1. Pascal-second is the unit of
a)
pressure
b) kinematic
viscosity
c)
dynamic viscosity
d) surface
tension
Ans:
c
2. An ideal fluid is
a)
one which obeys Newton's law of viscosity
b) frictionless
and incompressible
c)
very viscous
d) frictionless
and compressible
Ans: b
3. The unit of kinematic viscosity is
a)
gm/cm-sec2
b) dyne-sec/cm2
c)
gm/cm2-sec
d) cm2/sec
Ans:d
Ans:d
4.
If the dynamic viscosity of a fluid is 0.5 poise and specific gravity is 0.5,
then the kinematic viscosity of that fluid in stokes is
a) 0.25
b) 0.50
c)
1.0
d) none
of the above
Ans:
c
5. The viscosity of a gas
a)
decreases with increase in temperature
b) increases
with increase in temperature
c)
is independent of temperature
d) is
independent of pressure for very high pressure intensities
Ans: b
6. Newton's law of viscosity relates
a)
intensity of pressure and rate of angular
deformation
b) shear
stress and rate of angular deformation
c)
shear stress, viscosity and temperature
d) viscosity
and rate of angular deformation
Ans: b
7. An open tank contains 1 m deep water with
50 cm depth of oil of specific gravity 0.8 above it. The intensity of pressure
at the bottom of tank will be
a) 4
kN/m2
b) 10
kN/m2
c)
12 kN/m2
d) 14
kN/m2
Ans: d
8.The position of center of pressure on a
plane surface immersed vertically in a static mass of fluid is
a)
at the centroid of the submerged area
b) always
above the centroid of the area
c)
always below the centroid of the area
d) none
of the above
Ans: c
9. The total pressure on a plane surface
inclined at an angle 9 with the horizontal is equal to
a) PA
b) pA
sin 9
c)
pA cos 9
d) pA
tan 9 where p is pressure intensity at centroid of area and A is area of plane
surface.
Ans: a
10.
A vertical rectangular plane surface is submerged in water such that its top
and bottom surfaces are 1.5 m and 6.0 m res-pectively below the free surface.
The position of center of pressure below the free surface will be at a distance
of
a) 3.75 m
b) 4.0
m
c)
4.2m
d) 4.5m
Ans: c
11. Centre of buoyancy always
a)
coincides with the centre of gravity
b) coincides
with the centroid of the volume of fluid displaced
c)
remains above the centre of gravity
d) remains
below the centre of gravity
Ans: b
12. If the weight of a body immersed in a fluid
exceeds the buoyant force, then the body will
a) rise until its weight equals the buoyant
force
b) tend to move downward and it may finally sink
c)
float
d) none
of the above
Ans: b
13. Metacentric height for small values of
angle of heel is the distance between the
a)
centre of gravity and centre of buoy-ancy
b) centre
of gravity and metacentre
c)
centre of buoyancy and metacentre
d) free
surface and centre of buoyancy
Ans: b
14.
A floating body is said to be in a state of stable equilibrium
a)
when its metacentric height is zero
b) when
the metacentre is above the centre of gravity
c)
when the metacentre is below the centre of
gravity
d) only
when its centre of gravity is below its centre of buoyancy
Ans: b
15.The increase in meta centric height
i) increases stability
ii) decreases stability
iii)increases comfort for passengers
iv) decreases comfort for passengers
The
correct answer is
a)
(i) and (iii)
b) (i)and(iv)
c)
(ii) and (iii)
d) (ii)
and (iv)
Ans: b
11. Centre of
buoyancy always
a)
coincides with the centre of gravity
b) coincides
with the centroid of the volume of fluid displaced
c)
remains above the centre of gravity
d) remains
below the centre of gravity
Ans: b
12. If the weight
of a body immersed in a fluid exceeds the buoyant force, then the body will
a)
rise until its weight equals the buoyant force
b) tend
to move downward and it may finally sink
c)
float
d) none
of the above
Ans: b
13. Metacentric
height for small values of angle of heel is the distance between the
a)
centre of gravity and centre of buoy-ancy
b) centre
of gravity and metacentre
c)
centre of buoyancy and metacentre
d) free
surface and centre of buoyancy
Ans: b
14. A floating body is said to be in a state of stable
equilibrium
a)
when its metacentric height is zero
b) when
the metacentre is above the centre of gravity
c)
when the metacentre is below the centre of
gravity
d) only
when its centre of gravity is below its centre of buoyancy
Ans: b
15. The increase in
meta centric height
i) increases
stability
ii) decreases stability
iii) increases comfort for passengers
iv) decreases comfort for passengers
The correct answer is
iii) increases comfort for passengers
iv) decreases comfort for passengers
The correct answer is
a)
(i) and (iii)
b) (i)and(iv)
c)
(ii) and (iii)
d) (ii)
and (iv)
Ans: b
16. A rectangular block 2 m long, 1 m wide and 1 m deep
floats in water, the depth of immersion being 0.5 m. If water weighs 10 kN/m3,
then the weight of the block is
a)
5kN
b) 10kN
c)
15 kN
d) 20
kN
Ans: b
17. The point in
the immersed body through which the resultant pressure of the liquid may be
taken to act is known as
a)
center of gravity
b) center
of buoyancy
c)
center of pressure
d) metacentre
Ans: c
18. If a vessel
containing liquid moves downward with a constant acceleration equal to 'g' then
a)
the
pressure throughout the liquid mass is atmospheric
b) there
will be vacuum in the liquid
c)
the pressure in the liquid mass is greater than
hydrostatic pressure
d) none of the above
d) none of the above
Ans: a
19. When a liquid
rotates at a constant angular velocity about a vertical axis as a rigid body,
the pressure intensity varies
a)
linearly with radial distance
b) as
the square of the radial distance
c)
inversely as the square of the radial distance
d) inversely
as the radial distance
Ans: b
20. An open
cubical tank of 2 m side is filled with water. If the tank is rotated with an
acceleration such that half of the water spills out, then the acceleration is
equal to
a) g/3
a) g/3
b) g/2
c)
2g/3
d) g
Ans: d
21. A right
circular cylinder open at the top is filled with liquid and rotated about its
vertical axis at such a speed that half the liquid spills out, then the
pressure intensity at the center of bottom is
a) zero
a) zero
b) one-fourth its
value when cylinder was full
c)
one-half its value when cylinder was full
d) cannot
be predicted from the given data
Ans: a
22. The horizontal
component of force on a curved surface is equal to the
a)
product of pressure intensity at its centroid
and area
b) force
on a vertical projection of the curved surface
c)
weight of liquid vertically above the curved
surface
d) force
on the horizontal projection of the curved surface
Ans: b
Ans: b
23. A closed tank
containing water is moving in a horizontal direction along a straight line at a
constant speed. The tank also contains a steel ball and a bubble of air. If the
tank is decelerated horizontally, then
i) the ball
will move to the front
ii) the bubble will move to the front
iii) the ball will move to the rear
iv) the bubble will move to the rear
Find out which of the above statements are correct ?
a) (i) and (ii)
ii) the bubble will move to the front
iii) the ball will move to the rear
iv) the bubble will move to the rear
Find out which of the above statements are correct ?
a) (i) and (ii)
b) (i)and(iv)
c)
(ii) and (iii)
d) (iii)
and (iv)
Ans: b
24. The eddy
viscosity for turbulent flow is
a)
a function of temperature only
b) a
physical property of the fluid.
c)
dependent on the flow
d) independent
of the flow
Ans: c
25. Flow at
constant rate through a tapering pipe is
i)steady flow
ii)uniform flow
iii)unsteady flow
iv)non-uniform flow
The correct answer is
a) (i) and (ii)
i)steady flow
ii)uniform flow
iii)unsteady flow
iv)non-uniform flow
The correct answer is
a) (i) and (ii)
b) (i)and(iv)
c)
(ii) and (iii)
d) (ii)
and (iv)
Ans: b
26. In a two dimensional incompressible steady flow around
an airfoil, the stream lines are 2 cm apart at a great distance from the
airfoil, where the velocity is 30 m/sec. The velocity near the airfoil, where
the stream lines are 1.5 cm apart, is
a) 22.5 m/sec.
a) 22.5 m/sec.
b) 33
m/sec.
c)
40 m/sec.
d) 90
m/sec.
Ans: c
27. When the
velocity distribution is uniform over the cross-section, the correction factor
for momentum is
a)
0
b) 1
c)
4/3
d) 2
Ans: b
28. Least possible
value of correction factor for
i) kinetic energy is zero
ii) kinetic energy is 1
iii) momentum is zero
iv) momentum is 1
The correct statements are
i) kinetic energy is zero
ii) kinetic energy is 1
iii) momentum is zero
iv) momentum is 1
The correct statements are
a)
(i) and (iii)
b) (ii)
and (iii)
c)
(i) and (iv)
d) (ii)
and (iv)
Ans: d
29. If the velocity is zero over half of the cross-sectional
area and is uniform over the remaining half, then the momentum correction
factor is
a) 1
b) 4/3
b) 4/3
c) 2
d) 4
d) 4
Ans: c
30. If velocity is zero over l/3rd of a cross-section
and is uniform over remaining 2/3rd of the crosssection, then the correction
factor for kinetic energy is
a) 4/3
a) 4/3
b) 3/2
c)
9/4
d) 27/8
Ans: c
31. The continuity
equation : pi V,A,= p2V2A2 is based on
the following assumption regarding flow of fluid
a)
steady flow
b) uniform
flow
c)
incompressible flow
d) frictionless
flow where pi and p2 are mass densities.
Ans: a
32.Which of
the following velocity potentials satisfies continuity equation ? a) x2y
b) x2-y2
c)
cosx
d) x2
+ y2
Ans: b
33. The motion of
air mass in a tornado is a
a)
free vortex motion
b) forced
vortex motion
c)
free vortex at center and forced vortex outside
d) forced
vortex at center and free vortex outside
Ans: d
34. In a forced
vortex motion, the velocity of flow is
a)
directly proportional to its radial distance
from axis of rotation
b) inversely
proportional to its radial distance from the axis of rotation
c)
inversely proportional to the square of its
radial distance from the axis of rotation
d) directly
proportional to the square of its radial distance from the axis of rotation
Ans: a
Ans: a
35. Stream lines
and path lines always coincide in case of
a)
steady flow
b) laminar
flow
c)
uniform flow
d) turbulent
flow
Ans: a
36. Equation of continuity is based on the principle of conservation of
a) mass
a) mass
b) energy
c)
momentum
d) none
of the above
Ans: a
37.In
steady flow of a fluid, the total accele ration of any fluid particle
a) can be zero
a) can be zero
b) is
never zero
c)
is always zero
d) is
independent of coordinates
Ans: a
38. The pitot tube
is used to measure
a)
velocity at stagnation point
b) stagnation
pressure
c)
static pressure
d) dynamic
pressure
Ans: b
39. Hot wire
anemometer is used to measure
a)
discharge
b) velocity
of gas
c)
pressure intensity of gas
d) pressure
intensity of liquid
Ans: b
40.The
theoretical value of coefficient of contraction of a sharp edged orifice is
a) 0.611
a) 0.611
b) 0.85
c)
0.98
d) 1.00
Ans: a
Ans: a
41. Which of the
following is used to measure the discharge ?
a)
current meter
b) venturimeter
c)
pitot tube
d) hotwire
anemometer
Ans: b
42. Select the
incorrect statement.
a)
The pressure intensity at vena contracta is
atmospheric.
b) Contraction
is least at vena contracta.
c)
Stream lines are parallel throughout the jet at
vena contracta.
d) Coefficient
of contraction is always less than one.
Ans: c
43. Size of a
venturimeter is specified by
a)
pipe diameter
b) throat
diameter
c)
angle of diverging section
d) both
pipe diameter as well as throat diameter
Ans: a
44. Due to
each end contraction, the discharge of rectangular sharp crested weir is
reduced by
a) 5%
a) 5%
b) 10%
c)
15%
d) 20%
Ans: a
45. The discharge
through a V- notch varies as
a)
H1/2
b) H3'2
c)
H5/2
d) H5'4
where H is head.
Ans: c
46. Which of the
following is an incorrect statement ?
a)
Coefficient of contraction of a venturimeter is
unity.
b) Flow
nozzle is cheaper than venturimeter but has higher energy loss.
c)
Discharge is independent of orientation of
venturimeter whether it is horizontal, vertical or inclined.
d) None
of the above statement is correct.
Ans: d
47. Coefficient of
velocity of venturimeter
a)
is independent of Reynolds number
b) decreases
with higher Reynolds number
c)
is equal to the coefficient of discharge of
venturimeter
d) none
of the above
Ans: c
48. The pressure
at the summit of a syphon is
a)
equal to atmospheric
b) less
than atmospheric
c)
more than atmospheric
d) none
of the above
Ans: b
49. Ay between two
stream lines represents
a)
velocity
b) discharge
c)
head
d) pressure
Ans: b
50.Coefficient of velocity for Borda's mouth piece running full is
a) 0.611
a) 0.611
b) 0.707
c)
0.855
d) 1.00
Ans: b
51.Coefficient of discharge for a totally submerged orifice as compared to
that for an orifice discharging free is
a) slightly less
a) slightly less
b) slightly
more
c)
nearly half
d) equal
Ans: a
52. The major loss
of energy in long pipes is due to
a)
sudden enlargement
b) sudden
contraction
c)
gradual contraction or enlargement
d) friction
Ans: d
53.Coefficient of contraction for an external cylindrical mouthpiece is
a) 1.00
a) 1.00
b) 0.855
c)
0.7H
d) 0.611
Ans: a
54. Which of the
following has highest coefficient of discharge ?
a)
sharp edged orifice
b) venturimeter
c)
Borda's mouthpiece running full
d) CipoUetti
weir
Ans: b
55. In a Sutro
weir, the discharge is proportional to
a)
H1/2
b) H3/2
c)
H5/2
d) H
where H is head.
Ans: d
56. The
discharge over a broad crested weir is maximum when the depth of flow is
a) H/3
a) H/3
b) H/2
c)
2 H/5
d) 2
H/3 where H is the available head.
Ans: d
57. Which of the following statements is correct?
a)
Lower critical Reynolds number is of no
practical significance in pipe flow problems.
b) Upper
critical Reynolds number is significant in pipe flow problems.
c)
Lower critical Reynolds number has the value
2000 in pipe flow
d) Upper
critical Reynolds number is the number at which turbulent flow changes to
laminar flow.
Ans: a
Ans: a
58. For a sphere of radius 15 cm moving with a uniform
velocity of 2 m/sec through a liquid of specific gravity 0.9 and dynamic
viscosity 0.8 poise, the Reynolds number will be
a) 300
a) 300
b) 337.5
c)
600
d) 675
Ans: d
59. The
shear stress distribution for a fluid flowing in between the parallel plates,
both at rest, is a) constant over the
cross section
b) parabolic
distribution across the section
c)
zero at the mid plane and varies linearly with
distance from mid plane
d) zero
at plates and increases linearly to midpoint
Ans: c
60.If x is the
distance from leading edge, then the boundary layer thickness in laminar flow
varies as
a) x
a) x
b) x
c)
x
d) x/7
Ans: a
Ans: a
61. Stanton
diagram is a
a)
log-log plot of friction factor against Reynolds
number
b) log-log
plot of relative roughness against Reynolds number
c)
semi-log plot of friction factor against
Reynolds number
d) semi-log
plot of friction factor against relative roughness
Ans: a
Ans: a
62. The depth 'd'
below the free surface at which the point velocity is equal to the average
velocity of flow for a uniform laminar flow with a free surface, will be
a) 0.423 D
a) 0.423 D
b) 0.577
D
c)
0.223 D
d) 0.707
D where D is the depth of flow.
Ans: b
63.The boundary
layer thickness in turbulent flow varies as
a) x"7
a) x"7
b) x,/2
c)
x4/5
d) x3/5 where x is the distance from leading edge.
Ans: c
64. The distance y from pipe boundary, at which the
point velocity is equal to average velocity for turbulent flow, is
a) 0.223 R
a) 0.223 R
b) 0.423
R
c)
0.577 R
d) 0.707
R where R is radius of pipe.
Ans: a
65. If a sphere of diameter 1 cm falls in castor oil
of kinematic viscosity 10 stokes, with a terminal velocity of 1.5 cm/sec, the
coefficient of drag on the sphere is
a) less than 1
a) less than 1
b) between
1 and 100
c)
160
d) 200
Ans: c
66. In case of an airfoil, the separation of flow occurs
a)
at the extreme rear of body
b) at
the extreme front of body
c)
midway between rear and front of body
d) any
where between rear and front of body depending upon Reynolds number
Ans: a
Ans: a
67. When an ideal
fluid flows past a sphere,
a)
highest intensity of pressure occurs around the
circumference at right angles to flow
b) lowest
pressure intensity occurs at front stagnation point
c)
lowest pressure intensity occurs at rear
stagnation point
d) total
drag is zero
Ans: d
68. With the same
cross-sectional area and immersed in same turbulent flow, the largest total
drag will be on
a)
a circular disc of plate held normal to flow
b) a
sphere
c)
a cylinder
d) a
streamlined body
Ans: a
69. In which of
the following the friction drag is generally larger than pressure drag?
a)
a circular disc or plate held normal to flow
b) a
sphere
c)
a cylinder
d) an
airfoil
Ans: d
70. For
hydro-dynamically smooth boundary, the friction coefficient for turbulent flow
is
a) constant
a) constant
b) dependent
only on Reynolds number
c)
a function of Reynolds number and relative
roughness
d) dependent
on relative roughness only
Ans: b
71.The value of
friction factor 'f' for smooth pipes for Reynolds number 106 is approximately
equal to
a) 0.1
a) 0.1
b) 0.01
c)
0.001
d) 0.0001
Ans: b
72. For laminar flow in a pipe of circular cross-section,
the Darcy's friction factor f is
a)
directly proportional to Reynolds number and independent
of pipe wall roughness
b) directly
proportional to pipe wall roughness and independent of Reynolds number
c)
inversely proportional to Reynolds number and
indpendent of pipe wall roughness
d) inversely
proportional to Reynolds number and directly proportional to pipe wall
roughness
Ans: c
Ans: c
73. Separation of
flow occurs when
a)
the pressure intensity reaches a minimum
b) the
cross-section of a channel is reduced
c)
the boundary layer comes to rest
d) all
of the above
Ans: c
74. The ratio of
average velocity to maximum velocity for steady laminar flow in circular pipes
is
a) 1/2
a) 1/2
b) 2/3
c)
3/2
d) 2
Ans: a
75. The distance from pipe boundary, at which the turbulent
shear stress is one-third die wall shear stress, is
a)
1/3 R
b) 1/2
R
c)
2/3 R
d) 3/4R
where R is the radius of pipe.
Ans: a
76. The discharge of a liquid of kinematic viscosity
4 cm2/sec through a 8 cm dia-meter pipe is 3200n cm7sec. The type of flow
expected is
a) laminar flow
a) laminar flow
b) transition
flow
c)
turbulent flow
d) not
predictable from the given data
Ans: a
77. The Prartdtl
mixing length is
a)
zero at the pipe wall
b) maximum
at the pipe wall
c)
independent of shear stress
d) none
of the above
Ans: a
78. The velocity
distribution for laminar flow through a circular tube
a)
is constant over the cross-section
b) varies
linearly from zero at walls to maximum at centre
c)
varies parabolically with maximum at the centre
d) none
of the above
Ans: c
79. A fluid of kinematic viscosity 0.4 cm2/sec flows
through a 8 cm diameter pipe. The maximum velocity for laminar flow will be
a) less than 1 m/sec
a) less than 1 m/sec
b) 1
m/sec
c)
1.5 m/sec
d) 2
m/sec
Ans: b
80. The losses are
more in
a)
laminar flow
b) transition
flow
c)
turbulent flow
d) critical
flow
Ans: c
Ans: c
81. The wake
a)
always occurs before a separation point
b) always
occurs after a separation point
c)
is a region of high pressure intensity
d) none
of the above
Ans: b
82.The
maximum thickness of boundary layer in a pipe of radius r is
a) 0
a) 0
b) r/2
c)
r
d) 2r
Ans: c
83. The hydraulic grade line is
a)
always above the centre line of pipe
b) never
above the energy grade line
c)
always sloping downward in the direction of flow
d) all
of the above
Ans: b
84. Two pipe systems are said to be equivalent when
a)
head loss and discharge are same in two systems
b) length
of pipe and discharge are same in two systems
c)
friction factor and length are same in two
systems
d) length
and diameter are same in two systems
Ans: a
85. In series-pipe
problems
a)
the head loss is same through each pipe
b) the
discharge is same through each pipe
c)
a trial solution is not necessary
d) the
discharge through each pipe is added to obtain total discharge
Ans: b
86. Select the
correct statement.
a)
The absolute roughness of a pipe de-creases with
time.
b) A
pipe becomes smooth after using for long time.
c)
The
friction factor decreases
with time.
d) The
absolute roughness increases with time.
Ans: d
87. A valve is suddenly closed in a water main in wl.ich
the velocity is 1 m/sec and velocity of pressure wave is 981 m/ sec. The
inertia head at the valve will be
a) 1 m
a) 1 m
b) 10m
c)
100m
d) none
of the above
Ans: c
88. The
speed of a pressure wave through a pipe depends upon
a) the length of pipe
a) the length of pipe
b) the
viscosity of fluid
c)
the bulk modulus for the fluid
d) the
original head
Ans: c
89. When time of closure tc = L/v0 (where L is length
of pipe and v0 is speed of pressure wave), the portion of pipe length subjected
to maximum head is
a) L/4
a) L/4
b) L/3
c)
L/2
d) L
Ans: a
90. If the
elevation of hydraulic grade line at the junction of three pipes is above the
elevation of reservoirs B and C and below reservoir A, then the direction of
flow will be
a) from reservoir A to reservoirs B and C
a) from reservoir A to reservoirs B and C
b) from
reservoir B to reservoirs C and A
c)
from reservoir C to reservoirs A and B
d) unpredictable
Ans: c
91. The length of a pipe is 1 km and its diameter is
20 cm. If the diameter of an equivalent pipe is 40 cm, then its length is
a) 32 km
a) 32 km
b) 20
km
c)
8 km
d) 4
km
Ans: a
92. Two pipes of same length and diameters d and 2d
respectively are connected in series. The diameter of an equivalent pipe of
same length is
a)
less than d
b) between
d and 1.5 d
c) between
1.5 d and 2d
d) greater than 2d
Ans: a
93. The
horse power transmitted through a pipe is maximum when the ratio of loss of
head due to friction and total head supplied is
a) 1/3
a) 1/3
b) 1/4
c)
1/2
d) 2/3
Ans: a
94. The boundary
layer thickness at a distance of l m from the leading edge of a flat plate, kept
at zero angle of incidence to the flow direction, is O.l cm. The velocity
outside the boundary layer is 25 ml sec.
The boundary layer thickness at a distance of 4 m is
The boundary layer thickness at a distance of 4 m is
a) 0.40 cm
b) 0.20
cm
c)
0.10 cm
d) 0.05
cm
Assume that boundary
layer is entirely laminar.
Ans: b
95. Drag force is
a function of
i) projected area of the body
ii) mass density of the fluid
iii) velocity of the body
The correct answer is
a) (i) and (ii)
i) projected area of the body
ii) mass density of the fluid
iii) velocity of the body
The correct answer is
a) (i) and (ii)
b) (i)
and (iii)
c)
(ii) and (iii)
d) (i),
(ii) and (iii)
Ans: d
96. The
correct relationship among displacement thickness d, momentum thickness m and
energy thickness e is
a) d > m > e
a) d > m > e
b) d
> e > m
c)
e > m > d
d) e
> d > m
Ans: d
97.For
laminar flow in circular pipes, the Darcy's friction factor f is equal to
a) 16/Re
a) 16/Re
b) 32/
Re
c)
64/ Re
d) none
of the above where R,, is Reynolds number.
Ans: c
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