16-11 fm

1.The continuity equation of fluid mechanics utilises the principle of conservation of

momentum
mass
energy
both (b) & (c)

2.Stoke's law is valid, when the particle Reynolds number is

<1
>1
<5
none of these

3.Which of the following is not a dimension-less parameter ?

Pressure-co-efficient
Froude number
Kinematic viscosity
Weber number

4.In which of the following cases, it is possible for flow to occur from low pressure to high pressure ?

Flow of liquid upward in a vertical pipe.

Flow through a converging section.
Flow of air downward in a pipe.
Impossible in a constant cross-section conduit.

5.The percentage slip in a reciprocating pump set is given by the % of (where, Q1 = actual discharge Q2 =
theoretical discharge)

Q1/Q2
Q2/Q1

6.The blades of a centrifugal impeller are said to be curved forward, if the __________ of the motion of
impeller blades.
inlet tip of a blade curves in a direction opposite to that
outlet tip of a blade curves in a direction opposite to that
inlet tip of a blade is towards the direction
outlet tip of a blade is towards the direction

7.For the same terminal conditions and fitting size, the least friction loss is incurred in a/an
T-joint
union
45° elbow
90°bend

8.A floating/submerged body is always stable, if its centre of gravity

lies above its centre of buoyancy.
and centre of buoyancy coincide.
lies below its centre of buoyancy.
lies above its meta centre.
9.The co-efficient of discharge of an orificemeter is a function of
Reynolds number at the orifice.
ratio of orifice dia to pipe dia.
both (a) and (b).
none of the above parameters, and has a constant value of 0.61.

10.Critical velocity in a pipe flow

increases as fluid viscosity increases.
increases as pipe diameter increases.
independent of fluid density.
none of these.

11.A centrifugal pump designed to pump water is employed to pump a more viscous oil. In the later case,
the pump
develops a lower head.
capacity is reduced.
requires more power.
all (a), (b) and (c).

12.In an incompressible flow of fluid, the fluid

temperature remains constant.
compressibility is greater than zero.
density does not change with pressure & temperature.
is frictionless.

13.The ratio of maximum to average velocity in case of streamline flow between parallel plates is
1
1.5
2
2.5

14.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.
circular
rectangular
triangular
trapezoidal

15.Pressure co-efficient is the ratio of pressure forces to __________ forces.

gravity
inertial
viscous
none of these

16.Which of the following conditions must be satisfied for lift force to be developed ?
The body should be bluff body.
The body should be stream lined.
Circulation around the body is essentially required.
The main stream velocity must approach the velocity of sound in that fluid medium.

17.The Reynolds number for an ideal fluid flow is

4
2100-4000
4000
∞

1.Curve III in the above diagram represents a/an

dilatent fluid
pseudo plastic fluid
ideal plastic
none of these

2.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)?
0.5
1
1.5
2

3.The line traced by a single fluid particle as it moves over a period of time is called __________ line.
stream
path
equipotential
none of these

4.The pressure head on sudden contraction in a horizontal pipe is converted into the __________ head.
elevation
velocity
both (a) & (b)
neither (a) nor (b)

5.A stream tube is that, which has __________ cross-section entirely bounded by stream lines.
a circular
any convenient
a small
a large

6.Colebrook equation for friction factor in turbulent flow is given by, . It

reduces to Nikuradse equation for a value of equal to

0
1
∞
0.5

7.The unit of velocity head is

ft-lb/sec
ft-lb/ft3
ft-lbf/lb
ft-lbf/sec.

8.Which of the following properties of a fluid is responsible for offering resistance to shear ?
Surface tension.
Viscosity.
Specific gravity.
All (a), (b), and (c).

9.Erosion and pits formation on the impeller of a centrifugal pump may be due to
cavitation.
low speed of impeller.
its operation with delivery valve closed for considerable time after starting the pump.
off centering of pump with motor.

10.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.
hyperbola
parabola
semi-circle
semi-ellipse

11.A rotameter works on the principle of __________ pressure drop.

constant
variable
both (a) & (b)
neither (a) nor (b)

12.The effect of solid boundary on the fluid flow is confined to the boundary layer, except for fluids
having high viscosities.
moving at low velocities.
both (a) & (b).
neither (a) nor (b).

13.The excess of the sum of pressure & velocity heads over the vapor pressure of the liquid at the suction is
called the
static submergence.
net positive suction head (NPSH).
cavitation sensitivity.
priming.

14.Piezometric head is the sum of the __________ heads.

elevation & kinetic energy
elevation & pressure
kinetic energy & pressure
none of these

15.Propellers are
axial flow mixers.
low speed impeller.
used for mixingliquids of high viscosity.
radial flow mixers.

16.Which of the following is not an advantage of fluidisation from transfer operation point of view?
Intimate contact of the fluid with all parts of the solid particles.
Lower fluid pumping power requirement.
Minimisation of temperature variation.
Prevention of particle seggregation.

17.Upto what value of 'Mach number', a fluid may be considered as incompressible ?

0.03
0.3
3
10

18.The head developed by a centrifugal pump is largely determined by the

power of the pump.
nature of the liquid being pumped.
angle of the vanes and the speed of the tip of the impeller.
vapour pressure of the liquid.

19.Pick out the wrong statement:

Greater is the kinematic viscosity of the liquid, greater is the thickness of the boundary layer.
Blowers develop a maximum pressure of 2 atmospheres.
Friction losses in pipe fittings are generally expressed in terms of velocity heads.
Fanning friction factor in case of turbulent flow of liquids in pipe depends upon relative roughness &
Reynolds number.
20.Flow rate of high velocity flue gas discharged through a stack to the atmosphere can be most
conveniently measured by a
pitot tube
manometer
rotameter
none of these

21.Potential flow is the flow of

compressible fluids with shear.
compressible fluids with no shear.
incompressible fluids with shear.
incompressible fluids with no shear.

22.The value of critical Reynolds number for pipe flow is

1300
10,000
100,s000
none of these.

23.Mach number is important in a fluid flow problem, when the inertia and __________ forces predominate.
elastic
viscous
gravity
none of these

24.Fanning friction factor is equal to(where, fB = Blassius friction factor).

fB/4
fB/2
4fB
2fB

25.In case of coutte flow, the fluid flow is between two large flat parallel plates with
top plate moving and the bottom plate fixed.
bottom plate moving and the top plate fixed.
both the plates fixed.
both the plates moving.

26.In a stabilised soap bubble, pressure inside it compared to external pressure is

more
less
same
unpredictable

27.The component of acceleration resulting due to unsteady nature of flow is called __________
acceleration.
normal
local
convective
tangential

28.Power required for mixing Newtonion fluids is a function of the

speed of impeller, diameter of impeller & viscosity.
density & viscosity of fluid only.
density of fluid, viscosity of fluid & impeller dia only.
none of these.
29.Multistage compressors are used in industry, because they
reduce the cost of compressor.
reduce the size requirement,
resemble closely to isothermal compression.
are easy to control.

30.The hydrodynamic and thermal boundary layers will merge, when

Prandtl number is one.
Schmidt number tends to infinity.
Nusselt number tends to infinity.
Archimedes number is greater than 10000.

31.Differential manometer measures the

atmospheric pressure.
sub-atmospheric pressure.
pressure difference between two points.
none of these.

32.For a stable equilibrium of a submerged body (where, G and B are centres of gravity & buoyancy
respectively).
G is above B
B is above G
B & coincide
none of these

33.With increase in the ratio of orifice diameter to pipe diameter in case of an orificemeter, the overall
pressure loss
decreases
increases
remains constant
increases linearly

34.The vent valve provided in a liquid handling centrifugal pump is

generally a needle valve.
used to release any gases that might be vapour locking the pump.
helpful in easy removal of samples.
all (a), and (b) and (c).

35.The discharge through a semi-circular weir varies as (where, H = Head of liquid.)

H
H2
H3/2
H1/2

36.The Mach number for hypersonic flow of compressible fluid is

1
>1
>4
<2

37.Boundary layer thickness in turbulent flow over a flat plate increases as(where, d = distance from the
leading edge.)
d
d2/3
d4/5
d1/3
38.Mass velocity in case of steady flow and through a constant cross-section conduit is independent of the
temperature
pressure
both (a) & (b)
neither (a) nor (b)

39.The valve used for very remote and accurate control of fluid is a __________ valve.
needle
globe
gate
butterfly

40.f = 16/NRe, is valid for

turbulent flow
laminar flow through an open channel
steady flow
none of these

41.A mixed flow centrifugal pump

employs such an impeller, through which the flow is a combination of radial & axial flow.
mixes the two fluids before pumping them.
pumps the two fluids separately and then mixes them.
employs impellers in both the radial & axial directions.

42.In centrifugal pump operation, the cavitation can be eliminated by maintaining suction pressure
__________ the vapor pressure of the liquid at the suction temperature.
lower than
higher than
equal to
none of these

43.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)
39.6y
48y
49.2y
58y

44.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 103 VOM + 10.94 x 106 V2OM (SI units)
If water is to be used as the fluidising medium, the minimum fluidisation velocity, VOM is
12 mm/s
16 mm/s
24 mm/s
28 mm/s

45.One dimensional flow implies

flow in a straight line.
steady uniform flow.
unsteady uniform flow.
a flow which does not account for changes in transverse direction.

46.In case of turbulent flow of a Newtonion fluid in a straight pipe, the maximum velocity is equal to
(where, Vavg = average fluid velocity)
Vavg
1.2 Vavg
1.5 Vavg
1.8 Vavg

47.Centrifugal compressors compared to reciprocating compressors

require less space.
have quieter operation.
have lower operating costs.
all (a), (b) and (c).

48.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 )
μ
1/μ
μ
1/μ

49.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
drag on particles
drag on coloumn walls
bed height
bed voidage

50.Slugging occurs in a fluidised bed, if the bed is

narrow
deep
both (a) & (b)
neither (a) nor (b)

1.The terminal velocity of a solid spherical particle falling through a stationary fluid mass in the Stoke's law
range is proportional to the
inverse of fluid viscosity.
square of particle size.
difference in the densities of the particle & fluid.
all (a), (b) and (c).

2.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)?
ε = ε0 + α.t
ε = ε0 + α.t2
ε = ε0 + α.t3
ε = ε0 + α.t4

3.Nominal size of a pipe is an indication of its __________ diameter.

inner
outer
approximate
none of these

4.Fluidised beds are formed, when the

fluid friction is zero
gravity force is less than the fluid friction.
pressure forces equal gravity forces.
sum of the fluid friction and pressure forces is equal and opposite to gravity forces.
5.A fluid is pumped at the rate of 10 lb/sec to a height of 55 ft. The horse power required is __________ hp.
1
10/55
5.5
1/55

6.Pick out the wrong statement:

The vacuum pressure is always the negative gauge pressure.
The pressure of the liquid measured by a piezometer tube is the gauge pressure.
Manometric liquid should have high surface tension.
The point at which the resultant pressure on an immersed surface acts, is known as the centre of gravity.

7.Medium viscosity lubricating oil can be most ideally pumped by a __________ pump.
vane
piston
centrifugal
plunger

8.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
d
d2
d2.5
d4

9.Pump used for the transportation of molten sodium in a fast breader reactor is a/an __________ pump.
reciprocating
plunger
electromagnetic
gear

10.Small pressure differences in liquids is measured using a/an

U-tube manometer.
inclined tube manometer.
pitot tube.
none of these.

11.With increase in pump speed, its NPSH requirement

decreases
increases
remains unaltered
can either increase or decrease ; depends on other factors

12.In the Newton's law range, the terminal velocity of a solid spherical particle falling through a stationary
fluid mass is __________ the fluid viscosity.
directly proportional to
inversely proportional to
inversely proportional to the square root of
independent of

13.Gear pump
is a positive displacement pump.
is a centrifugal pump.
is a non-positive displacement pump.
can be started with delivery valve closed.

14.Most of the centrifugal pumps used in chemical plants are usually __________ driven.
steam
diesel engine
electric motor
gas turbine

15.Check valve provided in the discharge line of a centrifugal pump serves the purpose of controlling the
back flow of fluid in the event of stoppage of pump.
discharge pressure.
flow of liquid during operation of the pump.
all (a), (b) and (c).

16.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
weir
hot wire anemometer
cup and vane aneometer
none of these

17.The time taken for gravity flow of a fixed volume of liquid (as in Redwood viscometer) is directly
proportional to its
absolute viscosity.
ratio of absolute viscosity to density.
density.
Reynolds number.

18.The exit cone angle in case of a standard venturimeter is __________ the entrance cone angle.
smaller than
greater than
equal to
either (a) or (b)

19.Sewage sludge is __________ type of non-Newtonion fluid.

dilatant
Bingham plastic
Pseudo plastic
none of these

20.Ratio of pressure and inertia force gives __________ number.

Weber
Mach
Euler
Froude

21.Permanent loss in a venturimeter is about __________ percent of the pressure drop in theupstream cone.
1
10 .
40
70

22.Volume of liquid displaced by a floating body is equivalent to its

own weight
submerged weight
own volume
submerged volume

23.The __________ is measured by a piezometric opening.

dynamic pressure
static pressure
total pressure
point velocity
24.What is the pipe called which lifts water from a reservoir to a greater height than the initial level in the
supply reservoir ?
Penstock
Siphon
Tunnel
Pressure pipeline

25.Steady uniform flow is represented by flow through a/an

long pipe at constant rate.
long pipe at decreasing rate.
expanding tube at constant rate.
none of these.

26.Pick out the correct statement pertaining to the flow through a converging-diverging tube.
The value of Mach number is always unity at the throat.
No shock wave develops in the tube when the Mach number at exit is greater than unity.
Throughout the converging portion of the tube, the density increases in the downstream direction.
none of these.

27.Cavitation can be prevented by

suitably designing the pump.
maintaining the suction head sufficiently greater than the vapour pressure.
maintaining suction head = developed head.
maintaining suction head lower than the vapour pressure.

28.Assuming flow to be laminar, if the diameter of the pipe is halved, then the pressure drop will
increase
decrease
remain same
be quadrupled

29.Steady flow occurs, when the

conditions change steadily with time.
conditions are the same at the adjacent points at any instant.
conditions do not change with time at any point.
rate of the velocity change is constant.

30.With increase in the ratio of orifice diameter to pipe diameter, the fraction of the orifice pressure
differential that is permanently lost
increases
decreases
remains unchanged
increases exponentially

31.Which of the following two quantities when same, makes one pipe system equivalent to another pipe
system ?
Head & discharge
Length & discharge
Length & diameter
Friction factor & diameter.

32.The kinetic energy correction factor for velocity distribution of laminar flow is
0.5
1.66
1
2

33.Priming of a centrifugal pump is done to

increase the mass flow rate of fluid.
develop effective pressure rise by the pump.
avoid chances of separation inside the impeller.
none of these.

34.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
90
60
45
30

35.For pipes that must be broken at intervals for maintenance, the connector used should be a/an
union
tee
reducer
elbow

36.A fluid is the one, which

cannot remain at rest under the action of shear force.
continuously expands till it fills any container.
is incompressible.
permanently resists distortion.

37.One horsepower is equal to

550 lbf.ft/second
550 kgf.m/second
both (a) and (b)
550 lbf.ft./hr

38.For one dimensional flow of an incompressible fluid in unsteady state in x-direction, the continuity
equation is given by

39.A fluid is moving at critical flow condition (NRe = 2100) through a pipe of dia 3 cms.

Velocity of flow is __________ cm/sec.

7
700
7000
630

40.Capillary rise of mercury in a small diameter tube is proportional to (where, d = diameter of the tube, σ =
surface tension of mercury)
d
1/d
σ
l/σ
41.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
Δp
2Δp
Δp2
Δp/2

42.Fluid flow in a/an __________ is an example of pressure flow.

partially filled pipeline
pipe
open channel
river.

43.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).
Re
Re
1/Re
Re-1/2

44.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
26
42
269
325

45.A 0.5 m high bed made up of a 1 mm dia glass sphere (density 2500 kg/m3 ) is to be fluidised by water
(density 1000 kg/m3 ). If at the point of incipient fluidisation, the bed voidage is 40%, the pressure drop
across the bed is
4.4 KPa
2.94 KPa
3.7 KPa
none of these

46.Absolute viscosity of a fluid is a function of the __________ of the fluid.

motion
pressure & temperature
shearing stress
both(b)&(c)

47.Select the wrong statement pertaining to flow of an incompressible fluid through a venturimeter.
For frictionless flow, the fluid pressure entering the venturi meter will be exactly equal to that leaving the
venturimeter.
Discharge of fluid through a venturimeter depends upon the gage difference irrespective of the orientation
of venturimeter.
Venturimeter occupies less space than an orificemeter.
Venturimeter incurs less power loss compared to an equivalent orificemeter.

48.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
increase
decrease
remain same
data insufficient to predict pressure drop
49.The bulk modulus of elasticity of a liquid
is zero for incompressible liquid.
decreases with pressure.
is independent of temperature & pressure.
increases with pressure.

50.The inherent characteristic of an equal percentage valve relating flow rate 'q' with valve stem movement
'x' are described by the equation

1.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
0.1
0.55
0.95
1.85

2.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.

ρL . Vg
ρL . A.Hg
ρL . Vg/2
ρL .Vg/3

3.A relief valve

provides back pressure for a cylinder.
unloads a pump.
is a directional control valve.
none of these.

4.An isentropic process is the one, in which

pv = constant
pvr = constant
pvr = constant, and process is reversible
none of these

5.The distribution of shear stress in a stream of fluid in a circular tube is

linear with radius for turbulent flow only.
linear with radius for laminar flow only.
linear with radius for both laminar & turbulent flow.
parabolic with radius for both laminar & turbulent flow.

6.For motion of spherical particles in a stationary fluid, the drag co-efficient in hindered settling compared
to that in free settling is
more
less
equal
more or less, depending on the type of particle

7.Specific speed of a centrifugal pump relates it with another pump having the
dynamic similarity
same efficiency
same speed
geometrical similarity

8.Air vessel fitted to a reciprocating pump

increases the work done.
decreases the work done.
causes cavitation.
results in non-uniform discharge.

9.Deformation drag, which is caused by widespread deformation of fluid around the immersed body
occurs when NRe is very small.
is primarily a friction drag.
is independent of body length.
depends mainly on cross-sectional shape.

10.In isotropic turbulence, the __________ are equal to each other.

temporal velocity components
mean square of velocity fluctuations in the three co-ordinate directions
root mean square of velocity fluctuations in the three co-ordinate directions
none of these

11.Viscosity of water is about __________ times that of air at room temperature.

15
55
155
1050

12.Net positive suction head (NPSH) of a centrifugal pump must be

greater than the vapour pressure of the liquid.
less than the vapour pressure of the liquid.
equal to the vapour pressure of the liquid.
less than barometric pressure.

13.Actual lift of a pump is always less than the theoretical lift and is limited by the
specific gravity & temperature of the liquid.
leakage & pressure decreasing at higher elevations.
frictional resistance through pipes, fittings & passages.
all (a), (b) and (c).

14.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?
Discharge of water by a centrifugal pump being run at a constant rpm.
Water flow in the suction and discharge pipe of a reciprocating pump.
Water discharge from a vertical vessel in which constant level is maintained.
Low velocity flow of a highly viscous liquid through a hydraulically smooth pipe.

15.Nature of fluid flow during the opening of a valve in a pipeline is

laminar
unsteady
steady
uniform

16.The __________ pressure is measured by a static tube.

dynamic
static
total
none of these

17.The speed of a sound wave in a gas is analogous to the speed of

an elementary wave in an open channel.
flow in an open channel.
a disturbance travelling upstream in moving fluid.
none of these.

18.Mercury is an ideal barometric fluid mainly due to its

high density.
low compressibility.
low capillary action.
very low vapor pressure.

19.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 ?
Inertial and drag forces are important.
Drag, gravitational and buoyancy forces are impportant.
Drag force and gravitational forces are important.
None of the above.

20.A gas
signifies absence of density.
can resist shearing action.
is incompressible.
is a supercritical vapor.

21.Pitot tube measures the __________ of a fluid.

pressure
average velocity
average flow rate
point velocity

22.Which of the following is not dimension-less?

Froude number
Kinematic viscosity
Pressure co-efficient
None of these

23.In laminar flow through a round tube, the discharge varies

linearly as the viscosity.
inversely as the pressure drop.
inversely as the viscosity.
as the square of the radius.
24.Which is not a variable head meter ?
Venturimeter
Pitot tube
Rotameter
None of these

25.The pipe wall thickness is minimum for a pipe of given nominal size having schedule number
160
120
80
40

26.Reynolds number for flow of water at room temperature through 2 cm dia pipe at an average velocity of 5
cm/sec is around
2000
10
100
1000

27.Centrifugal pumps as compared to reciprocating pumps

run at a lower speed for the same discharge.
do not need priming.
deliver fluid with pulsating/fluctuating discharge.
can be run with discharge line valve closed for a short interval.

28.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 ?
Rotation
Translation
Linear deformation
Angular deformation

29.In which type of fluid flow, the velocity of flow of fluid changes from point to point in the fluid at any
instant ?
Rotational
Unsteady
Turbulent
Non-uniform

30.The continuity equation in ideal fluid flow states that

net rate of inflow into any small volume must be zero.
energy is not constant along a streamline.
energy is constant along a streamline.
there exists a velocity potential.

31.Bernoulli's equation is not applicable, when the flow is

irrotational.
incompressible.
viscous.
all (a), (b) & (c).

32.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)
x
πx
2x
x/2
33.Centre of pressure of a plane surface of arbitrary shape immersed vertically in a static mass of fluid
lies above the centroid of the plane surface.
is independent of the specific weight of the fluid.
is different for different fluids.
is at the centroid of the plane surface.

34.Drag co-efficient for flow past immersed body is the ratio of __________ to the product of velocity head
and density.
shear stress
shear force
average drag per unit projected area
none of these

35.Creeping flow around a sphere is defined, when particle Reynolds number is

< 2100
< 0.1
> 2.5
< 500

36.Open channel liquid flow is most conveniently measured by a

hot wire anemometer
notch
rotameter
segmental orifice

37.Toothpaste is a
Bingham plastic
pseudoplastic
Newtonion liquid
dilatent

38.Slurries can be most conveniently pumped by a __________ pump.

screw
reciprocating
gear
centrifugal

39.Volute type of casing is provided in a centrifugal pump to

convert velocity head to pressure head.
convert pressure head to velocity head,
reduce the discharge fluctuation.
increase the discharge.

40.Each term of the Bernoulli's equation written in the form, , represents the

total energy per unit

mass
volume
specific weight
none of these

41.In a free vortex, the

velocity changes linearly with radial distance.
flow is necessarily rotational.
radial component of velocity is same everywhere.
stream lines are not circular.
42.Pick out the wrong statement.
The eddy viscosity is a function of the type of turbulence involved.
The eddy viscosity is a fluid property.
The viscosity of gas increases with increase in temperature.
The viscosity of a liquid increases with decrease in temperature.

43.The velocity distribution in direction normal to the direction of flow in plane Poiseuille flow is
hyperbolic
parabolic
linear
none of these

44.In fluid flow, the stagnation point is defined as a point, where the __________ is zero.
flow velocity
pressure
total energy
all (a), (b) and (c)

45.A special type of liquid transporting device is the diffuser pump, in which __________ are minimised.
bearing losses
disk friction
shock losses
cavitation

46.Which of the following is most prone to pulsating discharge flow ?

Centrifugal pump
Reciprocating pump
Gear pump
Axial flow pump

47.A streamline is
the line connecting the mid-points of flow cross-sections.
defined for uniform flow only.
drawn normal to the velocity vector at every point.
always the path of a particle.

48.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)
Df + Bf = Wf
Df = Bf + Wf
Df + Bf + Wf =0
none of these

49.Drag is defined as the force exerted by the

fluid on the solid in a direction opposite to flow.
fluid on the solid in the direction of flow.
solid on the fluid.
none of these.

50.The boundary layer is that part of a moving fluid, in which the fluid velocity is
affected by the fluid flow pressure.
constant.
affected by the presence of a solid boundary.
all (a), (b) and (c).

1.__________ is an example of axial flow impeller.

Paddle
Turbine
Propeller
all (a), (b) and(c)

2.Froude number is not a factor

for Reynolds number greater than 300.
when there is no vortex formation.
for unbaffled tank.
none of these.

3.If three pipes of different diameters, lengths & friction factors are connected in parallel, then (where, Q =
flow rate, V= fluid velocity f = friction factor).
Q = Q1 + Q2 + Q3
V1 = V2 = V3
Q1 = Q2 = Q3
f = f1 + f2 + f3

4.Horsepower requirement for given pump capacity depends upon the

specific gravity of the liquid
suction lift
discharge head
all (a), (b) and (c)

5.Bernoulli's equation accounts for the

various momentums
various masses
different forms of mechanical energy
none of these

6.__________ pumps are a group of vacuum pumps.

Hyter
Sump
Mono
Submerged

7.Plunger pumps are used for

higher pressure
slurries
viscous mass
none of these

8.What is the ratio of displacement thickness to nominal thickness for a linear distribution of velocity in the
boundary layer on a flat plate ?
0.5
1
1.5
2

9.In turbulent flow, the

fluid particles move in an orderly manner.
momentum transfer is on molecular scale only.
shear stress is caused more effectively by cohesion than momentum transfer.
shear stresses are generally larger than in a similar laminar flow.

10.Momentum correction factor used in fluid flow problems accounts for the
change in direction of flow.
change in total energy.
change in pressure.
non uniform direction of velocities at inlet & outlet sections.
11.Drag co-efficient for motion of spherical particles in a stationary fluid in the stoke's law range is

12Design of the casing of centrifugal pump should be such as to minimise the

back flow through impeller
loss of kinetic head
loss of static head
none of these

13.Which of the following is used for pumping crude oil from oil well ?
Single stage centrifugal pump
Gear pump
Screw pump
Duplex/triplex reciprocating pump

14.The energy loss in flow through ven-turimeter is less than that through flow nozzle, because in case of a
flow nozzle, the
length is shorter.
throat diameter is more.
sudden expansion of flow in the downstream occurs.
distance between the throat and the inlet is more.

15.__________ flow means the flow of incompressible fluid with no shear.

Potential
Streamline
Creep
Boundary layer

16.The continuity equation

relates mass flow rate along a stream tube.
relates work and energy.
stipulates that Newton's second law of motion must be satisfied at every point in the fluid.
none of these.

17.The energy loss over a length of pipeline according to Darcy-Weisbach equation for pipe flow is.....the
mean velocity of flow.
directly proportional to
directly proportional to square of
inversely proportional to
inversely proportional to square of

18.Pressure drop in a packed bed for laminar flow is given by the __________ equation.
Kozney-Karman
Blake-Plummer
Leva's
Fanning friction factor
19.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.
Newtonion
pseudoplastic
dilatent
Bingham plastic

20.Stoke's law is valid, when NRe, p is less than

2
100
2100
700

21.Froude number is the ratio of

shear stress to gravitational stress.
drag stress to shear stress.
inertial stress to shear stress.
inertial stress to gravitational stress.

22.Normal depth in open channel flow is the depth of flow in the channel
corresponding to uniform flow.
measured normal to the channel bed.
corresponding to steady flow.
none of these.

23.Which of the following flow measuring devices is an area meter ?

Venturimeter
Orifice meter
Anemometer
Rotameter

24.With decrease in particle size to be fluidised by a particular fluid, the operating range of fluidisation
velocity
widens
squeezes
does not change
unpredictable from the data

25.Diaphragm valves are used for handling __________ fluids.

corrosive
viscous
non-Newtonion
solid suspended

26.The schedule number of a pipe is an indication of its

size
roughness
material density

wall thickness
27.Minimum porosity for fluidisation is
that corresponding to static bed.
that corresponding to completely fluidised bed.
the porosity of the bed when true fluidisation begins.
less than that of the' static bed.

28.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
increase
decrease
remain same
data insufficient to predict

29.Steady non-uniform flow is exemplified by flow through a/an

long pipe at constant rate.
long pipe at decreasing rate.
expanding tube at increasing rate.
expanding tube at constant rate.

30.The maximum depth from which a centrifugal pump can draw water is
dependent on the speed of the pump.
dependent on the power of the pump.
34 feet.
150 feet.

31.Hot wire anemometer is used to measure the

velocity of liquids.
temperature of liquids.
velocity of gases.
pressure of liquids.

32.Propeller type centrifugal pumps are most suitable for

high capacity at high heads.
high capacity at low heads.
low capacity at high heads.
low capacity at low heads.

33.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.
Newtonion
dilatant
pseudoplastic
non-Newtonion

34.Momentum transfer in laminar flow of fluids results due to the

viscosity
density
velocity gradient
none of these

35.The capillary rise of mercury is maximum in glass tube of dia __________ mm.
0.5
1
2
5

36.Diaphragm pumps are used to transport

solids
liquids
fluids
slurries

37.For steady ideal fluid flow, the Bernoulli's equation states that the
velocity is constant along a stream line.
energy is constant throughout the fluid
energy is constant along a stream line, but may vary across stream lines
none of these
38.In case of a centrifugal pump, the theoretical head developed is dependent on the __________ the
impeller.
speed of
diameter of
fluid velocity leaving
all (a), (b) and (c)

39.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.
10
100
1000
10000

40.Choose the set of pressure intensities that are equivalent.

4.33 psi, 10 ft. of water, 8.83 inches of Hg.
4.33 psi, 10 ft. of water, 20.7 inches of Hg.
10 psi, 19.7 ft. of water, 23.3 inches of Hg.
10 psi, 19.7 ft. of water, 5.3 inches of Hg.

41.Hydraulic mean radius for flow through packed bed of spherical particle of size, 'Dp, with porosity 'ε' is

42.Pick out the wrong statement about a streamline.

It is always parallel to the main direction of the fluid flow.
It is a line across which there is no flow and it is equivalent to a rigid boundary.
Streamlines intersect at isolated point of zero velocity and infintie velocity.
The fluid lying between any two streamlines can be considered to be in isolation and the streamline spacing
varies inversely as the velocity.

43.The most serious disadvantage of an orificemeter is that

it is not very accurate.
it is very costly.
most of the pressure drop is not recoverable.
it is not suitable for measuring gas flow.

44.The discharge through a rectangular weir varies as

H1/2
H5/2
H2/5
H3/2

45.In case of supersonic flow of a fluid through pipeline, the 'Mach number' is
0
1
<1
>1
46.A centrifugal pump has the following specifications:
Power = 4 H.P.; Speed = 800 rpm
Head = 8 metres
Flow = 1000 litres/minutes.
If its speed is halved, the power consumed now will be __________ hp.
0.5
2
4
1

47.Transition length for turbulent flow in smooth pipe is equal to __________ times the pipe diameter.
0.5
5
50
100

48.Disc compensators are provided in large diameter fuel gas carrying pipelines to
keep the pipe in proper orientation.
make the pipe joint leak-proof.
account for contraction/expansion of pipe due to temperature changes of the surroundings.
account for the pressure variation side the pipeline.

49.Discharge from a 24 inch pipe of water at 10 ft/sec will be __________ ft3/sec.

7.65
32.36
48.22
125.6

50.Paper pulp is an example of __________ fluid.

dilatant
bingham plastic
Newtonion
pseudoplastic

1.Forces acting on a particle settling in fluid are __________ forces.

gravitational & buoyant.
centrifugal & drag.
gravitational or centrifugal buoyant drag.
external, drag & viscous.

2.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.
radial distance linearly.
inverse of the radial distance.
elevation along vertical direction.

3.In a dry packed bed, the pressure drop will be changed by increasing the flow rate as
V1.8
V-0.8
V
V-1

4.Specific speed of a centrifugal pump depends upon the __________ head.

suction
delivery
manometric
none of these
5.Navier-Stokes equation is useful in the analysis of __________ fluid flow problems.
non-viscous
viscous
turbulent
rotational

6.The maximum discharge through a circular channel takes place, when the depth of the fluid flow is
__________ times the pipe diameter.
0.25
0.5
0.66
0.95

7.When the head pumped against is less than the head of the fluid used for pumping, the usual device is
a/an
ejector
blower
injector
airlift

8.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
increase
decrease
remain unchanged
data insufficient to predict relative pressure drop.

9.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
0.5 - 0.75
0.75 - 0.90
0.35 - 0.55

10.A lubricant 100 times more viscous than water would have a viscosity (in Pa.s)
0.01
0.1
1
10

11.Nominal Pipe Size (NPS) of a pipe less than 12 inches in diameter indicates its
inner diameter
outer diameter
thickness
neither inner nor outer diameter

12.I.D. of 1/4" schedule 40 pipe is 0.364". I.D. of a 1/2" schedule 40 pipe would be __________ inch
4.728
0.5
0.622
0.474

13.A pump operating under specific conditions delivers insufficient quantity of liquid. This may be set right
by
decreasing the size of the inlet pipe.
increasing the size of the inlet pipe.
lowering the pump position.
both (b) and (c).
14.Two liquids manometer is used for measuring small pressure differences in
liquids
gases
mixture of hydrocarbons
none of these

15.A piezometer provided in the pipe measures

friction factor
static pressure
dynamic pressure
none of these

16.The pump used for irrigation purposes is generally designed for

large capacity & high head.
large capacity & low head.
small capacity & high head.
small capacity & low head.

17.In centrifugal pumps, cavitation occurs, when pressure of the impeller eye or vane becomes
less than atmospheric pressure.
more than liquid vapor pressure.
less than liquid vapor pressure.
more than atmospheric pressure.

18.Pressure gradient in the pipe flow is influenced by the

diameter of pipe.
velocity of the fluid.
density & viscosity of the fluid.
all (a), (b) and (c).

19.__________ pump is the most suitable device for discharging a liquid against a pressure of ≥ 1500
kgf/cm2.
Centrifugal
Piston
Plunger
Vane

20.Boiler feed water pump is usually a __________ pump.

reciprocating
gear
multistage centrifugal
diaphragm

21.Viscosity of a liquid decreases __________ with rise in temperature.

exponentially
linearly
logarithmically
none of these

22.In case of a pipe of constant cross-sectional area, the maximum fluid velocity obtainable is
the velocity of sound.
dependent on its cross-sectional area.
dependent on fluid viscosity.
dependent on fluid density.

23.Discharge in laminar flow through a pipe varies

as the square of the radius.
inversely as the pressure drop.
inversely as the viscosity.
as the square of the diameter.

24.The lift of a ballon is

increased, as it rises to a higher altitude.
due to the weight of the atmospheric air, that it displaces.
not dependent on the temperature of the atmosphere.
none of these.

25.In which of the following body shapes, the pressure drag is large compared to the friction drag ?
Stream line body
Two dimensional body
Bluff body
None of these

26.Major loss in sudden contraction in pipe flow is due to

boundary friction.
flow contraction.
expansion of flow after sudden contraction.
none of these.

27.Which of the following can be used to create a flow of gas, where no significant compression is required
?
Reciprocating compressor
Blower
Axial flow compressor
Centrifugal compressor

28.The ratio of actual discharge to theoretical discharge through an orifice is equal to

Cc . Cv
Cc . Cd
Cv . Cd
Cd/Cv

29.A free jet of water of cross-sectional area 0.01m2 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

200 N
400 N
2000 N
4000 N

30.Cp/Cv is termed as
adiabatic constant
Mach number
Weber number
Prandtl number

31.Which of the following is a Newtonian fluid?

Rubber latex
Sewage sludge
Quicksand
Non-colloidal solution

32.Which of the following valves will incur maximum pressure drop for the same discharge of water ?
Globe valve
Gate valve
Needle valve
Butterfly valve

33.Pressure drop in a fluidised bed reactor is __________ that in a similar packed bed reactor.
less than
more than
same as
none of these

34.In deriving Bernoulli's equation, fluid is assumed to be

incompressible, frictionless, steady, along a streamline.
uniform, steady, incompressible, along a streamline.
steady, density being pressure dependent, frictionless.
none of these.

35.Unit of mass velocity is

kg/hr
kg/m2. hr
kg/m2
kg/m3. hr

36.
With increase in molecular weight of the gas, the head developed by a centrifugal compressor will
decrease
increase
remain same
unpredictable

37.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).
H
12.6 H
13.6 H
14.6 H

38.The boundary layer thickness at a given section along a flat plate __________ with increasing Reynold's
number.
increases
decreases
remains same
may increase or decrease
39.Low specific speed of a pump implies that, it is a/an __________ pump.
axial flow
centrifugal
mixed flow
none of these

40.Pressure drop for laminar fluid flow through a circular pipe is given by

41.For pumping slurry, one can use a __________ pump.

reciprocating
diaphargm
centrifugal
pneumatic

42.Bernoulli's equation describes the

mechanical energy balance in potential flow.
kinetic energy balance in laminar flow.
mechanical energy balance in turbulent flow.
mechanical energy balance in boundary layer.

43.For laminar flow of a fluid through a packed bed of spheres of diameter d, the pressure drop per unit
length of bed depends upon the sphere diameter as
d
d2
d4

44.Which law/principle of solid mechanics is similar/equivalent to Newton's law of viscosity in fluid

mechanics ?
Archimedes principle.
Newton's second law of motion.
Hooke's law.
Newton's third law of motion.

45.When larger particles e.g., grains are subjected to fluidisation, the corresponding bed produced is
termed as the __________ bed.
spouted
sluggish
boiling
teeter

46.Minimum fluidisation velocity for a specific system depends upon the

particle size.
fluid viscosity.
density of both the particle & the fluid.
all (a), (b) and (c).
47.Potential flow is characterised by the
irrotational and frictionless flow.
irrotational and frictional flow.
one in which dissipation of mechanical energy into heat occurs.
formation of eddies within the stream.

48.For the production of very high vacuum, a __________ pump is normally used.
diffusion
centrifugal
jet ejector
piston

49.In parallel pipe problems, the

head loss is the same through each pipe.
discharge is the same through all the pipes.
total head loss is equal to the sum of the head losses through each pipe.
none of these
.
50.Fluid flow through a packed bed is represented by the __________ equation.
Fanning's
Ergun's
Hagen-Poiseuille's
none of these