure energy + kinetic energy + potential energy
D)  kinetic energy - (pressure energy + potential energy)

Correct Answer :   pressure energy + kinetic energy + potential energy

245 .
The height of a water column equivalent to a pressure of 0.15 MPa is
A)  15.3 m
B)  25.3 m
C)  35.3 m
D)  45.3 m

Correct Answer :   15.3 m

246 .
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, in the direction of flow of the liquid, is known as
A)  lift
B)  drag
C)  bulk modulus
D)  stagnation pressure

Correct Answer :   drag

247 .
When is the fluid called laminar?
A)  Low viscosity
B)  The density of the fluid is high
C)  Reynolds number is less than 2000
D)  Reynolds number is greater than 2000

Correct Answer :   Reynolds number is less than 2000

Explanation : Reynolds number is a dimensionless quantity. It helps to predict the flow pattern in fluid mechanics. At low Reynolds number, the flow has a very low density, due to which the value of Reynolds number is less than 2000.

248 .
Which among the following provides the third principle in fluid mechanics?
A)  Conservation of Heat
B)  Conservation of mass
C)  Conservation of volume
D)  Conservation of linear momentum

Correct Answer :   Conservation of linear momentum

Explanation : In fluid mechanics, the third principle is given by the conservation of linear momentum. It is in addition to the continuity of mass and conservation of energy. They are mostly seen in channel flow problems.

249 .
When a fluid is subjected to resistance, it undergoes a volumetric change due to __________
A)  Strain
B)  Adhesion
C)  Cohesion
D)  Compressibility

Correct Answer :   Compressibility

Explanation : Compressibility is defined as a measure of relative change in volume of a fluid. In fluid mechanics, it is also called as isothermal compressibility due to increase in pressure and temperature.

250 .
When the flow in an open channel is gradually varied, the flow is said to be
A)  steady non-uniform flow
B)  steady uniform flow
C)  unsteady uniform flow
D)  unsteady non-uniform flow

Correct Answer :   steady non-uniform flow

251 .
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.
A)  Correct
B)  Incorrect
C)  Can not Say
D)  None of the above

Correct Answer :   Correct

252 .
A weir, generally, used as a spillway of a dam is
A)  submerged weir
B)  broad crested weir
C)  Ogee weir
D)  narrow crested weir

Correct Answer :   Ogee weir

253 .
A thick liquid like a syrup has a __________ viscosity than a light liquid like water.
A)  lesser
B)  greater
C)  Can not Say
D)  None of the above

Correct Answer :   greater

254 .
The divergent portion of a venturimeter is made longer than convergent portion in order to
A)  to minimise frictional losses
B)  avoid the tendency of breaking away the stream of liquid
C)  Both (A) and (B)
D)  None of the above

Correct Answer :   Both (A) and (B)

255 .
A fluid whose viscosity changes with the rate of deformation or shear strain is known as non-newtonian fluid.
A)  True
B)  False
C)  Can not Say
D)  None of the above

Correct Answer :   True

256 .
The pressure of liquid at throat in a venturimeter is __________ than that at inlet.
A)  higher
B)  lower
C)  Can not Say
D)  None of the above

Correct Answer :   lower

257 .
In a venturiflume, the flow takes place at
A)  gauge pressure
B)  absolute pressure
C)  Both (A) and (B)
D)  atmospheric pressure

Correct Answer :   atmospheric pressure

258 .
The discharge in an open channel corresponding to critical depth is
A)  zero
B)  minimum
C)  maximum
D)  None of the above

Correct Answer :   maximum

259 .
According to equation of continuity,
A)  a₁v₁ = a₂v₂
B)  w₁a₁ = w₂a₂
C)  w₁v₁ = w₂v₂
D)  a₁/v₁ = a₂/v₂

Correct Answer :   a₁v₁ = a₂v₂

260 .
In order to measure the flow with a venturimeter, it is installed in
A)  any direction and in any location
B)  horizontal line
C)  inclined line with flow upwards
D)  inclined line with flow downwards

Correct Answer :   any direction and in any location

261 .
Coefficient of resistance is the ratio of
A)  area of jet at vena contracta to the area of orifice
B)  actual discharge through an orifice to the dieoretical discharge
C)  actual velocity of jet at vena contracta to the theoretical velocity
D)  loss of head in the orifice to the head of water available at the exit of the orifice

Correct Answer :   loss of head in the orifice to the head of water available at the exit of the orifice

262 .
When a tube of smaller diameter is dipped in water, the water rises in the tube due to viscosity of water.
A)  True
B)  False
C)  Can not Say
D)  None of the above

Correct Answer :   False

263 .
The Reynold's number of a ship is __________ to its velocity and length.
A)  directly proportional
B)  inversely proportional
C)  Can not Say
D)  None of the above

Correct Answer :   directly proportional

264 .
The length AB of a pipe ABC in which the liquid is flowing has diameter (d₁) and is suddenly enlarged to diameter (d₂) at B which is constant for the length BC. The loss of head due to sudden enlargement is
A)  V₁²-V₂² / g
A)  
B)  (V₁-V₂)² / g
B)  
C)  (V₁-V₂)² / 2g
C)  
D)  V₁²-V₂² / 2g
D)  

Correct Answer :   (V₁-V₂)² / 2g

265 .
Coefficient of contraction is the ratio of
A)  actual discharge through an orifice to the theoretical discharge
B)  actual velocity of jet at vena contracta to the theoretical velocity
C)  area of jet at vena contracta to the area of orifice
D)  loss of head in the orifice to the head of water available at the exit of the orifice

Correct Answer :   area of jet at vena contracta to the area of orifice

266 .
In a free nappe,
A)  the pressure below the nappe is negative
B)  the pressure below the nappe is atmospheric
C)  the pressure above the nappe is negative
D)  the pressure above the nappe is atmospheric

Correct Answer :   the pressure below the nappe is atmospheric

267 .
The most efficient section of a channel is
A)  square
B)  triangular
C)  rectangular
D)  trapezoidal

Correct Answer :   trapezoidal

268 .
The ratio of the inertia force to the elastic force is called
A)  Mach number
B)  Weber's number
C)  Froude's number
D)  Reynold's number

Correct Answer :   Mach number

269 .
An opening in the side of a tank or vessel such that the liquid surface with the tank is below the top edge of the opening, is called
A)  notch
B)  weir
C)  orifice
D)  None of the above

Correct Answer :   notch

270 .
The total pressure on the top of a closed cylindrical vessel of radius (r) completely filled up with liquid of specific weight (w) and rotating at (ω) rad/s about its vertical axis, is
A)  π w ω² r² / 4g
B)  π w ω² r³ / 4g
C)  π w ω² r⁴ / 4g
D)  π w ω² r² / 2g

Correct Answer :   π w ω² r⁴ / 4g

271 .
The coefficient of venturifiume, generally, lies between
A)  0.3 to 0.45
B)  0.95 to 1.0
C)  0.50 to 0.75
D)  0.75 to 0.95

Correct Answer :   0.95 to 1.0

272 .
Venturimeter is used to
A)  measure the pressure of a flowing liquid
B)  measure the velocity of a flowing liquid
C)  measure the pressure difference of liquid flowing between two points in a pipe line
D)  measure the discharge of liquid flowing in a pipe

Correct Answer :   measure the discharge of liquid flowing in a pipe

273 .
The force present in a moving liquid is
A)  gravity force
B)  viscous force
C)  inertia force
D)  All of the above

Correct Answer :   All of the above

274 .
A flow is called super-sonic if the
A)  velocity of flow is very high
B)  discharge is difficult to measure
C)  Mach number is between 1and 6
D)  None of the above

Correct Answer :   Mach number is between 1and 6

275 .
The specific gravity has no units.
A)  Agree
B)  Disagree
C)  Can not Say
D)  None of the above

Correct Answer :   Agree

276 .
The depth of water in a channel corresponding to the minimum specific energy is known as critical depth.
A)  Agree
B)  Disagree
C)  Can not Say
D)  None of the above

Correct Answer :   Agree

277 .
The ratio of the inertia force to the gravity force is called Froude number.
A)  Agree
B)  Disagree
C)  Can not Say
D)  None of the above

Correct Answer :   Agree

278 .
A water tank contains 1.3 m deep water. The pressure exerted by the water per metre length of the tank is
A)  2.89 kN
B)  8.29 kN
C)  9.28 kN
D)  28.9 kN

Correct Answer :   8.29 kN

279 .
Bulk modulus of a fluid __________ as the pressure increases.
A)  decreases
B)  remains same
C)  increases
D)  None of the above

Correct Answer :   increases

280 .
Reynold's number is the ratio of inertia force to
A)  gravity force
B)  elastic force
C)  pressure force
D)  viscous force

Correct Answer :   viscous force

281 .
The unit of dynamic viscosity in S.I. units is
A)  poise
B)  stoke
C)  N-m/s²
D)  N-s/m²

Correct Answer :   N-s/m²

282 .
When a plate is immersed in a liquid parallel to the flow, it will be subjected to a pressure __________ that if the same plate is immersed perpendicular to the flow.
A)  less than
B)  more than
C)  Can not Say
D)  None of the above

Correct Answer :   less than

283 .
The hydraulic mean depth for a circular pipe of diameter (d) is
A)  d
B)  d/2
C)  d/4
D)  d/6

Correct Answer :   d/4

284 .
A fluid whose viscosity does not change with the rate of deformation or shear strain is known as
A)  real fluid
B)  newtonian fluid
C)  ideal fluid
D)  non-newtonian fluid

Correct Answer :   newtonian fluid

285 .
The unit of kinematic viscosity in S. I. units is
A)  N-m
B)  m²/s
C)  N-m/s
D)  N-s/m²

Correct Answer :   m²/s

286 .
The metacentric height is the distance between the
A)  metacentre and centre of buoyancy
B)  original centre of buoyancy and new centre of buoyancy
C)  centre of gravity of the floating body and the centre of buoyancy
D)  centre of gravity of the floating body and the metacentre

Correct Answer :   centre of gravity of the floating body and the metacentre

287 .
The variation in the volume of a liquid with the variation of pressure is called its
A)  compressibility
B)  viscosity
C)  capillarity
D)  surface tension

Correct Answer :   compressibility

288 .
A venturiflume is used to measure
A)  pressure of liquid
B)  pressure difference between two points in a pipe
C)  discharge of liquid
D)  pressure difference between two points in a channel

Correct Answer :   discharge of liquid

289 .
The pressure measured with the help of a pressure gauge is called
A)  mean pressure
B)  absolute pressure
C)  gauge pressure
D)  atmospheric pressure

Correct Answer :   gauge pressure

290 .
The siphon will work satisfactorily, if the minimum pressure in the pipe is __________ vapour pressure of liquid.
A)  less than
B)  more than
C)  equal to
D)  None of the above

Correct Answer :   more than

291 .
The difference between the notch and weir is that the notch is of bigger size and the weir is of a smaller size.
A)  Agree
B)  Disagree
C)  Can not Say
D)  None of the above

Correct Answer :   Disagree

292 .
An open tank containing liquid is moving with an acceleration on an inclined plane. The inclination of the free surface of the liquid will be __________ to the acceleration of the tank.
A)  equal to
B)  inversely proportional
C)  directly proportional
D)  None of the above

Correct Answer :   directly proportional

293 .
Euler's number is the ratio of __________ force to pressure force.
A)  inertia
B)  gravity
C)  viscous
D)  None of the above

Correct Answer :   inertia

294 .
The power transmitted through the nozzle is maximum when the head lost due to friction in the pipe is __________ of the total supply head.
A)  one
B)  one-half
C)  two-third
D)  one-third

Correct Answer :   one-third

295 .
In case of flow through parallel pipes,
A)  the head loss for all the pipes is same
B)  the total discharge is equal to the sum of discharges in the various pipes
C)  Both (A) and (B)
D)  the total head loss is the sum of head losses in the various pipes

Correct Answer :   Both (A) and (B)

296 .
Coefficient of velocity is defined as the ratio of
A)  area of jet at vena contracta to the area of orifice
B)  actual velocity of jet at vena contracta to the theoretical velocity
C)  actual discharge through an orifice to the theoretical discharge
D)  None of the above

Correct Answer :   actual velocity of jet at vena contracta to the theoretical velocity

297 .
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
A)  4.1 s
B)  5.2 s
C)  7.3 s
D)  10.4 s

Correct Answer :   10.4 s

298 .
The point at which the resultant pressure on an immersed surface acts, is known as
A)  centre of pressure
B)  centre of depth
C)  centre of gravity
D)  centre of immersed surface

Correct Answer :   centre of pressure

299 .
The compressible flow is assumed to be _________
A)  Polytropic
B)  Adiabatic only
C)  Isentropic only
D)  Isentropic and adiabatic

Correct Answer :   Isentropic only

Explanation : Compressible flow is a branch of fluid mechanics that deals with different types of flow. Its main significance lies in the change in fluid density. It deals with gas dynamics. Flow is assumed to be isentropic.

300 .
Principle of fluid mechanics works on the utilization of________
A)  Work
B)  Volume
C)  Velocity
D)  Accelerating mass

Correct Answer :   Work

Explanation : The Principle of fluid mechanics works on the utilization of useful work. The working is based on the force exerted by a fluid jet striking the surface and moving over a series of vanes about its axis.

301 .
The force of buoyancy is always __________ the weight of the liquid displaced by the body.
A)  less than
B)  equal to
C)  more than
D)  None of the above

Correct Answer :   equal to

302 .
The purpose of a surge tank is
A)  to eliminate water hammer possibilities
B)  to control the pressure variations due to rapid changes in the pipe line flow
C)  to regulate flow of water to turbines by providing necessary retarding head of water
D)  All of the above

Correct Answer :   All of the above

303 .
A fluid which obeys the Newton's law of viscosity is termed as
A)  real fluid
B)  ideal fluid
C)  newtonian fluid
D)  non-newtonian fluid

Correct Answer :   newtonian fluid

304 .
The specific gravity of an oil whose specific weight is 7.85 kN/m3, is
A)  0.8
B)  1.0
C)  1.2
D)  1.6

Correct Answer :   0.8

305 .
The body will float if the force of buoyancy is __________ the weight of the liquid displaced.
A)  less than
B)  equal to
C)  more than
D)  None of the above

Correct Answer :   more than

306 .
The ratio of specific weight of a liquid to the specific weight of pure water at a standard temperature is called
A)  density of liquid
B)  specific gravity of liquid
C)  compressibility of liquid
D)  surface tension of liquid

Correct Answer :   specific gravity of liquid

307 .
The velocity of liquid flowing through an orifice varies with the available head of the liquid.
A)  Agree
B)  Disagree
C)  Can not Say
D)  None of the above

Correct Answer :   Agree

308 .
A weir is said to be broad crested weir, if the width of the crest of the weir is __________ half the height of water above the weir crest.
A)  less than
B)  equal to
C)  more than
D)  None of the above

Correct Answer :   more than

309 .
An error of 1% in measuring head over the apex of the notch (H) will produce an error of __________ in discharge over a triangular notch.
A)  1%
B)  1.5%
C)  2%
D)  2.5%

Correct Answer :   2.5%

310 .
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 per unit length is (where w = Specific weight of liquid, and H = Height of liquid)
A)  wH
B)  wH/2
C)  wH²/2
D)  wH²/3

Correct Answer :   wH²/2

311 .
One litre of water occupies a volume of
A)  100 cm³
B)  250 cm³
C)  500 cm³
D)  1000 cm³

Correct Answer :   1000 cm³

312 .
The kinematic viscosity is the
A)  product of absolute viscosity and mass of the liquid
B)  ratio of absolute viscosity to the density of the liquid
C)  product of absolute viscosity and density of the liquid
D)  ratio of density of the liquid to the absolute viscosity

Correct Answer :   ratio of absolute viscosity to the density of the liquid

313 .
In one dimensional flow, the flow
A)  takes place in straight line
B)  takes place in curve
C)  is steady and uniform
D)  takes place in one direction

Correct Answer :   takes place in straight line

314 .
The value of bulk modulus of a fluid is required to determine
A)  Froude's number
B)  Mach number
C)  Euler's number
D)  Reynold's number

Correct Answer :   Mach number

315 .
In a depressed nappe
A)  the pressure above the nappe is negative
B)  the pressure above the nappe is atmospheric
C)  the pressure below the nappe is negative
D)  the pressure below the nappe is atmospheric

Correct Answer :   the pressure below the nappe is negative

316 .
The property of a liquid which enables it to resist tensile stress is called its surface tension.
A)  Agree
B)  Disagree
C)  Can not Say
D)  None of the above

Correct Answer :   Agree

317 .
The magnitude of water hammer depends upon the
A)  speed at which the valve is closed
B)  elastic properties of the pipe material
C)  elastic properties of the liquid flowing through the pipe
D)  All of the above

Correct Answer :   All of the above

318 .
The discharge over the trapezoidal notch is equal to the discharge over the rectangular notch __________ the discharge over the triangular notch.
A)  plus
B)  minus
C)  Can not Say
D)  None of the above

Correct Answer :   plus

319 .
The dynamic viscosity of gases __________ with rise in temperature.
A)  decreases
B)  increases
C)  remain unaffected
D)  None of the above

Correct Answer :   increases

320 .
A flow in which __________ force is dominating over the viscosity is called turbulent flow.
A)  viscous
B)  elastic
C)  inertia
D)  surface tension

Correct Answer :   inertia

321 .
When the pressure intensity at a point is less than the local atmospheric pressure, then the difference of these two pressures is called vacuum pressure.
A)  Agree
B)  Disagree
C)  Can not Say
D)  None of the above

Correct Answer :   Agree

322 .
The atmospheric pressure at sea level is
A)  103 kN/m²
B)  10.3 m of water
C)  760 mm of mercury
D)  All of the above

Correct Answer :   All of the above

323 .
The velocity corresponding to Reynold number of 2800, is called
A)  sub-sonic velocity
B)  super-sonic velocity
C)  lower critical velocity
D)  higher critical velocity

Correct Answer :   higher critical velocity

324 .
When the pipes are in series, the total head loss is equal to the sum of the head loss in each pipe.
A)  Yes
B)  No
C)  Can not Say
D)  None of the above

Correct Answer :   Yes

325 .
When a cylindrical vessel containing liquid is revolved, the surface of the liquid takes the shape of
A)  an ellipse
B)  a triangle
C)  a paraboloid
D)  None of the above

Correct Answer :   a paraboloid

326 .
The most economical section of a rectangular channel is one which has hydraulic mean depth or hydraulic radius equal to
A)  twice the depth
B)  half the depth
C)  half the breadth
D)  twice the breadth

Correct Answer :   half the depth

327 .
All the gases are considered to have compressible flow and all the liquids are considered to have incompressible flow.
A)  Correct
B)  Incorrect
C)  Can not Say
D)  None of the above

Correct Answer :   Correct

328 .
A notch is used to measure __________ of liquids.
A)  volume
B)  pressure
C)  discharge
D)  velocity

Correct Answer :   discharge

329 .
The surface tension of mercury at normal temperature is __________ that of water.
A)  same as
B)  lower than
C)  higher than
D)  None of the above

Correct Answer :   higher than

330 .
A flow through a long pipe at decreasing rate is called __________ uniform flow.
A)  steady
B)  unsteady
C)  Can not Say
D)  None of the above

Correct Answer :   unsteady

331 .
Open channel flow takes place _______
A)  On a free surface
B)  In a pump
C)  In the pipe
D)  Within a cylindrical depth

Correct Answer :   On a free surface

Explanation : Open channel flow is a flow that deals with hydraulics in fluid mechanics. It is a type of liquid flow that flows through a free surface. This free surface is called as a channel. And since the channel is free, it is called as an open channel flow.

332 .
Which among the following have the same forces acting on them?
A)  Geometric similarity
B)  Kinematic similarity
C)  Conditional similarity
D)  Dynamic similarity

Correct Answer :   Dynamic similarity

Explanation : Dynamic similarities have the same forces acting on them. That means, the ratios of all the forces acting on the fluid particles are constant. Also, the ratio of the forces acting on the boundary surfaces are also a constant.

333 .
Which of the following is the mathematical technique used to predict physical parameters?
A)  Pressure analysis
B)  Dimensional analysis
C)  Combustion analysis
D)  Temperature analysis

Correct Answer :   Dimensional analysis

Explanation : Dimensional analysis is a process which is used to determine physical parameters that influence the fluid flow. The analysis is based on the fundamental units. The fundamental units are mass, length and time.

334 .
Which among the following is not global parameters of fluid?
A)  Density
B)  Viscosity
C)  External diameter
D)  Mass flow rate

Correct Answer :   External diameter

Explanation : External diameter is not a global parameter. It is one of the most essential pipelining parameters. It helps in determining the type of pipe and material to be used for the same.

335 .
The angle of taper on draft tube is
A)  Less than 8°
B)  Greater than 5°
C)  Greater than 8°
D)  Greater than 15°

Correct Answer :   Less than 8°

336 .
The working of which of the following hydraulic units is based on Pascal's law?
A)  Jet pump
B)  Air lift pump
C)  Hydraulic press
D)  Hydraulic coupling

Correct Answer :   Hydraulic press

337 .
When a body floating in a liquid, is displaced slightly, it oscillates about
A)  C.G. of body
B)  Metacentre
C)  Center of pressure
D)  Center of buoyancy

Correct Answer :   Metacentre

338 .
The optimum value of vane exit angle for a centrifugal pump impeller is
A)  10-15°
B)  20-25°
C)  30-40°
D)  50-60°

Correct Answer :   20-25°

339 .
Air vessels in reciprocating pump are used to
A)  Smoothen flow
B)  Increase pump efficiency
C)  Save pump from cavitations
D)  Reduce acceleration to minimum

Correct Answer :   Reduce acceleration to minimum

340 .
Which among the following is an assumption of Hagen-Poiseuille equation?
A)  Fluid is laminar
B)  Fluid is uniform
C)  Fluid is turbulent
D)  Fluid is compressible

Correct Answer :   Fluid is laminar

Explanation : Fluid flow is laminar as it is assumed to be incompressible and Newtonian. The flow is laminar through the pipe of constant cross section. Thus, there is no acceleration of fluid in the pipe. Therefore, Hagen-Poiseuille assumed that fluid flow is laminar.

341 .
Which of the following equation must be perfunctorily satisfied while dealing with fluid flow problems?
A)  Newton’s third law
B)  Continuity equation
C)  Newton’s second law
D)  Law of conservation of momentum

Correct Answer :   Continuity equation

Explanation : Continuity equation must be perfunctorily satisfied while dealing with fluid flow problems.

342 .
Which of the following is a type of fluid based on viscosity?
A)  Real Fluid
B)  Ideal Fluid
C)  Newtonian Fluid
D)  All of the above

Correct Answer :   All of the above

Explanation : Fluid based on viscosity :
i) Real Fluid
ii) Ideal Fluid
iii) Newtonian Fluid
iv) Non-Newtonian Fluid
v) Ideal Plastic Fluid

343 .
The viscous force the relative motion between the adjacent layers of a fluid in motion. Which of the following flowing fits best in the sentence?
A)  opposes
B)  facilitates
C)  never affects
D)  may effect under certain conditions

Correct Answer :   opposes

Explanation : Viscosity is the internal friction of a fluid in motion. It is the property by the virtue of which the relative motion between two adjacent fluid layers is opposed.

344 .
Pressure intensity or force due to pressure gradient for fluid at rest is considered as which of the following kind of force?
A)  Body force
B)  Force due to motion
C)  Surface force
D)  None of the above

Correct Answer :   Surface force

Explanation : Pressure force is surface force.

345 .
When the body is completely or partially immersed in a fluid, how much its weight be distributed for it to be in stable equilibrium.
A)  Around the upper part
B)  Around the lower part
C)  Is independent of weight distribution
D)  None of the above

Correct Answer :   Around the lower part

Explanation : When the weight distribution is around the lower part, the centre of gravity is at lower portion and hence below the centre of buoyancy which is condition for stable equilibrium.

346 .
In an outward flow reaction turbine
A)  The water flows parallel to the axis of the wheel
B)  The flow of water is partly radial and partly axial
C)  The water enters at the centre of the wheel and then flows towards the outer periphery of the wheel
D)  The water enters the wheel at the outer periphery and then flows towards the centre of the wheel

Correct Answer :   The water enters at the centre of the wheel and then flows towards the outer periphery of the wheel

347 .
In an inward flow reaction turbine
A)  The water flows parallel to the axis of the wheel
B)  The flow of water is partly radial and partly axial
C)  The water enters at the center of the wheel and then flows towards the outer periphery of the wheel
D)  The water enters the wheel at the outer periphery and then flows towards the center of the wheel

Correct Answer :   The water enters the wheel at the outer periphery and then flows towards the center of the wheel

348 .
The specific speed from 160 to 500 r.p.m. of a centrifugal pump indicates that the pump is
A)  High speed with axial flow at outlet
B)  High speed with radial flow at outlet
C)  Medium speed with radial flow at outlet
D)  Slow speed with radial flow at outlet

Correct Answer :   High speed with axial flow at outlet

349 .
The total pressure force on a plane area is equal to the area multiplied by the intensity of pressure at the Centroid, if
A)  The area is vertical
B)  The area is inclined
C)  The area is horizontal
D)  All of the above

Correct Answer :   All of the above

350 .
Which of the following principle is used for calculating the centre of pressure?
A)  Principle of momentum
B)  Principle of balancing of momentum
C)  Principle of conservation of energy
D)  None of the above

Correct Answer :   Principle of balancing of momentum

Explanation : We balance the moment in order to calculate the position of centre of pressure.

351 .
Pressure variation for compressible fluid is maximum for which of the following kind of process?
A)  Adiabatic
B)  Quasi Static
C)  Isothermal
D)  None of the above

Correct Answer :   Isothermal

Explanation : Due to constant temperature, pressure variation for compressible fluid is maximum for isothermal process.

352 .
In a centrifugal pump casing, the flow of water leaving the impeller, is
A)  Free vortex motion
B)  Radial flow
C)  Forced vortex
D)  Rectilinear flow

Correct Answer :   Free vortex motion

353 .
The flow ratio of Francis turbine is defined as the ratio of the
A)  Theoretical velocity of jet to the velocity of flow at inlet
B)  Velocity of flow at inlet to the theoretical jet velocity
C)  Velocity of runner at inlet to the velocity of flow at inlet
D)  None of the above

Correct Answer :   Velocity of flow at inlet to the theoretical jet velocity

354 .
The jet ratio is defined as the ratio of the
A)  Diameter of jet to the diameter of Pelton wheel
B)  Velocity of jet to the velocity of Pelton wheel
C)  Velocity of Pelton wheel to the velocity of jet
D)  Diameter of Pelton wheel to the diameter of jet

Correct Answer :   Diameter of Pelton wheel to the diameter of jet

355 .
The centrifugal pump preferred for a specific speed between 80 to 160 r.p.m. is
A)  Slow speed with radial flow at outlet
B)  Medium speed with radial flow at outlet
C)  High speed with mixed flow at outlet
D)  High speed with radial flow at outlet

Correct Answer :   High speed with mixed flow at outlet

356 .
Which of the following statement is correct as regard to water wheels?
A)  They have slow speeds
B)  They are suitable even for low water heads
C)  They give constant efficiency, even if the discharge is not constant
D)  All of the above

Correct Answer :   All of the above

357 .
The ratio of actual work available at the turbine to the energy imparted to the wheel is known as ________ efficiency.
A)  Mechanical
B)  Overall
C)  Hydraulic
D)  None of the above

Correct Answer :   Mechanical

358 .
If 850 kg liquid occupies volume of one cubic meter, men 0.85 represents its
A)  Specific mass
B)  Specific gravity
C)  Specific weight
D)  Specific density

Correct Answer :   Specific gravity

359 .
Which of the following turbine is preferred for a specific speed of 60 to 300 r.p.m.?
A)  Kaplan turbine
B)  Pelton wheel
C)  Francis turbine
D)  None of the above

Correct Answer :   Francis turbine

360 .
Free surface of a liquid tends to contract to the smallest possible area due to force of
A)  Friction
B)  Surface tension
C)  Viscosity
D)  Cohesion

Correct Answer :   Surface tension

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