(6) Fluid Mechanics Flashcards
1
Q
The fluid property, due to which, mercury does not wet the glass is
A
2
Q
Laminar flow of a Newtonion fluid ceases to exist, when the Reynolds number exceeds
A
3
Q
When the momentum of one fluid is used for moving another fluid, such a device is called a/an
A
4
Q
The head loss in turbulent flow in a pipe varies
A
5
Q
Most commonly used joint in the underground pipe lines is the
A
6
Q
Schedule number of a pipe, which is a measure of its wall thickness, is given by
A
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
8
Q
With increasing flow rate, the hydraulic efficiency of a centrifugal pump
A
9
Q
The velocity profile for turbulent flow through a closed conduit is
A
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
11
Q
Water hammer in a pipeline results from the
A
12
Q
Molten soap mass is transported by a __________ pump.
A
13
Q
Which of the following denotes the effect of compressibility in fluid flow ?
A
14
Q
Nominal size of the discharge pipe of a pump is usually __________ the nominal size of the inlet pipe.
A
15
Q
The terminal velocity of a small sphere settling in a viscous fluid varies as the
A
16
Q
If the discharge of a centrifugal pump is throttled, then its suction lift
A
17
Q
Foot valves provided in pumps are __________ valves.
A
18
Q
At high Reynolds number
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19
Q
Power loss in an orificemeter is __________ that in a venturimeter.
A
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
21
Q
What is the normal range of exit cone angle of a venturimeter ?
A
22
Q
The dimension of dynamic viscosity is
A
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
24
Q
The pitot static tube does not measure the __________ pressure.
A
25
The fluid in which the shearing stress within it is proportional to the velocity gradient across the sheared section, is called a __________ fluid.
26
The ratio of the depth of flow to the hydraulic radius for the most economical trapezoidal section, in open channel flow is
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).
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)
29
The maximum delivery pressure of compressors can be upto __________ atmospheres.
30
Dimension of surface tension is(where, F = force, L = length)
31
Which of the following is not a dimension-less parameter ?
32
Co-efficient of velocity is __________ the coefficient of discharge.
33
All pipes of a particular nominal size have the same
34
For the transfer of solution of thick slurry, the pump used is a __________ pump.
35
Which of the following is not concerned with the fluid-particle interaction ?
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.
37
Pressure drag does not depend upon the
38
Dimension of absolute viscosity is
39
__________ pumps are axial flow pumps.
40
Brownian movement is prominent in the particle size range of __________ microns in case of settling of a particle in a fluid.
41
For a particle settling in water at its terminal settling velocity, which of the following is true ?
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
43
Pick out the correct statement.
44
Shear stress in a fluid flowing in a round pipe
45
The resistance wire used in a hot wire anemometer for conducting electrical current is made of
46
Two dimensional stream function
47
What causes cavitation in centrifugal pump ?
48
Draining of shallow pits or sump is done by a sump pump, which is a __________ pump.
49
A hydraulic ram acts as a/an __________ pump.
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
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).
52
The line of action of the buoyant force passes through the centre of gravity of the
53
Pick out the wrong statement.
54
The friction factor for turbulent flow in a hydraulically smooth pipe
55
The pressure at a point in a fluid is not the same in all directions, when the fluid is viscous and
56
What causes convective acceleration in fluid flow ?
57
The Stoke's stream function applies to the
58
Slugging in a fluidised bed can be avoided by using
59
The ratio of width to depth for the most economical rectangular section in open channel flow is
60
The simple pitot tube measures the __________ pressure.
61
Capacity of a hydraulic accumulator is defined in terms of maximum
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)
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.
64
Manometers measure the __________ pressure.
65
Which of the following fluid forces are not considered in the Navier-Stoke's equation?
66
Which of the following may be termed as a variable orifice flowmeter ?
67
In turbulent flow, a rough pipe has the same friction factor as a smooth pipe
68
Air vessel provided in a reciprocating pump
69
Bernoulli's equation is dependent on the
70
The capacity of an accumulator is the maximum
71
With increase in the temperature, viscosity of a liquid
72
Vena-contracta pressure tapping is at a distance __________ from the position of an orificemeter fitted in a pipe of internal diameter 'd'
73
The pump impeller and the turbine runner in a hydraulic torque converter
74
Reciprocating pumps compared to centrifugal pumps
75
The fluid property which matters for fall-ing rain drops to acquire spherical shape is its
76
The simple pitot tube does not measure the
77
Boundary layer separation occurs when the
78
The head loss in turbulent flow in a pipe varies
79
For flow through an orifice from a reservoir, the actual velocity at the vena con-tracta is given by
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
81
For the free settling of a spherical particle through a fluid, the slope of, CD-log NRe , plot is
82
A centrifugal pump loses prime after starting. The reason of this trouble may be
83
Venturimeter and orificemeter measures the __________ of the fluid.
84
Surge tanks are provided in high pressure water pipelines to
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.
86
Isotropic turbulence occurs
87
The co-efficient of drag and lift for an incompressible fluid depends on the
88
Euler's equation of motion states, that at every point, the
89
Hydraulic intensifier is used for increasing the
90
Which of the following is the 'Blaussius equation', relating friction factor to the Reynolds number ?
91
Hydrometer measures the specific gravity of liquids based on the principles of buoyancy. Pycnometer is used to measure the specific gravity of
92
Euler's equation of motion is a statement expressing
93
During ageing of fluid carrying pipes, the
94
Pick out the wrong statement.
95
Mass velocity is independent of temperature & pressure, when the flow is
96
Very small pressure difference (< 5 mm water coloumn) can be most conveniently measured by a/an __________ manometer.
97
For pipe flows, head is proportional to __________ at constant capacity(where, D = pipe diameter).
98
The energy equation, (1) (E = internal energy/mass), is applicable to
99
A differential pressure cell is used for
100
If more than two branches of pipes are to be connected at the same point, then use a/an
101
In case of a centrifugal pump, the ratio of total delivered pressure to pressure developed with the impeller is called the __________ efficiency.
102
Acceleration head in a reciprocating pump
103
The ratio of inertial forces to elastic forces is called the __________ number.
104
Fluid flow at increasing rate through a diverging pipe is an example of __________ flow.
105
The temperature in isentropic flow
106
A fluid element has a velocity V = -y^2 . xi + 2yx^2 . j. The motion at (x, y) = (l/√2, 1) is
107
Check in a centrifugal pump is
108
Drag force acting on a body does not depend upon the
109
Centrifugal pump is normally classified on the basis of the
110
Where does the maximum stress occur in case of laminar flow of incompressible fluid in a closed conduit of diameter 'd'?
111
In case of isentropic flow, the speed of sound in an ideal gas is proportional to (where, T = absolute temperature )
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
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)
114
In an incompressible fluid, the density is
115
Check valves are used
116
Velocity distribution for flow between two fixed parallel plates
117
Priming is needed in a __________ pump.
118
Which of the fluid forces are not considered in the Reynold's equation of flow ?
119
For ideally incompressible fluid, the Mach number will be
120
A mono pump is a __________ pump.
121
Higher specific speed (200-500) of a centrifugal pump indicates that the pump is of __________ flow type.
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.
123
Theoretical head developed by a centrifugal pump does not depend upon the __________ the impeller.
124
In case of isentropic flow, the speed of sound in an ideal gas is proportional to (where M = molecular weight of the gas)
125
Boundary layer separation is caused by the
126
With increase in temperature, the vapor pressure of liquids
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.
128
The ratio of wall drag to total drag in the Stoke's law range is
129
Rotary vacuum pumps can reduce the absolute pressure to as low as __________ mm Hg.
130
A pitched-blade turbine draws __________ a straight blade turbine.
131
The most suitable flow measuring device for the fluid flow measurement in a very large diameter pipeline is a
132
A centrifugal pump is called a turbine pump, if it is having a
133
Remote control valve is a __________ valve.
134
Which of the following quantities are computed by using the hydraulic radius for non-circular ducts ?
135
Centre of pressure in an immersed body is __________ the centre of gravity.
136
The centre of pressure is
137
Pascal law is not applicable for a/an __________ fluid.
138
In a fluidised bed reactor
139
The flow of a liquid through tapering pipe at a constant rate is an example of __________ flow.
140
Pick out the correct statement pertaining to transition/ entrance length in fluid flow.
141
A perfect gas
142
In a/an __________ , the flow rate of fluids is obtained by measuring the difference between the impact and the static pressure.
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 .
144
Speed of sound in an ideal gas depends on its
145
A centrifugal pump designed for handling water (μ = 1 cp) will deliver __________ when pumping a thicker oil (μ = 30 cp).
146
If 'x' is the depth of flow in an open channel of large width, then the hydraulic radius is equal to
147
In fluid flow, the boundary layer separation can not occur
148
For a given fluid flow rate, which of the following incurs maximum head loss ?
149
Which of the following assumptions enables the Euler's equation of motion to be integrated ?
150
A fluid whose apparent viscosity increases with shear rate is termed as the __________ fluid.
151
Which of the following is the most common pump for pumping either raw sewage or sludge ?
152
Transition length for a turbulent fluid entering into a pipe is around __________ times the pipe diameter.
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
154
Reciprocating pumps are not able to compete with the centrifugal pump for industrial use, mainly because these pumps have
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)
156
Which of the following pipe bends will incur the largest head loss ?
157
Which is the most efficient and best for measuring very small flow rate of gases ?
158
When the water is warm, the height to which it can be lifted by a pump
159
Pipes having diameter 14 inches or more are designated by their
160
Viscosity of water at 40°C lies in the range of
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.
162
The dimension of kinematic viscosity is
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
164
Turbulent flow generally occurs for cases involving
165
Lower BWG means __________ of the tube.
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.
167
The Prandtl mixing length is
168
N^2Re/NFr is called the __________ number.
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)
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
171
Self-priming centrifugal pump can be used for
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
173
Bernoull's equation does not apply to the functioning of a/an
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'?
175
Pascal's law is valid, only when the fluid is
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.
177
The pressure head of a flow meter remains constant for
178
A venturimeter can not be used for the direct measurement of
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
180
Which of the following is used for very accurate measurement of flow of gas at low velocity ?
181
In Newton's law range, the drag co-efficient for the motion of spherical particle in a stationary fluid is
182
A pressure of 10 m head of water is equivalent to __________ kN/m2.
183
A pressure head of 320 metres of water in meters of CCl4 (sp.gr = 1.6) will be
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
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.
186
Maintenance cost of a __________ pump for a particular duty is the least.
187
Choking in case of pipe flow means that a
188
Velocity of liquid hydrocarbon fuels in a pipeline can not be measured by magnetic flowmeters, because their __________ is very low/small.
189
The nominal size of a hose pipe is specified by its
190
Transition from laminar flow to turbulent flow is aided by the
191
For flow of fluids through packed bed, the superficial velocity is
192
Cd is always __________ Cc.
193
Buoyant force
194
Which of the following is an undesirable property of a manometric liquid ?
195
Characteristic curves for a centrifugal pump plotted against its capacity is shown in the diagram. x, y and z denote respectively (1)
196
Liquid delivery by centrifugal pump starts, only when the head developed by it is equal to the __________ head.
197
The speed of sound in an ideal gas varies as the
198
The maximum head that can be developed by a single impeller is __________ ft.
199
The ratio of hydrodynamic boundary layer to thermal boundary layer thickness in case of liquid metals is
200
The general relationship between speed N, head H, power P and discharge Q for a centrifugal pump is
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 ?
202
Foot valve provided in the pump is a __________ valve.
203
The discharge co-efficient for an orificemeter does not depend upon the
204
Which of the following options will facilitate the achievement of a very high head (say 30 metres) in case of a centrifugal pump?
205
An equipotential line is __________ to the velocity vector at every point.
206
Path followed by water jet issuing from the bottom of a water tank will be a
207
Which of the following produces maximum pressure difference for transportation of gases ?
208
For flow through a venturi at a particular discharge, the correct relationships among velocities at point X, Y and Z would be (1)
209
Drag co-efficient in hindered settling is __________ that in free settling.
210
Efficiency of power transmission (η) through a circular pipe is given by (ht - hf)/ht, which has a maximum value of __________ percent.
211
One dimensional fluid flow implies the
212
__________ forces act on a particle moving through a stationary fluid.
213
In frictional fluid flow, the quantity, (1) , is
214
Hydraulic radius is the ratio of
215
The unit of bulk modulus of elasticity for a liquid in S.I. unit is
216
Power requirement of fans having constant wheel diameter varies __________ fan speed.
217
In the low Reynolds number region, the drag force on a sphere is proportional to
218
The continuity equation
219
Experimental study of laminar fluid flow through a circular tube was conducted by
220
The most economical flow control valve for use with large diameter pipes is a
221
Each term in Bernaulli's equation represents the __________ of the fluid.
222
Which of the following is a dimensionless parameter ?
223
If the head over the triangular notch is doubled, the discharge will increase by __________ times.
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
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
226
Interstage coolers are provided in a multistage compressor to
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.
228
Reynolds number is the ratio of
229
For the manometer set up shown in the figure, the pressure difference PA - PB is given by (1)
230
The discharge through a venturimeter depends upon
231
N. second/m^2 is
232
The distance between metacentre and __________ is called metacentric height.
233
Check valve is used for __________ flow.
234
Capacity of a rotary gear pump can be varied by
235
For a given Reynolds number, in a hydraulically smooth pipe, further smoothening __________ the friction factor.
236
Power number is the ratio of
237
The momentum correction factor for the velocity distribution of laminar flow is
238
For the same flow rate of a fluid, the pressure drop is the least for
239
The valve commonly used in pipes larger than 2" dia is a
240
Foot valves are provided in the suction line of a centrifugal pump to
241
An ideal fluid is
242
In area meter (e.g., rotameter), with increase in the fluid flow rate, the
243
In power law, (1) , then the fluid is
244
The buoyant force acting on a floating body is dependent on the
245
A Newtonion fluid is that
246
In case of end to end connection of two or more pipes in series, the __________ each pipe.
247
Which of the following equations applies to the fluid flow through a packed bed for very large Reynolds number ?
248
The flow of gas along a pipe in the direction of decreasing pressure causes decrease in its
249
Centrifugal pump can't be used to pump
250
A stream line is
251
Quicksand is an example of a __________ fluid.
252
Correction for capillary effect in manometers (used for pressure measurement) need not be applied, if diameter of the manometer tube is __________ mm.
253
Differential manometer measures the
254
The pressure and power requirement of a gas fan at constant speed & capacity varies __________ the gas density.
255
Boundary layer thickness in laminar flow over a flat plate increases as(where, d = distance from the leading edge.)
256
Gradually varied flow in open channel is a/an __________ flow.
257
The line of action of the buoyant force acts through the
258
Cavitation in a centrifugal pump can be avoided by keeping the
259
Vane anemometer
260
The peripherial velocity at inlet of a centrifugal pump having inlet diameter of 25 cms and rotating at 950 rpm is __________ m/sec.
261
Laminar flow is characterised by the nonexistence of
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.
263
Select the correct practical example of steady non-uniform flow.
264
Hydraulic diameter for non-circular ducts is equal to __________ times the area of flow divided by the perimeter.
265
Terminal velocity is
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.
267
For an incompressible fluid, the bulk modulus of elasticity is
268
A fluid is a substance, that
269
The pressure intensity is the same in all directions at a point in a fluid
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.
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 ?
272
Boundary layer exists in flow
273
Rubber latex is an example of __________ fluid.
274
The frictional resistance in laminar flow does not depend on the
275
A venturimeter measures the
276
Gradually varying fluid flow is an example of __________ flow.
277
Drag is the force component exerted on an immersed object,
278
To handle smaller quantity of fluid at higher discharge pressure, use a __________ pump.
279
Cocks are used to control
280
The dimension of surface tension is
281
Pick out the correct statement.
282
The friction factor is
283
Rubber latex is an example of a __________ .fluid.
284
Which of the following factors does not contribute to the pressure drop in a pipeline ?
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
286
Working of a __________ pump characterises mixed flow.
287
The rate of change of moment of momentum represents the __________ by the fluid.
288
Cd for the orifice plate varies from
289
The discharge through a V-notch weir varies as
290
Water flow rate in a pipe of 3.5 metres diameter can be most economically and conveniently measured by a/an
291
The specific speed of a pump is defined as the speed of a unit of such a size, that it
292
In case of venturimeters, friction losses are about __________ percent of maximum velocity head.
293
With increase in the schedule number of a pipe of a particular nominal size, the
294
Turbine impeller
295
Friction produced by the formation of wakes is called the __________ friction.
296
Various efficiencies of a centrifugal pump are related as (where, ηm = mechanical efficiency ηv = volumetric efficiency. ηma = manometric efficiency ηo = overall efficiency)
297
When the pipe Reynold's number is 6000, the flow is generally
298
With a constant diameter impeller of a centrifugal pump
299
For water, when the pressure increases, the viscosity
300
Location of vena-contracta in an orificemeter does not depend upon the
301
At low Reynolds number
302
For laminar flow through a closed conduit
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.
304
Unsteady uniform flow is represented by flow through a/an
305
If Blausius or Darcey friction factor is 'f1' then the Fanning friction factor is equal to
306
Pick out the wrong statement pertaining to fluid flow.
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
308
While starting a centrifugal pump, its delivery valve should be kept
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
310
Sewage sludge is an example of the __________ fluid.
311
Multistage centrifugal pumps are generally used for
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
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
314
Cavitation in a pump creates so many undesirable effects. Out of the following, which is not an undesirable effect created by cavitation ?
315
For a specific centrifugal air blower operating at constant speed & capacity, the power requirement and pressure vary
316
Capillary tube method of viscosity measurement is based on the
317
It is possible to integrate an automatic flow controller to a
318
For liquid flow through a packed bed, the superficial velocity as compared to average velocity through the channel in the bed is
319
For a reciprocating pump, the indicator diagram is the graph between the
320
High specific speed of a pump implies that, it is a/an __________ pump.
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
322
One poise (unit of absolute/dynamic viscosity) is equivalent to one
323
The equation relating friction factor to Reynold number, f^-0.5 = 4 loge (NRe/f)^-0.4, is called the __________ equation.
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 ?
325
For an unstable equilibrium of a floating body (where, M = metacentre.)
326
Which of the following can be used for the direct measurement of volumetric flow rate of slurry ?
327
A pipe is defined as 'hydraulically smooth', if the friction factor
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
329
Delivery of insufficient quantity of liquid by a pump may be caused by
330
In case of a __________ the energy of flow is considerably decreased downstream of the machine.
331
With increase in the shear rate, the apparent viscosity of pseudoplastic fluids
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
333
Purpose of hydraulic accumulator is to
334
Pick out the wrong statement.
335
Purpose of relief valve in a reciprocating pump is to
336
Select the correct statement.
337
In case of turbulent flow of fluid through a circular pipe, the
338
What is the maximum theoretical suction lift (metres) of a reciprocating pump ?
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.
340
Function of air vessel provided in a reciprocating pump is to
341
The Prandtl pitot tube measures the
342
Pressure drop in packed bed for turbulent flow is given by the __________ equation.
343
In the complete turbulence zone (in rough pipes), the
344
Which of the following has the minimum compressibility ?
345
In case of centrifugal fan or blower, the gas capacity varies as
346
Pick out the wrong statement.
347
Pick out the wrong statement.
348
The velocity profile for a Bingham plastic fluid flowing (under laminar conditions) in a pipe is
349
Mach number is the ratio of the speed of the
350
A piezometer opening measures the __________ fluid pressure.
351
Drag force on the float of a rotameter is(where Q = flow rate of the )
352
The unit of dynamic viscosity in SI unit is
353
Pressure drop (Δp) for a fluid flowing in turbulent flow through a pipe is a function of velocity (V) as
354
Dean number is concerned with the
355
The equation given below is called the __________ .
F^-0.5 = 4.07 loge (NRe√f)^-0.6
356
Poise is converted into stoke by
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.
358
Kinetic energy of fluid per unit weight represented by the velocity head is given by
359
At a constant speed of the centrifugal pump . it __________ the impeller diameter.
360
The pressure co-efficient is the ratio of pressure forces to __________ forces.
361
Vena-contracta formed during flow of a liquid through an orificemeter has
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)
363
Horsepower increase of a centrifugal gas compressor without altering the volumetric flow rate will __________ the gas discharge pressure.
364
In continuous fluidisation
365
Glass pipes can be joined by
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
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
368
Weber number is the ratio of inertial force to __________ force.
369
The curve of metacentre for a floating body __________ the curve of buoyancy.
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 ?
371
The range of a particular rotameter can be increased by
372
Which of the following is dimensionless ?
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.
374
A compressor that takes suction at a pressure below atmospheric and discharge against atmospheric pressure is called a __________ pump.
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 ?
376
Dimension of kinematic viscosity is
377
A streamline is a line in flow field,
378
While starting an axial flow pump, its delivery valve should be kept
379
__________ forces do not act in case of fluid flow.
380
Non-colloidal solution is an example of the __________ fluid.
381
Boundary layer separation is caused by the
382
Identification of pipelines carrying different liquids and gases is done by the __________ of the pipe.
383
Pick out the correct statement.
384
What is the unit of kinematic viscosity in SI unit ?
385
Hydraulic __________ works on the principle of Pascal's law of transmission of fluid pressure.
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
387
The contraction co-efficient for Borda's mouthpiece (for frictionless fluid) is
388
Purpose of air lift pump is to
389
Pick out the correct statement pertaining to venturimeter.
390
For very low pressure and high discharge rate, the compressor used is a/an __________ compressor.
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.
392
What is the speed of sound (m/sec) in ordinary water ?
393
Two piping system are said to be equivalent, when the __________ are same.
394
Potential function is applicable only for __________ flow.
395
Which of the following exemplifies a three dimensional fluid flow ?
396
Volute of a centrifugal pump should be designed in a fashion, such that the
397
The head loss due to sudden contraction is proportional to
398
Cavitation occurs in a centrifugal pump when the suction pressure is
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 ?
400
The capacity of a centrifugal pump Can be increased by increasing the
401
Which law is followed by the velocity distribution in the turbulent boundary layer?
402
The losses in open channel flow generally vary as the
403
Out of the following flow measuring devices, which one incurs the maximum installation cost as well as pressure loss ?
404
For turbulent fluid flow in pipe, the expression for Prandtl one seventh power law is (where, r = pipe radius, x = distance).
405
Which of the following has the maximum compression ratio ?
406
Scale up of agitator design requires
407
The actual velocity at vena-contracta for flow through an orifice from a reservoir is given by
408
The head loss in turbulent flow in pipe is proportional to(where, V = velocity of fluid through the pipe)
409
Unsteady non-uniform flow is represented by flow through a/an
410
Prandtl number is a measure of the
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.
412
In hindered settling, the particles are
413
A globe valve is the most suitable for applications, in which
414
__________ isused for measuring the static pressure exerted on the wall by a fluid flowing parallel to the wall in a pipeline.
415
One stoke (unit of kinematic viscosity) is equivalent to
416
Air vessel of a reciprocating pump is initially filled with
417
The ratio of inertial forces to gravity forces is called the __________ number.
418
Power required by a centrifugal pump is proportional to (where, D = diameter, N = r.p.m)
419
Equivalent length of a pipe fitting is
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.
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.
422
Existence of boundary layer in fluid flow is because of the
423
In case of laminar flow of fluid through a circular pipe, the
424
Which of the following facilitates close control of flow of fluids ?
425
For an ideal fluid flow, Reynolds number is
426
Stoke's equation is valid in the Reynolds number range
427
When a fluid flows over a solid surface, the
428
Pick out the wrong statement about cavitation.
429
The maximum delivery pressure of a reciprocating compressor may be about __________ kg/cm2.
430
The velocity for subsonic flow in a pipeline
431
Permanent pressure loss in a well designed venturimeter is about __________ percent of the venturi differential.
432
The ratio of pressure forces to inertial forces is called the __________ number.
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.
434
Cavitation in a centrifugal pump results from
435
For turbulent flow of newtonion fluid in a circular cross-section pipe, the ratio of maximum to average fluid velocity is
436
For flow through a venturi at a particular discharge, the correct relationships among heads at points X, Y, and Z are (1)
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
438
The time of oscillation of a floating body is
439
What is the value of Fanning friction factor f ' for smooth pipe at NRe = 106 approximately ?
440
Air vessel provided in a reciprocating pump is for
441
A hydraulic accumulator comprises of
442
Bernoulli's equation for steady, frictionless, continuous flow states that the __________ at all sections is same.
443
A tube is specified by its
444
Prandtl mixing length is
445
The hydraulic diameter of an annulus of inner and outer radii Ri and Ro respectively is
446
Ratio of inertial forces to surface tension forces is called the __________ number.
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
448
The ratio of inertial forces to viscous forces is called the __________ number.
449
Enamels and paints are generally __________ fluid.
450
With the increase in depth, the hydrostatic pressure in an unaccelerated incompressible fluid (in a constant gravitational field)
451
Flow measurement in an open channel is done by a/an
452
Newton's law of viscosity relates the
453
The equivalent diameter for fluid flow through square cross section channel of side 'x', for pressure drop calculation purpose is given by
454
Hydraulic radius of 6" x 12" cross-section, is __________ inches.
455
Baffles in mixing tanks are provided to
456
Which of the following equations is valid for laminar flow of a fluid through packed bed?
457
Forces acting on a particle settling in fluid are __________ forces.
458
For a fluid rotating at constant angular velocity about vertical axis as a rigid body, the pressure intensity varies as the
459
In a dry packed bed, the pressure drop will be changed by increasing the flow rate as
460
Specific speed of a centrifugal pump depends upon the __________ head.
461
Navier-Stokes equation is useful in the analysis of __________ fluid flow problems.
462
The maximum discharge through a circular channel takes place, when the depth of the fluid flow is __________ times the pipe diameter.
463
When the head pumped against is less than the head of the fluid used for pumping, the usual device is a/an
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
465
What is the value of co-efficient of discharge for square edged circular orifice (for β = 0.3 to 0.5) ?
466
A lubricant 100 times more viscous than water would have a viscosity (in Pa.s)
467
Nominal Pipe Size (NPS) of a pipe less than 12 inches in diameter indicates its
468
I.D. of 1/4" schedule 40 pipe is 0.364". I.D. of a 1/2" schedule 40 pipe would be __________ inch
469
Two liquids manometer is used for measuring small pressure differences in
470
A piezometer provided in the pipe measures
471
The pump used for irrigation purposes is generally designed for
472
In centrifugal pumps, cavitation occurs, when pressure of the impeller eye or vane becomes
473
Pressure gradient in the pipe flow is influenced by the
474
__________ pump is the most suitable device for discharging a liquid against a pressure of ≥ 1500 kgf/cm2.
475
Boiler feed water pump is usually a __________ pump.
476
Viscosity of a liquid decreases __________ with rise in temperature.
477
In case of a pipe of constant cross-sectional area, the maximum fluid velocity obtainable is
478
Discharge in laminar flow through a pipe varies
479
The lift of a ballon is
480
In which of the following body shapes, the pressure drag is large compared to the friction drag ?
481
Major loss in sudden contraction in pipe flow is due to
482
Which of the following can be used to create a flow of gas, where no significant compression is required ?
483
The ratio of actual discharge to theoretical discharge through an orifice is equal to
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
485
Cp/Cv is termed as
486
Which of the following is a Newtonian fluid?
487
Which of the following valves will incur maximum pressure drop for the same discharge of water ?
488
Pressure drop in a fluidised bed reactor is __________ that in a similar packed bed reactor.
489
In deriving Bernoulli's equation, fluid is assumed to be
490
Unit of mass velocity is
491
With increase in molecular weight of the gas, the head developed by a centrifugal compressor will
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).
493
The boundary layer thickness at a given section along a flat plate __________ with increasing Reynold's number.
494
Low specific speed of a pump implies that, it is a/an __________ pump.
495
For pumping slurry, one can use a __________ pump.
496
Bernoulli's equation describes the
497
Which law/principle of solid mechanics is similar/equivalent to Newton's law of viscosity in fluid mechanics ?
498
When larger particles e.g., grains are subjected to fluidisation, the corresponding bed produced is termed as the __________ bed.
499
Minimum fluidisation velocity for a specific system depends upon the
500
Potential flow is characterised by the
501
For the production of very high vacuum, a __________ pump is normally used.
502
In parallel pipe problems, the
503
Fluid flow through a packed bed is represented by the __________ equation.
504
__________ is an example of axial flow impeller.
505
Froude number is not a factor
506
If three pipes of different diameters, lengths & friction factors are connected in parallel, then (where, Q = flow rate, V= fluid velocity f = friction factor).
507
Horsepower requirement for given pump capacity depends upon the
508
Bernoulli's equation accounts for the
509
__________ pumps are a group of vacuum pumps.
510
Plunger pumps are used for
511
What is the ratio of displacement thickness to nominal thickness for a linear distribution of velocity in the boundary layer on a flat plate ?
512
In turbulent flow, the
513
Momentum correction factor used in fluid flow problems accounts for the
514
Design of the casing of centrifugal pump should be such as to minimise the
515
Which of the following is used for pumping crude oil from oil well ?
516
The energy loss in flow through ven-turimeter is less than that through flow nozzle, because in case of a flow nozzle, the
517
__________ flow means the flow of incompressible fluid with no shear.
518
The continuity equation
519
The energy loss over a length of pipeline according to Darcy-Weisbach equation for pipe flow is.....the mean velocity of flow.
520
Pressure drop in a packed bed for laminar flow is given by the __________ equation.
521
The fluid velocity varies as the cube of the cylinderical pipe diameter in case of steady state laminar flow at constant pressure drop for __________ fluid.
522
Stoke's law is valid, when NRe, p is less than
523
Froude number is the ratio of
524
Normal depth in open channel flow is the depth of flow in the channel
525
Which of the following flow measuring devices is an area meter ?
526
With decrease in particle size to be fluidised by a particular fluid, the operating range of fluidisation velocity
527
Diaphragm valves are used for handling __________ fluids.
528
The schedule number of a pipe is an indication of its
529
Minimum porosity for fluidisation is
530
A centrifugal pump used to pump water is used to pump an oil with specific gravity of 0.8 at the same rate. The power consumption will now
531
Steady non-uniform flow is exemplified by flow through a/an
532
The maximum depth from which a centrifugal pump can draw water is
533
Hot wire anemometer is used to measure the
534
Propeller type centrifugal pumps are most suitable for
535
The fluid velocity varies as the square of the cylindrical pipe diameter, in case of steady state laminar flow at constant pressure drop, for __________ fluid.
536
Momentum transfer in laminar flow of fluids results due to the
537
The capillary rise of mercury is maximum in glass tube of dia __________ mm.
538
Diaphragm pumps are used to transport
539
For steady ideal fluid flow, the Bernoulli's equation states that the
540
In case of a centrifugal pump, the theoretical head developed is dependent on the __________ the impeller.
541
A hydraulic press has a ram of 10 cms in diameter and a plunger of 1 cm in diameter. The force required on the plunger to raise a weight of 10 tons on the ram is __________ kg.
542
Choose the set of pressure intensities that are equivalent.
543
Pick out the wrong statement about a streamline.
544
The most serious disadvantage of an orificemeter is that
545
The discharge through a rectangular weir varies as
546
In case of supersonic flow of a fluid through pipeline, the 'Mach number' is
547
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 power consumed now will be __________ hp.
548
Transition length for turbulent flow in smooth pipe is equal to __________ times the pipe diameter.
549
Disc compensators are provided in large diameter fuel gas carrying pipelines to
550
Discharge from a 24 inch pipe of water at 10 ft/sec will be __________ ft3/sec.
551
Paper pulp is an example of __________ fluid.
552
The ratio of the depth of flow to the diameter of the channel for maximum discharge in a circular channel in open channel flow is
553
A conical tank with a bottom opening of cross-sectional area A is filled with water and is mounted on supports as shown in the figure. What is the force F with which plate X must be pushed up to prevent water from leaking ? Assume that the density of air is negligible as compared to the density of water ρL. (1)
554
A relief valve
555
An isentropic process is the one, in which
556
The distribution of shear stress in a stream of fluid in a circular tube is
557
For motion of spherical particles in a stationary fluid, the drag co-efficient in hindered settling compared to that in free settling is
558
Specific speed of a centrifugal pump relates it with another pump having the
559
Air vessel fitted to a reciprocating pump
560
Deformation drag, which is caused by widespread deformation of fluid around the immersed body
561
In isotropic turbulence, the __________ are equal to each other.
562
Viscosity of water is about __________ times that of air at room temperature.
563
Net positive suction head (NPSH) of a centrifugal pump must be
564
Actual lift of a pump is always less than the theoretical lift and is limited by the
565
In case of unsteady fluid flow, conditions & flow pattern change with the passage of time at a position in a flow situation. Which of the following is an example of unsteady flow?
566
Nature of fluid flow during the opening of a valve in a pipeline is
567
The __________ pressure is measured by a static tube.
568
The speed of a sound wave in a gas is analogous to the speed of
569
Mercury is an ideal barometric fluid mainly due to its
570
A spherical particle is falling slow in a viscous liquid such that Reynolds number is less than 1. Which statement is correct for this situation ?
571
A gas
572
Pitot tube measures the __________ of a fluid.
573
Which of the following is not dimension-less?
574
In laminar flow through a round tube, the discharge varies
575
Which is not a variable head meter ?
576
The pipe wall thickness is minimum for a pipe of given nominal size having schedule number
577
Reynolds number for flow of water at room temperature through 2 cm dia pipe at an average velocity of 5 cm/sec is around
578
Centrifugal pumps as compared to reciprocating pumps
579
What type of motion the fluid element undergoes, when it changes from one position to another position, such that the angle between the two sides change ?
580
In which type of fluid flow, the velocity of flow of fluid changes from point to point in the fluid at any instant ?
581
The continuity equation in ideal fluid flow states that
582
Bernoulli's equation is not applicable, when the flow is
583
The equivalent diameter for pressure drop calculation for a duct of square cross-section is given by(where, x = each side of the square duct)
584
Centre of pressure of a plane surface of arbitrary shape immersed vertically in a static mass of fluid
585
Drag co-efficient for flow past immersed body is the ratio of __________ to the product of velocity head and density.
586
Creeping flow around a sphere is defined, when particle Reynolds number is
587
Open channel liquid flow is most conveniently measured by a
588
Toothpaste is a
589
Slurries can be most conveniently pumped by a __________ pump.
590
Volute type of casing is provided in a centrifugal pump to
591
Each term of the Bernoulli's equation written in the form, (1) , represents the total energy per unit
592
In a free vortex, the
593
Pick out the wrong statement.
594
The velocity distribution in direction normal to the direction of flow in plane Poiseuille flow is
595
In fluid flow, the stagnation point is defined as a point, where the __________ is zero.
596
A special type of liquid transporting device is the diffuser pump, in which __________ are minimised.
597
Which of the following is most prone to pulsating discharge flow ?
598
A streamline is
599
Which of the following relationship is valid for the equilibrium position of the float in a rotameter ?(where, Df= Drag force on the float Bf = Buoyant force on the float Wf = Weight of the float)
600
Drag is defined as the force exerted by the
601
The boundary layer is that part of a moving fluid, in which the fluid velocity is
602
The terminal velocity of a solid spherical particle falling through a stationary fluid mass in the Stoke's law range is proportional to the
603
Which of the following equations as suggested by Colebrook and White gives the increase in roughness of a new surface (ε0) with age/time (t) (where, ε = roughness of the surface after time't'. α = a co-efficient to be experimentally determined)?
604
Nominal size of a pipe is an indication of its __________ diameter.
605
Fluidised beds are formed, when the
606
A fluid is pumped at the rate of 10 lb/sec to a height of 55 ft. The horse power required is __________ hp.
607
Pick out the wrong statement:
608
Medium viscosity lubricating oil can be most ideally pumped by a __________ pump.
609
In a fully turbulent flow (Re > 105) in a pipe of diameter 'd', for a constant pressure gradient, the dependence of volumetric flow rate of an incompressible fluid is
610
Pump used for the transportation of molten sodium in a fast breader reactor is a/an __________ pump.
611
Small pressure differences in liquids is measured using a/an
612
With increase in pump speed, its NPSH requirement
613
In the Newton's law range, the terminal velocity of a solid spherical particle falling through a stationary fluid mass is __________ the fluid viscosity.
614
Gear pump
615
Most of the centrifugal pumps used in chemical plants are usually __________ driven.
616
Check valve provided in the discharge line of a centrifugal pump serves the purpose of controlling the
617
Venturimeters, orificemeters and nozzles are used to measure the fluid discharge from a pipeline. The average fluid velocity in a pipeline can be measured by a/an
618
The time taken for gravity flow of a fixed volume of liquid (as in Redwood viscometer) is directly proportional to its
619
Sewage sludge is __________ type of non-Newtonion fluid.
620
Ratio of pressure and inertia force gives __________ number.
621
Permanent loss in a venturimeter is about __________ percent of the pressure drop in theupstream cone.
622
Volume of liquid displaced by a floating body is equivalent to its
623
The __________ is measured by a piezometric opening.
624
What is the pipe called which lifts water from a reservoir to a greater height than the initial level in the supply reservoir ?
625
Steady uniform flow is represented by flow through a/an
626
Pick out the correct statement pertaining to the flow through a converging-diverging tube.
627
Cavitation can be prevented by
628
Assuming flow to be laminar, if the diameter of the pipe is halved, then the pressure drop will
629
Steady flow occurs, when the
630
With increase in the ratio of orifice diameter to pipe diameter, the fraction of the orifice pressure differential that is permanently lost
631
Which of the following two quantities when same, makes one pipe system equivalent to another pipe system ?
632
The kinetic energy correction factor for velocity distribution of laminar flow is
633
Priming of a centrifugal pump is done to
634
Bed pressure drop in an air fluidised bed of catalyst particles (ρp = 200 kg/m3, Dp = 0.05 cm) of 60 cm bed depth and bed porosity of 0.5 expressed in cm of water (manometer) is
635
For pipes that must be broken at intervals for maintenance, the connector used should be a/an
636
A fluid is the one, which
637
A fluid (1) is moving at critical flow condition (NRe = 2100) through a pipe of dia 3 cms. Velocity of flow is __________ cm/sec.
638
Capillary rise of mercury in a small diameter tube is proportional to (where, d = diameter of the tube, σ = surface tension of mercury)
639
The pressure drop per unit length of pipe incurred by a fluid 'X' flowing through pipe is Δp. If another fluid 'Y' having both the specific gravity & density just double of that of fluid 'X', flows through the same pipe at the same flow rate/average velocity, then the pressure drop in this case will be
640
Fluid flow in a/an __________ is an example of pressure flow.
641
In the laminar boundary layer flow over a flat plate, the ratio (δ/x) varies as :(where, 'δ' is the boundary layer thickness and 'x' is the distance from the leading edge in the direction of flow).
642
A rotameter through which air at room temperature and atmospheric pressure is flowing gives a certain reading for a flow rate of 100 cc/sec. If helium (molecular weight 4) is used and rotameter shows the same reading, the flow rate (cc/sec) is
643
A 0.5 m high bed made up of a 1 mm dia glass sphere (density 2500 kg/m^3 ) is to be fluidised by water (density 1000 kg/m^3 ). If at the point of incipient fluidisation, the bed voidage is 40%, the pressure drop across the bed is
644
Select the wrong statement pertaining to flow of an incompressible fluid through a venturimeter.
645
Reynolds number for water flow through a tube of I.D. 5 cm is 1500. If a liquid of 5 centipoise viscosity and 0.8 specific gravity flows in the same pipe at the same velocity, then the pressure drop will
646
The bulk modulus of elasticity of a liquid
647
Curve III in the above diagram represents a/an
648
What is the ratio of total kinetic energy of fluid passing per second to the value obtained on the basis of average velocity (for laminar flow through a circular pipe)?
649
The line traced by a single fluid particle as it moves over a period of time is called __________ line.
650
A stream tube is that, which has __________ cross-section entirely bounded by stream lines.
651
Colebrook equation for friction factor in turbulent flow is given by, (1) . It reduces to Nikuradse equation for a value of (1) equal to
652
The unit of velocity head is
653
Which of the following properties of a fluid is responsible for offering resistance to shear ?
654
Erosion and pits formation on the impeller of a centrifugal pump may be due to
655
The velocity profile exhibited by laminar flow of Newtonion fluids is such that the velocity distribution w.r.t. radius of the circular pipe is a/an __________ with the apex at the centre line of the pipe.
656
The excess of the sum of pressure & velocity heads over the vapor pressure of the liquid at the suction is called the
657
Piezometric head is the sum of the __________ heads.
658
Propellers are
659
Which of the following is not an advantage of fluidisation from transfer operation point of view?
660
Upto what value of 'Mach number', a fluid may be considered as incompressible ?
661
The head developed by a centrifugal pump is largely determined by the
662
Pick out the wrong statement:
663
Flow rate of high velocity flue gas discharged through a stack to the atmosphere can be most conveniently measured by a
664
Potential flow is the flow of
665
The value of critical Reynolds number for pipe flow is
666
Mach number is important in a fluid flow problem, when the inertia and __________ forces predominate.
667
Fanning friction factor is equal to(where, fB = Blassius friction factor).
668
In case of coutte flow, the fluid flow is between two large flat parallel plates with
669
In a stabilised soap bubble, pressure inside it compared to external pressure is
670
The component of acceleration resulting due to unsteady nature of flow is called __________ acceleration.
671
Power required for mixing Newtonion fluids is a function of the
672
Multistage compressors are used in industry, because they
673
The hydrodynamic and thermal boundary layers will merge, when
674
Differential manometer measures the
675
For a stable equilibrium of a submerged body (where, G and B are centres of gravity & buoyancy respectively).
676
With increase in the ratio of orifice diameter to pipe diameter in case of an orificemeter, the overall pressure loss
677
The vent valve provided in a liquid handling centrifugal pump is
678
The discharge through a semi-circular weir varies as (where, H = Head of liquid.)
679
The Mach number for hypersonic flow of compressible fluid is
680
Boundary layer thickness in turbulent flow over a flat plate increases as(where, d = distance from the leading edge.)
681
The valve used for very remote and accurate control of fluid is a __________ valve.
682
f = 16/NRe, is valid for
683
A mixed flow centrifugal pump
684
In centrifugal pump operation, the cavitation can be eliminated by maintaining suction pressure __________ the vapor pressure of the liquid at the suction temperature.
685
A rectangular surface 3' x 4', has the lower 3 edge horizontal and 6' below a free oil surface (sp. gr. 0.8). The surface inclination is 300 with the horizontal. The force on one side of the surface is(where, y = specific weight of water)
686
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, the minimum fluidisation velocity, VOM is
687
One dimensional flow implies
688
In case of turbulent flow of a Newtonion fluid in a straight pipe, the maximum velocity is equal to (where, Vavg = average fluid velocity)
689
Centrifugal compressors compared to reciprocating compressors
690
For laminar flow of Newtonion fluids through a circular pipe, for a given pressure drop and length & diameter of pipe, the velocity of fluid is proportional to(where, μ = fluid viscosity )
691
Umf is the minimum fluidisation velocity for a bed of particles. An increase in the superficial gas velocity from 2 Umf to 2.5 Umf results in (all velocities are smaller than the entrainment velocity of the particles) no change in the
692
Stoke's law is valid, when the particle Reynolds number is
693
Which of the following is not a dimension-less parameter ?
694
In which of the following cases, it is possible for flow to occur from low pressure to high pressure ?
695
The blades of a centrifugal impeller are said to be curved forward, if the __________ of the motion of impeller blades.
696
For the same terminal conditions and fitting size, the least friction loss is incurred in a/an
697
A floating/submerged body is always stable, if its centre of gravity
698
Critical velocity in a pipe flow
699
A centrifugal pump designed to pump water is employed to pump a more viscous oil. In the later case, the pump
700
In an incompressible flow of fluid, the fluid
701
The ratio of maximum to average velocity in case of streamline flow between parallel plates is
702
A weir is used to measure the large water discharge rate from a river or from an open channel. A weir is not of __________ shape.
703
Pressure co-efficient is the ratio of pressure forces to __________ forces.
704
Which of the following conditions must be satisfied for lift force to be developed ?
705
The Reynolds number for an ideal fluid flow is
