Momentum Transfer (Set 1) Flashcards
As one of the transport phenomena, the concepts in momentum transfer (also known as fluid mechanics) are crucial for the design, operation, and maintenance of fluid flow equipment such as pipes, pumps/compressors, turbines/expanders, agitators, and metering devices.
1
Q
The fluid property, due to which, mercury does not wet the glass is
A
surface tension
2
Q
Laminar flow of a Newtonion fluid ceases to exist, when the Reynolds number exceeds
A
2100
3
Q
When the momentum of one fluid is used for moving another fluid, such a device is called a/an
A
jet pump
4
Q
The head loss in turbulent flow in a pipe varies
A
as (velocity)^2
5
Q
Most commonly used joint in the underground pipe lines is the
A
sleevejoint
6
Q
Schedule number of a pipe, which is a measure of its wall thickness, is given by
A
1000 P’/S
7
Q
The net positive suction head (NPSH) of a centrifugal pump is defined as the sum of the velocity head and the pressure head at the
A
suction minus vapor pressure of the liquid at suction temperature.
8
Q
With increasing flow rate, the hydraulic efficiency of a centrifugal pump
A
monotonically decreases.
9
Q
The velocity profile for turbulent flow through a closed conduit is
A
logarithmic
10
Q
In case of hydraulically smooth pipe, the resistance to flow depends only on the Reynolds number, whereas for a hydraulically rough pipe, the resistance to flow is governed by the relative roughness. Two pipes are said to have the same hydraulic roughness, when they have equal values of
A
friction co-efficient for flows at equal Reynold number.
11
Q
Water hammer in a pipeline results from the
A
rapid pressure change due to a rapid change in the rate of flow.
12
Q
Molten soap mass is transported by a ____ pump.
A
centrifugal
13
Q
Which of the following denotes the effect of compressibility in fluid flow ?
A
Mach number
14
Q
Nominal size of the discharge pipe of a pump is usually ____ the nominal size of the inlet pipe.
A
smaller than
15
Q
The terminal velocity of a small sphere settling in a viscous fluid varies as the
A
inverse of the fluid viscosity.
16
Q
If the discharge of a centrifugal pump is throttled, then its suction lift
A
increases
17
Q
Foot valves provided in pumps are ____ valves.
A
directional control
18
Q
At high Reynolds number
A
inertial forces control and viscous forces are unimportant.
19
Q
Power loss in an orificemeter is ____ that in a venturimeter.
A
more than
20
Q
The terminal velocity of a particle moving through a fluid varies as dpn. What is the value of n’ for Newton’s law regime ?
A
0.5
21
Q
What is the normal range of exit cone angle of a venturimeter ?
A
7 to 15
22
Q
The dimension of dynamic viscosity is
A
ML^-1T^-1
23
Q
A particle A of diameter 10 microns settles in an oil of specific gravity 0.9 and viscosity 10 poise under Stoke’s law. A particle B with diameter 20 microns settling in the same oil will have a settling velocity
A
one fourth as that of A.
24
Q
The pitot static tube does not measure the ____ pressure.
a. static
b. total
c. difference in static & dynamic
A
all of these
25
The fluid in which the shearing stress within it is proportional to the velocity gradient across the sheared section, is called a ____ fluid.
Newtonion
26
The ratio of the depth of flow to the hydraulic radius for the most economical trapezoidal section, in open channel flow is
2
27
The drag co-efficient for a bacterium moving in water at 1 mm/s, will be of the following order of magnitude (assume size of the bacterium to be 1 micron and kinematic viscosity of water to be 10^-6m^2/s).
0.44
28
For Laminar flow through a packed bed, the pressure drop is proportional to (Vs is the superficial liquid velocity and Dp is the particle diameter)
Vs/Dp^2
29
The maximum delivery pressure of compressors can be upto ____ atmospheres.
1000
30
Dimension of surface tension is(where, F = force, L = length)
FL^-1
31
Which of the following is not a dimension-less parameter ?
None of these
32
Co-efficient of velocity is ____ the coefficient of discharge.
more than
33
All pipes of a particular nominal size have the same
outside diameter
34
For the transfer of solution of thick slurry, the pump used is a ____ pump.
diaphragm
35
Which of the following is not concerned with the fluid-particle interaction ?
Weber number
36
Maximum theoretical suction lift for water at 15°C by a centrifugal pump is 34 ft. The same for water at 90°C will be ____ ft.
8
37
Pressure drag does not depend upon the
a. roughness of surface of the body.
b. pressure of main flow only.
c. length of the body in flow direction.
all of these
38
Dimension of absolute viscosity is
ML^-1T^-1
39
____ pumps are axial flow pumps.
Propeller
40
Brownian movement is prominent in the particle size range of ____ microns in case of settling of a particle in a fluid.
2 to 3
41
For a particle settling in water at its terminal settling velocity, which of the following is true ?
Weight = buoyancy + drag
42
A Bingham fluid of viscosity μ = 10 Pa.s and yield stress, τ0 = 10 KPa, is shared between flat parallel plates separated by a distance of 10-3 m. The top plate is moving with a velocity of 1 m/s. The shear stress on the plate is
20 KPa
43
Pick out the correct statement.
A forced vortex occurs when fluid rotates as a solid about an axis.
44
Shear stress in a fluid flowing in a round pipe
is zero at the centre and varies linearly with the radius.
45
The resistance wire used in a hot wire anemometer for conducting electrical current is made of
tungsten
46
Two dimensional stream function
is constant along a stream line.
47
What causes cavitation in centrifugal pump ?
Low suction pressure
48
Draining of shallow pits or sump is done by a sump pump, which is a ____ pump.
single stage vertical
49
A hydraulic ram acts as a/an ____ pump.
impulse
50
The ratio of average fluid velocity to the maximum velocity in case of laminar flow of a Newtonion fluid in a circular pipe is
0.5
51
Choose the correct set of dimensions of viscosity that are equivalent (where, F, M, L, T are dimensions for force, mass, length and time respectively).
FL^-2T, ML^-1T^-1
52
The line of action of the buoyant force passes through the centre of gravity of the
displaced volume of the fluid.
53
Pick out the wrong statement.
With increase in the Mach number >0.6, the drag co-efficient decreases in case of compressible fluids.
54
The friction factor for turbulent flow in a hydraulically smooth pipe
depends only on Reynolds number.
55
The pressure at a point in a fluid is not the same in all directions, when the fluid is viscous and
moving
56
What causes convective acceleration in fluid flow ?
Non-uniformity of flow
57
The Stoke's stream function applies to the
cases of axial symmetry.
58
Slugging in a fluidised bed can be avoided by using
shallow beds of solids and proper choice of particle size.
59
The ratio of width to depth for the most economical rectangular section in open channel flow is
2
60
The simple pitot tube measures the ____ pressure.
total
61
Capacity of a hydraulic accumulator is defined in terms of maximum
amount of energy stored.
62
Three piping networks as shown in the figure are placed horizontally. They are made using identical pipe segments and are subjected to the same pressure drop across them. Assuming no pressure losses at junctions, the flow rates across the three networks are related as Q1 : Q2 : Q3. (1)
0.043078704
63
Boundary layer separation is characterised by one of the conditions given below, where 'Re' is the Reynolds number for the flow. Select the appropriate conditions.
Re `>>` 1, decelerating flow
64
Manometers measure the ____ pressure.
difference in
65
Which of the following fluid forces are not considered in the Navier-Stoke's equation?
Turbulent forces
66
Which of the following may be termed as a variable orifice flowmeter ?
Rotameter
67
In turbulent flow, a rough pipe has the same friction factor as a smooth pipe
when the roughness projections are much smaller than the thickness of the laminar film.
68
Air vessel provided in a reciprocating pump
a. smoothens the flow by avoiding pulsations.
b. increases the volumetric efficiency of the pump.
c. saves the pump from the danger of cavitation.
none of these.
69
Bernoulli's equation is dependent on the
none of these.
70
The capacity of an accumulator is the maximum
energy which it can store.
71
With increase in the temperature, viscosity of a liquid
decreases
72
Vena-contracta pressure tapping is at a distance ____ from the position of an orificemeter fitted in a pipe of internal diameter 'd'
0.5 d
73
The pump impeller and the turbine runner in a hydraulic torque converter
have different diameters.
74
Reciprocating pumps compared to centrifugal pumps
are not subject to air binding.
75
The fluid property which matters for fall-ing rain drops to acquire spherical shape is its
surface tension
76
The simple pitot tube does not measure the
a. static pressure.
b. dynamic pressure.
c. velocity at the stagnation point.
all of these
77
Boundary layer separation occurs when the
cross-section of the channel is reduced.
78
The head loss in turbulent flow in a pipe varies
approximately as the square of the velocity.
79
For flow through an orifice from a reservoir, the actual velocity at the vena con-tracta is given by
C.V. √2gh
80
The ratio of the hydraulic radius to the diameter of the channel, for maximum mean velocity of flow in a circular channel, in open channel flow is
0.3
81
For the free settling of a spherical particle through a fluid, the slope of, CD-log NRe , plot is
-1
82
A centrifugal pump loses prime after starting. The reason of this trouble may be
a. incomplete priming.
b. too high a suction lift.
c. low available NPSH and air leaks in the suction pipe.
all of these
83
Venturimeter and orificemeter measures the ____ of the fluid.
average velocity
84
Surge tanks are provided in high pressure water pipelines to
reduce the water hammer.
85
Working principle of manometer comprises of balancing a coloumn of liquid against the pressure to be measured. Inclined tube manometer is especially used for the measurement of ____ pressure.
small differential
86
Isotropic turbulence occurs
where there is no velocity gradient.
87
The co-efficient of drag and lift for an incompressible fluid depends on the
Reynolds number
88
Euler's equation of motion states, that at every point, the
force per unit mass equals acceleration.
89
Hydraulic intensifier is used for increasing the
intensity of pressure of the liquid.
90
Which of the following is the 'Blaussius equation', relating friction factor to the Reynolds number ?
f = 0.079.Nre^-0.25
91
Hydrometer measures the specific gravity of liquids based on the principles of buoyancy. Pycnometer is used to measure the specific gravity of
a. powder & grannular solids
b. liquids
c. low melting point semi-solids
all of these
92
Euler's equation of motion is a statement expressing
conservation of mass.
93
During ageing of fluid carrying pipes, the
absolute roughness increases linearly with time.
94
Pick out the wrong statement.
An ideal fluid is the one, which has negligible surface tension and obeys the Newton's law of viscosity.
95
Mass velocity is independent of temperature & pressure, when the flow is
steady and the cross-section is unchanged.
96
Very small pressure difference (< 5 mm water coloumn) can be most conveniently measured by a/an ____ manometer.
inclined tube water.
97
For pipe flows, head is proportional to ____ at constant capacity(where, D = pipe diameter).
1/D^5
98
The energy equation, (1) (E = internal energy/mass), is applicable to
all compressible fluids.
99
A differential pressure cell is used for
remote recording of pressure difference.
100
If more than two branches of pipes are to be connected at the same point, then use a/an
tee
101
In case of a centrifugal pump, the ratio of total delivered pressure to pressure developed with the impeller is called the ____ efficiency.
manometric
102
Acceleration head in a reciprocating pump
does not change the work requirement of the pump.
103
The ratio of inertial forces to elastic forces is called the ____ number.
Mach
104
Fluid flow at increasing rate through a diverging pipe is an example of ____ flow.
non-steady non-uniform
105
The temperature in isentropic flow
depends on Mach number only.
106
A fluid element has a velocity V = -y^2 . xi + 2yx^2 . j. The motion at (x, y) = (l/√2, 1) is
rotational and compressible
107
Check in a centrifugal pump is
a. provided in the discharge line.
b. generally a globe valve.
c. provided to prevent liquid from backing up through the pump when the pump is turned off or accidently stops running.
all of these
108
Drag force acting on a body does not depend upon the
density of the body.
109
Centrifugal pump is normally classified on the basis of the
type of casing.
110
Where does the maximum stress occur in case of laminar flow of incompressible fluid in a closed conduit of diameter 'd'?
At the wall
111
In case of isentropic flow, the speed of sound in an ideal gas is proportional to (where, T = absolute temperature )
√T
112
Applying a pressure drop across a capillary results in a volumetric flow rate 'Q' under laminar flow conditions. The flow rate for the same pressure drop, in a capillary of the same length but half the radius is
Q/16
113
Cd, Cc and Cv are related (for flow through an orifice) as (where, Cd = discharge co-efficient Cc = co-efficient of contraction (1) Cv = co-efficient of velocity (2)
Cd = Cc.Cv
114
In an incompressible fluid, the density is
not affected with moderate change in temperature & pressure.
115
Check valves are used
for unidirectional flow.
116
Velocity distribution for flow between two fixed parallel plates
varies parabolically across the section.
117
Priming is needed in a ____ pump.
centrifugal
118
Which of the fluid forces are not considered in the Reynold's equation of flow ?
Compressibility forces
119
For ideally incompressible fluid, the Mach number will be
1
120
A mono pump is a ____ pump.
positive acting rotary
121
Higher specific speed (200-500) of a centrifugal pump indicates that the pump is of ____ flow type.
axial
122
The variable required to be known in correlations used for estimating the horse power of a centrifugal gas compressor and hence its cost are P. Inlet pressure Q. Compressor rpm R. Delivery pressure S. Volumetric flow rate at inlet.
P, Q and R
123
Theoretical head developed by a centrifugal pump does not depend upon the ____ the impeller.
a. radius of
b. speed of
c. fluid velocity leaving
none of these
124
In case of isentropic flow, the speed of sound in an ideal gas is proportional to (where M = molecular weight of the gas)
1/√M
125
Boundary layer separation is caused by the
adverse pressure gradient.
126
With increase in temperature, the vapor pressure of liquids
increases
127
A mercury (specific gravity = 13.6) manometer connected across an orificemeter fitted in a pipe shows a manometer reading of 2 cms. If the manometer liquid is changed to carbon tetrachloride (specific gravity = 1.6), then for the same flow rate of water the new manometer reading will be ____ cms.
17
128
The ratio of wall drag to total drag in the Stoke's law range is
2/3
129
Rotary vacuum pumps can reduce the absolute pressure to as low as ____ mm Hg.
0.01
130
A pitched-blade turbine draws ____ a straight blade turbine.
less power than
131
The most suitable flow measuring device for the fluid flow measurement in a very large diameter pipeline is a
pitot tube
132
A centrifugal pump is called a turbine pump, if it is having a
vaned diffusion casing.
133
Remote control valve is a ____ valve.
butterfly
134
Which of the following quantities are computed by using the hydraulic radius for non-circular ducts ?
Reynold number, relative roughness and head loss.
135
Centre of pressure in an immersed body is ____ the centre of gravity.
below
136
The centre of pressure is
a point on the line of action of the resultant force.
137
Pascal law is not applicable for a/an ____ fluid.
a. accelerating frictionless
b. static
c. uniformly moving
none of these
138
In a fluidised bed reactor
temperature is more or less uniform.
139
The flow of a liquid through tapering pipe at a constant rate is an example of ____ flow.
steady non uniform
140
Pick out the correct statement pertaining to transition/ entrance length in fluid flow.
a. The length of entrance region of pipe, in which full development of fluid flow takes place such that velocity profile does not change downstream, is called the transition length.
b. Transition length for laminar flow of Newtonion fluids in a pipe of diameter 'd' is equal to 0.05. D.NRe.
c. Transition length for turbulent flow of Newtonion fluids in a smooth pipe of diameter 'd' is equal to 50 D.
all of these
141
A perfect gas
has constant specific heat.
142
In a/an ____ , the flow rate of fluids is obtained by measuring the difference between the impact and the static pressure.
pitot tube
143
During fluid flow, variation of shear stress(τ) with velocity gradientat (dv/dy) constant pressure temperature is shown below in the figure In the above figure, Binghom plastic is represented by the curve .
II
144
Speed of sound in an ideal gas depends on its
temperature
145
A centrifugal pump designed for handling water (μ = 1 cp) will deliver ____ when pumping a thicker oil (μ = 30 cp).
less head & capacity
146
If 'x' is the depth of flow in an open channel of large width, then the hydraulic radius is equal to
x
147
In fluid flow, the boundary layer separation can not occur
none of these.
148
For a given fluid flow rate, which of the following incurs maximum head loss ?
Orifice meter
149
Which of the following assumptions enables the Euler's equation of motion to be integrated ?
The fluid is incompressible.
150
A fluid whose apparent viscosity increases with shear rate is termed as the ____ fluid.
dilatant
151
Which of the following is the most common pump for pumping either raw sewage or sludge ?
Reciprocating pump
152
Transition length for a turbulent fluid entering into a pipe is around ____ times the pipe diameter.
50
153
For turbulent flow of an incompressible fluid through a pipe, the flow rate Q is proportional to (Δ P)n, where ΔP is the pressure drop. The value of exponent 'n' is
< 1
154
Reciprocating pumps are not able to compete with the centrifugal pump for industrial use, mainly because these pumps have
higher capital &maintenance cost.
155
Which is the correct relationship for a centrifugal pump ? (where, D = Impeller diameter, inches H = Head developed, ft of liquid pumped N = Speed of pump, rpm)
D = 1840 H^0.5/N
156
Which of the following pipe bends will incur the largest head loss ?
U-bend
157
Which is the most efficient and best for measuring very small flow rate of gases ?
Rotameter
158
When the water is warm, the height to which it can be lifted by a pump
decreases due to reduced vapour pressure.
159
Pipes having diameter 14 inches or more are designated by their
outside diameter
160
Viscosity of water at 40°C lies in the range of
0.5 x 10^-3 to 1 x 10^-3 kg/m.s
161
A centrifugal pump has the following specifications: Power = 4 H.P.; Speed = 800 rpmHead = 8 metresFlow = 1000 litres/minutes.If its speed is halved, the new discharge will be ____ litres/minute.
500
162
The dimension of kinematic viscosity is
L^2T^-1
163
A pipe of I.D. 4 m is bifurcated into two pipes of I.D. 2 m each. If the average velocity of water flowing through the main pipe is 5 m/sec, the average velocity through the bifurcated pipes is
10 m/sec
164
Turbulent flow generally occurs for cases involving
none of these
165
Lower BWG means ____ of the tube.
lower cross-section
166
For laminar flow of Newtonion fluid in a circular pipe, the velocity distribution is a function of the distance 'd' measured from the centre line of the pipe, and it follows a ____ relationship.
parabolic
167
The Prandtl mixing length is
useful for computing laminar flow problems.
168
N^2Re/NFr is called the ____ number.
Galileo
169
The location of centre of pressure, which defines the point of application of the total pressure force on the surface, can be calculated by applying the principle of moments according to which "sum of the moment of the resultant force about an axis is equal to the sum of the components about the same axis". The centre of pressure of a rectangular surface (of width 'w') immersed vertically in a static mass of fluid is at a depth of(where, y = depth of the liquid)
2y/3
170
As the velocity V and thus the Reynolds number of a flow past a sphere increases from very low value, the drag force for Re << 1
increases linearly with V.
171
Self-priming centrifugal pump can be used for
all of these
172
Water hammer is caused, when water flowing in a pipe is suddenly brought to rest by closing the valve. The extent of pressure thus produced due to water hammer depends on the
all of these
## Footnote
pipe length, fluid velocity in the pipe, time taken to close the valve
173
Bernoull's equation does not apply to the functioning of a/an
none of these
174
What is the shear rate at the pipe wall, in case of laminar flow of Newtonion fluids in a pipe of diameter 'D' & length 'L' incurring a pressure drop 'Δp' with average velocity 'Vavg'?
8 . Vavg/D
175
Pascal's law is valid, only when the fluid is
at rest.
176
A centrifugal pump is used to pump water through a horizontal distance of 150 m, and then raised to an overhead tank 10 m above. The pipe is smooth with an I.D of 50 mm. What head (m of water) must the pump generate at its exit (E) to deliver water at a flow rate of 0.001 m^3/s? The Fanning friction factor, f is 0.0062.
11 m
177
The pressure head of a flow meter remains constant for
rotameter
178
A venturimeter can not be used for the direct measurement of
all of these
179
A double acting reciprocating pump compared to a single acting pump (of almost same size working under same pressure levels) would give almost double
discharge
180
Which of the following is used for very accurate measurement of flow of gas at low velocity ?
Hot wire annemometer
181
In Newton's law range, the drag co-efficient for the motion of spherical particle in a stationary fluid is
0.44
182
A pressure of 10 m head of water is equivalent to ____ kN/m2.
98
183
A pressure head of 320 metres of water in meters of CCl4 (sp.gr = 1.6) will be
200
184
The ratio of the wall drag to the form drag in the Stoke's law range (for motion of spherical particles in a stationary fluid) is
2
185
For turbulent flow in smooth circular pipe, the velocity distribution is a function of the distance 'd' measured from the wall of the pipe and the friction velocity 'v', and it follows a ____ relationship.
logarithmic
186
Maintenance cost of a ____ pump for a particular duty is the least.
centrifugal
187
Choking in case of pipe flow means that a
specified mass flow rate can not be achieved.
188
Velocity of liquid hydrocarbon fuels in a pipeline can not be measured by magnetic flowmeters, because their ____ is very low/small.
electrical conductivity
189
The nominal size of a hose pipe is specified by its
I.D.
190
Transition from laminar flow to turbulent flow is aided by the
all of these.
191
For flow of fluids through packed bed, the superficial velocity is
less than the average velocity through channels.
192
Cd is always ____ Cc.
greater than
193
Buoyant force
depends on the weight of the floating body.
194
Which of the following is an undesirable property of a manometric liquid ?
High vapour pressure.
195
Characteristic curves for a centrifugal pump plotted against its capacity is shown in the diagram. x, y and z denote respectively (1)
head, efficiency and B.H.P.
196
Liquid delivery by centrifugal pump starts, only when the head developed by it is equal to the ____ head.
manometric
197
The speed of sound in an ideal gas varies as the
temperature
198
The maximum head that can be developed by a single impeller is ____ ft.
250-300
199
The ratio of hydrodynamic boundary layer to thermal boundary layer thickness in case of liquid metals is
< 1
200
The general relationship between speed N, head H, power P and discharge Q for a centrifugal pump is
Q∝N : H∝N^2 : P∝N^3
201
What is the ratio of the velocity at the axis of the pipe to the mean velocity of flow in case of pipe flow under viscous condition ?
2
202
Foot valve provided in the pump is a ____ valve.
back pressure
203
The discharge co-efficient for an orificemeter does not depend upon the
pipe length.
204
Which of the following options will facilitate the achievement of a very high head (say 30 metres) in case of a centrifugal pump?
Mounting of two or more impellers in series on a single shaft.
205
An equipotential line is ____ to the velocity vector at every point.
normal
206
Path followed by water jet issuing from the bottom of a water tank will be a
parabola (vertex being at the opening).
207
Which of the following produces maximum pressure difference for transportation of gases ?
Compressors
208
For flow through a venturi at a particular discharge, the correct relationships among velocities at point X, Y and Z would be (1)
V2 > V1 and V2 > V3
209
Drag co-efficient in hindered settling is ____ that in free settling.
always greater than
210
Efficiency of power transmission (η) through a circular pipe is given by (ht - hf)/ht, which has a maximum value of ____ percent.
66.6
211
One dimensional fluid flow implies the
flow in which transverse components are zero.
212
____ forces act on a particle moving through a stationary fluid.
all of these
213
In frictional fluid flow, the quantity, (1) , is
not constant along a streamline.
214
Hydraulic radius is the ratio of
flow area to wetted perimeter.
215
The unit of bulk modulus of elasticity for a liquid in S.I. unit is
N/m^2
216
Power requirement of fans having constant wheel diameter varies ____ fan speed.
as cube of
217
In the low Reynolds number region, the drag force on a sphere is proportional to
V
218
The continuity equation
represents the conservation of mass.
219
Experimental study of laminar fluid flow through a circular tube was conducted by
Hagen and Poiseuille
220
The most economical flow control valve for use with large diameter pipes is a
butterfly valve
221
Each term in Bernaulli's equation represents the ____ of the fluid.
energy per unit weight
222
Which of the following is a dimensionless parameter ?
None of these
223
If the head over the triangular notch is doubled, the discharge will increase by ____ times.
5.657
224
Friction factor for a hydraulically smooth pipe at NRe = 2100 is f1. If the pipe is further smoothened (i.e., roughness is reduced), the friction factor at the same value of NRe, will
increase.
225
For the laminar flow of a fluid in a circular pipe of radius R, the Hagen-Poisseule equation predicts the volumetric flow rate to be proportional to
R^4
226
Interstage coolers are provided in a multistage compressor to
save power in compressing a given volume to a given pressure.
227
Consider a centrifugal pump having a specific impeller diameter, fixed impeller speed pumping a liquid of constant density at a particular discharge capacity. With decrease in the capacity of the pump, the ____ decreases.
all of these
228
Reynolds number is the ratio of
inertial forces to viscous forces.
229
For the manometer set up shown in the figure, the pressure difference PA - PB is given by (1)
(ρH - ρair)gH
230
The discharge through a venturimeter depends upon
pressure drop only.
231
N. second/m^2 is
the S.I. unit of dynamic viscosity.
232
The distance between metacentre and ____ is called metacentric height.
centre of gravity
233
Check valve is used for ____ flow.
unidirectional
234
Capacity of a rotary gear pump can be varied by
all (a), (6) and (c).
235
For a given Reynolds number, in a hydraulically smooth pipe, further smoothening ____ the friction factor.
brings about no further reduction of
236
Power number is the ratio of
drag stress to inertial stress.
237
The momentum correction factor for the velocity distribution of laminar flow is
none of these
238
For the same flow rate of a fluid, the pressure drop is the least for
venturimeter
239
The valve commonly used in pipes larger than 2" dia is a
gate valve
240
Foot valves are provided in the suction line of a centrifugal pump to
avoid priming, every time we start the pump.
241
An ideal fluid is
frictionless & incompressible.
242
In area meter (e.g., rotameter), with increase in the fluid flow rate, the
pressure drop is almost constant.
243
In power law, (1) , then the fluid is
Newtonian
244
The buoyant force acting on a floating body is dependent on the
weight of the liquid displaced.
245
A Newtonion fluid is that
for which shear & deformation are related as (1)
246
In case of end to end connection of two or more pipes in series, the ____ each pipe.
same rate of flow passes through
247
Which of the following equations applies to the fluid flow through a packed bed for very large Reynolds number ?
Blake-Pllummer equation
248
The flow of gas along a pipe in the direction of decreasing pressure causes decrease in its
specific volume
249
Centrifugal pump can't be used to pump
thick molten soap at 80°C.
250
A stream line is
fixed in space in steady flow.
251
Quicksand is an example of a ____ fluid.
dilatent
252
Correction for capillary effect in manometers (used for pressure measurement) need not be applied, if diameter of the manometer tube is ____ mm.
> 12.5
253
Differential manometer measures the
pressure difference
254
The pressure and power requirement of a gas fan at constant speed & capacity varies ____ the gas density.
directly as
255
Boundary layer thickness in laminar flow over a flat plate increases as(where, d = distance from the leading edge.)
√d
256
Gradually varied flow in open channel is a/an ____ flow.
steady non-uniform
257
The line of action of the buoyant force acts through the
centroid of the displaced volume of fluid.
258
Cavitation in a centrifugal pump can be avoided by keeping the
inlet pressure high
259
Vane anemometer
rotates an element at a speed determined by the velocity of the fluid in which the meter is immersed.
260
The peripherial velocity at inlet of a centrifugal pump having inlet diameter of 25 cms and rotating at 950 rpm is ____ m/sec.
12.4
261
Laminar flow is characterised by the nonexistence of
all (a), (b)&(c).
262
The length of the tube necessary for the boundary layer to reach the centre of the tube and for fully developed flow to be established is called the ____ length.
transition
263
Select the correct practical example of steady non-uniform flow.
Steadily decreasing flow through a reducing section.
264
Hydraulic diameter for non-circular ducts is equal to ____ times the area of flow divided by the perimeter.
four
265
Terminal velocity is
a constant velocity with no acceleration.
266
Consider two pipes of same length and diameter through which water is passed at the same velocity. The friction factor for rough pipe is f1 and that for smooth pipe is f2. Pick out the correct statement.
f1 > f2
267
For an incompressible fluid, the bulk modulus of elasticity is
∞ N/m^2
268
A fluid is a substance, that
flows when even a small shear is applied to it.
269
The pressure intensity is the same in all directions at a point in a fluid
when there is no motion of one fluid layer relative to an adjacent layer.
270
Which of the following must be followed by the flow of a fluid (real or ideal)? (I) Newton's law of viscosity. (II) Newton's second law of motion. (III) The continuity equation. (IV) Velocity of boundary layer must be zero relative to boundary. (V) Fluid cannot penetrate a boundary.
II, III, V
271
Mach number is defined as the ratio of the local flow velocity to the sonic velocity in the fluid. For what value of Mach number, the gases are considered incompressible ?
< 0.3
272
Boundary layer exists in flow
of real fluids.
273
Rubber latex is an example of ____ fluid.
pseudoplastic
274
The frictional resistance in laminar flow does not depend on the
area of surface in contact.
275
A venturimeter measures the
none of these
276
Gradually varying fluid flow is an example of ____ flow.
non-steady uniform
277
Drag is the force component exerted on an immersed object,
the component being parallel to theflow direction.
278
To handle smaller quantity of fluid at higher discharge pressure, use a ____ pump.
reciprocating
279
Cocks are used to control
any liquid
280
The dimension of surface tension is
MT^-2
281
Pick out the correct statement.
Mach number is given by the ratio of the speed of the fluid to that of sound in the fluid under conditions of flow.
282
The friction factor is
none of these.
283
Rubber latex is an example of a ____ .fluid.
pseudoplastic
284
Which of the following factors does not contribute to the pressure drop in a pipeline ?
None of these
285
The phenomenon occuring during pumping of a liquid solution containing dissolved gases, which may come out of the solution giving rise to gas pockets, is termed as
cavitation
286
Working of a ____ pump characterises mixed flow.
turbine
287
The rate of change of moment of momentum represents the ____ by the fluid.
torque applied
288
Cd for the orifice plate varies from
0.58 to 0.8
289
The discharge through a V-notch weir varies as
H^5/2
290
Water flow rate in a pipe of 3.5 metres diameter can be most economically and conveniently measured by a/an
pitot tube
291
The specific speed of a pump is defined as the speed of a unit of such a size, that it
delivers unit discharge at unit head.
292
In case of venturimeters, friction losses are about ____ percent of maximum velocity head.
2
293
With increase in the schedule number of a pipe of a particular nominal size, the
all of these
294
Turbine impeller
is effective over wide range of viscosities.
295
Friction produced by the formation of wakes is called the ____ friction.
form
296
Various efficiencies of a centrifugal pump are related as (where, ηm = mechanical efficiency ηv = volumetric efficiency. ηma = manometric efficiency ηo = overall efficiency)
ηm = ηv . ηma
297
When the pipe Reynold's number is 6000, the flow is generally
turbulent
298
With a constant diameter impeller of a centrifugal pump
head varies as the square of speed.
299
For water, when the pressure increases, the viscosity
first decreases, and then increases
300
Location of vena-contracta in an orificemeter does not depend upon the
type of orifice.
301
At low Reynolds number
viscous forces control and inertial forces are unimportant.
302
For laminar flow through a closed conduit
Vmax = 2Vav
303
In Newton's law range, the terminal velocity of a solid spherical particle falling through a stationary fluid mass varies as the ____ of its diameter.
square root
304
Unsteady uniform flow is represented by flow through a/an
long pipe at decreasing rate.
305
If Blausius or Darcey friction factor is 'f1' then the Fanning friction factor is equal to
f1/4
306
Pick out the wrong statement pertaining to fluid flow.
The ratio of average velocity to the maximum velocity for turbulent flow of Newtonion fluid in circular pipes is 0.5.
307
A Newtonion liquid (ρ = density, μ = viscosity) is flowing with velocity v in a tube of diameter 'D'. Let Δp be the pressure drop across the length 'L'. For a laminar flow, Δp is proportional to
L ρv2/D
308
While starting a centrifugal pump, its delivery valve should be kept
closed.
309
For flow past a flat plate, if x is the distance along the plate in the direction of flow, the boundary layer thickness is proportional to
x
310
Sewage sludge is an example of the ____ fluid.
Bingham plastic
311
Multistage centrifugal pumps are generally used for
high head.
312
The fluid jet discharging from a 2" diameter orifice has a diameter of 1.75" at its vena-contracta. The co-efficient of contraction is
0.766
313
A bed consists of particles of density 2000 kg/m^3. If the height of the bed is 1.5 metres and its porosity 0.6, the pressure drop required to fluidise the bed by air is
11.77 kPa
314
Cavitation in a pump creates so many undesirable effects. Out of the following, which is not an undesirable effect created by cavitation ?
Develops high pressure
315
For a specific centrifugal air blower operating at constant speed & capacity, the power requirement and pressure vary
directly as gas density.
316
Capillary tube method of viscosity measurement is based on the
Hagen-Poiseulle's equation
317
It is possible to integrate an automatic flow controller to a
rotameter
318
For liquid flow through a packed bed, the superficial velocity as compared to average velocity through the channel in the bed is
less
319
For a reciprocating pump, the indicator diagram is the graph between the
volume swept by piston for one complete revolution and the pressure in the cylinder.
320
High specific speed of a pump implies that, it is a/an ____ pump.
axial flow
321
A gas (density = 1.5 kg/m^3 , viscosity = 2x 10^-5 kg/m.s) flowing through a packed bed (particle size = 0.5 cm, porosity = 0.5) at a superficial velocity of 2 m/s causes a pressure drop of 8400 Pa/m. The pressure drop for another gas, with density of 1.5kg/m^3and viscosity of 3 x 10^-5kg/m.s flowing at 3 m/s will be
12600 Pa/m
322
One poise (unit of absolute/dynamic viscosity) is equivalent to one
gm/cm. sec.
323
The equation relating friction factor to Reynold number, f^-0.5 = 4 loge (NRe/f)^-0.4, is called the ____ equation.
Nikuradse
324
What is the co-efficient of contraction, if a fluid jet discharging from a 50 mm diameter orifice has a 40 mm diameter at its vena-contracta ?
0.64
325
For an unstable equilibrium of a floating body (where, M = metacentre.)
M is below G
326
Which of the following can be used for the direct measurement of volumetric flow rate of slurry ?
Rotameter
327
A pipe is defined as 'hydraulically smooth', if the friction factor
for a given Reynolds number remains constant even on further smoothening of the pipe.
328
A Pitot tube indicates 5 cm of water (manometer) when it is being used for measuring velocity of air. The velocity of air in m/sec is
28.2
329
Delivery of insufficient quantity of liquid by a pump may be caused by
all of these
330
In case of a ____ the energy of flow is considerably decreased downstream of the machine.
turbine
331
With increase in the shear rate, the apparent viscosity of pseudoplastic fluids
decreases
332
Co-efficient of discharge (Cd) is defined as actual discharge/theoretical discharge and is equal to Cc . Cv; where Cc = Co-efficient of contraction and Cv = co-efficient of velocity. Cd of an orifice is usually about
0.62
333
Purpose of hydraulic accumulator is to
generate high pressure to operate hydraulic machines like cranes, lifts, presses etc
334
Pick out the wrong statement.
In case of unsteady fluid flow, the velocity at any given point does not change with time.
335
Purpose of relief valve in a reciprocating pump is to
protect the pump against developing excessive pressure.
336
Select the correct statement.
The discharge through a venturimeter depends upon Δp only and is independent of orientation of the meter.
337
In case of turbulent flow of fluid through a circular pipe, the
skin friction drag, shear stresses, random orientation of fluid particles and slope of velocity profile at the wall are more.
338
What is the maximum theoretical suction lift (metres) of a reciprocating pump ?
10
339
The terminal velocity of a particle moving through a fluid varies as dp^n. The value of n is equal to ____ in Stoke's law regime.
2
340
Function of air vessel provided in a reciprocating pump is to
reduce discharge fluctuation.
341
The Prandtl pitot tube measures the
velocity at a point in the flow.
342
Pressure drop in packed bed for turbulent flow is given by the ____ equation.
Blake-Plummer
343
In the complete turbulence zone (in rough pipes), the
friction factor is independent of the relative roughness.
344
Which of the following has the minimum compressibility ?
Water at room temperature
345
In case of centrifugal fan or blower, the gas capacity varies as
speed
346
Pick out the wrong statement.
Newton's law of viscosity is not applicable to the turbulent flow of fluid with linear velocity distribution.
347
Pick out the wrong statement.
In a static mass of liquid, the pressure at a point is the same for all liquids.
348
The velocity profile for a Bingham plastic fluid flowing (under laminar conditions) in a pipe is
parabolic near the wall and flat in the middle.
349
Mach number is the ratio of the speed of the
fluid to that of the sound.
350
A piezometer opening measures the ____ fluid pressure.
undisturbed
351
Drag force on the float of a rotameter is(where Q = flow rate of the )
constant
352
The unit of dynamic viscosity in SI unit is
kg/m . sec
353
Pressure drop (Δp) for a fluid flowing in turbulent flow through a pipe is a function of velocity (V) as
V^2
354
Dean number is concerned with the
fluid flow through helical pipes.
355
The equation given below is called the ____ .
F^-0.5 = 4.07 loge (NRe√f)^-0.6
Von-Karman equation
356
Poise is converted into stoke by
dividing by density (gm/c.c).
357
The fluid velocity varies as the square root of the cylindrical pipe diameter in case of steady state laminar flow at constant pressure drop fo ____ fluid.
dilatant
358
Kinetic energy of fluid per unit weight represented by the velocity head is given by
v^2/2gc
359
At a constant speed of the centrifugal pump . it ____ the impeller diameter.
all of these
360
The pressure co-efficient is the ratio of pressure forces to ____ forces.
viscous
361
Vena-contracta formed during flow of a liquid through an orificemeter has
minimum liquid cross-section.
362
As per Newton's law of viscosity, the shear stress for a given rate of angular deformation of fluid is proportional to(where, μ = fluid viscosity)
μ
363
Horsepower increase of a centrifugal gas compressor without altering the volumetric flow rate will ____ the gas discharge pressure.
increase
364
In continuous fluidisation
solids are completely entrained.
365
Glass pipes can be joined by
bell and spigot joint
366
If two capillary tubes of dia 0.5 mm and 1 mm are dipped in a pot containing mercury, then the rise of mercury is
greater in 0.5 mm dia tube.
367
For laminar flow of a shear thinning liquid in a pipe, if the volumetric flow rate is doubled, the pressure gradient will increase by a factor of
2
368
Weber number is the ratio of inertial force to ____ force.
surface tension
369
The curve of metacentre for a floating body ____ the curve of buoyancy.
is the evolute of
370
At what value of crank angle (roughly), no flow of water from or into the air vessel takes place in case of a double acting reciprocating pump ?
40° and 140°
371
The range of a particular rotameter can be increased by
use of floats of different densities.
372
Which of the following is dimensionless ?
Fanning friction factor
373
A liquid is pumped at the rate of 600 litres using 1000 rpm. If the rpm is changed to 1100, the liquid pumped is ____ litres.
660
374
A compressor that takes suction at a pressure below atmospheric and discharge against atmospheric pressure is called a ____ pump.
vacuum
375
A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle system (in SI units) is given below : Δ P/L = 375 x 10^3 VOM + 10.94 x 10^6 V^2OM (SI units) If water is to be used as the fluidising medium, in actual operation, the above bed has a height = 1 m. What is the porosity of the fluidised bed ?
0.7
376
Dimension of kinematic viscosity is
L^2 . T^-1
377
A streamline is a line in flow field,
such that at every point on it, the velocity is tangential to it.
378
While starting an axial flow pump, its delivery valve should be kept
closed
379
____ forces do not act in case of fluid flow.
Tensile
380
Non-colloidal solution is an example of the ____ fluid.
Newtonion
381
Boundary layer separation is caused by the
adverse pressure gradient.
382
Identification of pipelines carrying different liquids and gases is done by the ____ of the pipe.
colour
383
Pick out the correct statement.
A Newtonion fluid obeys Newton's law of cooling.
384
What is the unit of kinematic viscosity in SI unit ?
M^2/sec
385
Hydraulic ____ works on the principle of Pascal's law of transmission of fluid pressure.
press
386
A 2" gate valve fitted in a pipe is replaced by a similar globe valve. Pressure drop in gate valve was Δp. For the same discharge, the pressure drop across globe valve is
> Δp
387
The contraction co-efficient for Borda's mouthpiece (for frictionless fluid) is
0.5
388
Purpose of air lift pump is to
lift water from a well by using compressed air.
389
Pick out the correct statement pertaining to venturimeter.
none of these.
390
For very low pressure and high discharge rate, the compressor used is a/an ____ compressor.
rotary
391
Pumping of a corrosive liquid is generally preferred to be done by a ____ pump, as it can be made of a variety of materials including plastics.
gear
392
What is the speed of sound (m/sec) in ordinary water ?
1500
393
Two piping system are said to be equivalent, when the ____ are same.
fluid flow rate & friction loss
394
Potential function is applicable only for ____ flow.
irrotational
395
Which of the following exemplifies a three dimensional fluid flow ?
Fluid flow at the inlet to a nozzle
396
Volute of a centrifugal pump should be designed in a fashion, such that the
kinetic head gets converted into static head.
397
The head loss due to sudden contraction is proportional to
velocity head
398
Cavitation occurs in a centrifugal pump when the suction pressure is
less than the vapour pressure of the liquid at that temperature.
399
An ideal plastic substance indicates no deformation, when stressed upto yield stress, but behaves like a Newtonion fluid beyond yield stress. Which of the following is an ideal plastic ?
Sewage sludge
400
The capacity of a centrifugal pump Can be increased by increasing the
all of these
401
Which law is followed by the velocity distribution in the turbulent boundary layer?
Logarithmic law
402
The losses in open channel flow generally vary as the
first power of the roughness.
403
Out of the following flow measuring devices, which one incurs the maximum installation cost as well as pressure loss ?
Venturimeter
404
For turbulent fluid flow in pipe, the expression for Prandtl one seventh power law is (where, r = pipe radius, x = distance).
V/Vmax = (x/r)^1/7
405
Which of the following has the maximum compression ratio ?
Vacuum pump
406
Scale up of agitator design requires
all geometrical, dynamic and kinematic similarity.
407
The actual velocity at vena-contracta for flow through an orifice from a reservoir is given by
Cv . √2gH
408
The head loss in turbulent flow in pipe is proportional to(where, V = velocity of fluid through the pipe)
V^2
409
Unsteady non-uniform flow is represented by flow through a/an
expanding tube at increasing rate.
410
Prandtl number is a measure of the
heat conduction to viscosity of a fluid.
411
A centrifugal pump has the following specifications: Power = 4 H.P.; Speed = 800 rpmHead = 8 metresFlow = 1000 litres/minutes.If its speed is halved, then the new head will be ____ metres.
2
412
In hindered settling, the particles are
near each other,
413
A globe valve is the most suitable for applications, in which
fluid flow control is required.
414
____ isused for measuring the static pressure exerted on the wall by a fluid flowing parallel to the wall in a pipeline.
Pitot tube
415
One stoke (unit of kinematic viscosity) is equivalent to
1 cm^2/second
416
Air vessel of a reciprocating pump is initially filled with
compressed air
417
The ratio of inertial forces to gravity forces is called the ____ number.
Froude
418
Power required by a centrifugal pump is proportional to (where, D = diameter, N = r.p.m)
N^3D^5
419
Equivalent length of a pipe fitting is
dependent on Reynolds number.
420
Buckingham-π theorem states that in any physical problem including 'n' quantities having 'm' diamensions, the quantities can be arranged into ____ independent dimensionless parameters.
n-m
421
A fluid which has a linear relationship between the magnitude of applied shear-stress and the resulting rate of deformation is called a/an ____ fluid.
Newtonion
422
Existence of boundary layer in fluid flow is because of the
fluid viscosity
423
In case of laminar flow of fluid through a circular pipe, the
surface of velocity distribution is a paraboloid of revolution, whose volume equals half the volume of circumscribing cylinder.
424
Which of the following facilitates close control of flow of fluids ?
Globe valve
425
For an ideal fluid flow, Reynolds number is
0
426
Stoke's equation is valid in the Reynolds number range
0.01 to 0.1
427
When a fluid flows over a solid surface, the
velocity gradient is zero at the solid surface.
428
Pick out the wrong statement about cavitation.
Large scale cavitation can not damage pipeline, restrict fluid flow and damage steam turbine blades.
429
The maximum delivery pressure of a reciprocating compressor may be about ____ kg/cm2.
4000
430
The velocity for subsonic flow in a pipeline
increases in the downstream direction.
431
Permanent pressure loss in a well designed venturimeter is about ____ percent of the venturi differential.
10
432
The ratio of pressure forces to inertial forces is called the ____ number.
Euler
433
Bernoulli's equation for fluid flow is derived following certain assumptions. Out of the assumptions listed below, which set of assumptions is used in derivation of Bernoulli's equation ?A. Fluid flow is frictionless & irrotational. B. Fluid flow is steady. C. Fluid flow is uniform & turbulent.D. Fluid is compressible.E. Fluid is incompressible.
A, B, E
434
Cavitation in a centrifugal pump results from
low barometric pressure
435
For turbulent flow of newtonion fluid in a circular cross-section pipe, the ratio of maximum to average fluid velocity is
1
436
For flow through a venturi at a particular discharge, the correct relationships among heads at points X, Y, and Z are (1)
h1 > h2 < h3
437
Water is flowing at 1 m/sec through a pipe (of 10 cm I.D) with a right angle bend. The force in Newtons exerted on the bend by water is
5π/2
438
The time of oscillation of a floating body is
a. longer, if metacentric height is increased.
b. independent of the metacentric height.
c. dependent on the buoyant forces only.
d. none of these.
none of these.
439
What is the value of Fanning friction factor f ' for smooth pipe at NRe = 106 approximately ?
0.003
440
Air vessel provided in a reciprocating pump is for
making the friction in pipe uniform.
441
A hydraulic accumulator comprises of
a cylinder and a plunger.
442
Bernoulli's equation for steady, frictionless, continuous flow states that the ____ at all sections is same.
total energy
443
A tube is specified by its
thickness & outer diameter both
444
Prandtl mixing length is
zero at the pipe wall.
445
The hydraulic diameter of an annulus of inner and outer radii Ri and Ro respectively is
2(Ro-Ri)
446
Ratio of inertial forces to surface tension forces is called the ____ number.
Weber
447
In open channel flow in a rectangular channel, the ratio between the critical depth and the initial depth, when a hydraulic jump occurs is
1.84
448
The ratio of inertial forces to viscous forces is called the ____ number.
Reynold
449
Enamels and paints are generally ____ fluid.
pseudo-plastic
450
With the increase in depth, the hydrostatic pressure in an unaccelerated incompressible fluid (in a constant gravitational field)
increases linearly.
451
Flow measurement in an open channel is done by a/an
weir
452
Newton's law of viscosity relates the
shear stress and rate of angular deformation in a fluid.
453
The equivalent diameter for fluid flow through square cross section channel of side 'x', for pressure drop calculation purpose is given by
x
454
Hydraulic radius of 6" x 12" cross-section, is ____ inches.
2
455
Baffles in mixing tanks are provided to
reduce swirling and vortex formation.
456
Which of the following equations is valid for laminar flow of a fluid through packed bed?
Kozney - Karman equation
457
Forces acting on a particle settling in fluid are ____ forces.
gravitational or centrifugal buoyant drag.
458
For a fluid rotating at constant angular velocity about vertical axis as a rigid body, the pressure intensity varies as the
square of the radial distance.
459
In a dry packed bed, the pressure drop will be changed by increasing the flow rate as
V^1.8
460
Specific speed of a centrifugal pump depends upon the ____ head.
none of these
461
Navier-Stokes equation is useful in the analysis of ____ fluid flow problems.
viscous
462
The maximum discharge through a circular channel takes place, when the depth of the fluid flow is ____ times the pipe diameter.
0.95
463
When the head pumped against is less than the head of the fluid used for pumping, the usual device is a/an
airlift
464
Two fluids are flowing through two similar pipes of the same diameter. The Reynold's number is same. For the same flow rate if the viscosity of a fluid is reduced to half the value of the first fluid, the pressure drop will
decrease
465
What is the value of co-efficient of discharge for square edged circular orifice (for β = 0.3 to 0.5) ?
0.61 - 0.63
466
A lubricant 100 times more viscous than water would have a viscosity (in Pa.s)
0.1
467
Nominal Pipe Size (NPS) of a pipe less than 12 inches in diameter indicates its
neither inner nor outer diameter
468
I.D. of 1/4" schedule 40 pipe is 0.364". I.D. of a 1/2" schedule 40 pipe would be ____ inch
0.5
469
Two liquids manometer is used for measuring small pressure differences in
gases
470
A piezometer provided in the pipe measures
static pressure
471
The pump used for irrigation purposes is generally designed for
large capacity & low head.
472
In centrifugal pumps, cavitation occurs, when pressure of the impeller eye or vane becomes
less than liquid vapor pressure.
473
Pressure gradient in the pipe flow is influenced by the
all of these
474
____ pump is the most suitable device for discharging a liquid against a pressure of ≥ 1500 kgf/cm2.
Plunger
475
Boiler feed water pump is usually a ____ pump.
multistage centrifugal
476
Viscosity of a liquid decreases ____ with rise in temperature.
logarithmically
477
In case of a pipe of constant cross-sectional area, the maximum fluid velocity obtainable is
the velocity of sound.
478
Discharge in laminar flow through a pipe varies
as the square of the radius.
479
The lift of a ballon is
due to the weight of the atmospheric air, that it displaces.
480
In which of the following body shapes, the pressure drag is large compared to the friction drag ?
Bluff body
481
Major loss in sudden contraction in pipe flow is due to
flow contraction.
482
Which of the following can be used to create a flow of gas, where no significant compression is required ?
Blower
483
The ratio of actual discharge to theoretical discharge through an orifice is equal to
Cc . Cv
484
A free jet of water of cross-sectional area 0.01m^2 and a velocity of 20 m/s strikes a plate and then flows in a plane parallel to the plate as shown in the figure below. The horizontal component of the force on the support is
4000 N
485
Cp/Cv is termed as
adiabatic constant
486
Which of the following is a Newtonian fluid?
Non-colloidal solution
487
Which of the following valves will incur maximum pressure drop for the same discharge of water ?
Needle valve
488
Pressure drop in a fluidised bed reactor is ____ that in a similar packed bed reactor.
more than
489
In deriving Bernoulli's equation, fluid is assumed to be
incompressible, frictionless, steady, along a streamline.
490
Unit of mass velocity is
kg/m^2. hr
491
With increase in molecular weight of the gas, the head developed by a centrifugal compressor will
decrease
492
Pressure difference between two points in vessels, pipelines or in two different pipelines can be measured by a differential manometer. The pressure difference measured as the mm of water coloumn in case of mercury-water, differential manometer is equal to (where, H = difference in height of mercury column in mm).
12.6 H
493
The boundary layer thickness at a given section along a flat plate ____ with increasing Reynold's number.
decreases
494
Low specific speed of a pump implies that, it is a/an ____ pump.
centrifugal
495
For pumping slurry, one can use a ____ pump.
diaphargm
496
Bernoulli's equation describes the
mechanical energy balance in potential flow.
497
Which law/principle of solid mechanics is similar/equivalent to Newton's law of viscosity in fluid mechanics ?
Hooke's law.
498
When larger particles e.g., grains are subjected to fluidisation, the corresponding bed produced is termed as the ____ bed.
spouted
499
Minimum fluidisation velocity for a specific system depends upon the
all of these
500
Potential flow is characterised by the
irrotational and frictionless flow.
