fm 2

Question 1

A globe valve is the most suitable for applications, in which

fluid flow control is required.
fluid contains dispersed solid particles.
valve is required to be either fully open or fully closed.
one way flow is required.

Answer 1

A

Question 2

__________ isused for measuring the static pressure exerted on the wall by a fluid flowing parallel to the wall in a pipeline.

Venturimeter
Pressure gauge
Pitot tube
Orificemeter

Answer 2

C

Question 3

One stoke (unit of kinematic viscosity) is equivalent to

1 cm2/second
1 m2/second
1 gm/cm. second
1 kg . m/second

Answer 3

A

Question 4

Air vessel of a reciprocating pump is initially filled with
atmospheric air
compressed air
water
none of these

Answer 4

B

Question 5

The ratio of inertial forces to gravity forces is called the __________ number.
Mach
Froude
Euler
Weber

Answer 5

B

Question 6

Power required by a centrifugal pump is proportional to (where, D = diameter, N = r.p.m)

N2D3
ND2
N2D
N3D5

Answer 6

D

Question 7

Equivalent length of a pipe fitting is
dependent on Reynolds number.
independent of Reynolds number.
dependent on the length of the pipe.
none of these.

Answer 7

A

Question 8

Buckingham-π theorem states that in any physical problem including ‘n’ quantities having ‘m’ diamensions, the quantities can be arranged into __________ independent dimensionless parameters.
m
n
n-m
n/m

Answer 8

C

Question 9

A fluid which has a linear relationship between the magnitude of applied shear-stress and the resulting rate of deformation is called a/an __________ fluid.
Newtonion
Non-Newtonion
ideal
incompressible

Answer 9

A

Question 10

Existence of boundary layer in fluid flow is because of the
surface tension
fluid density
fluid viscosity
gravity forces

Answer 10

C

Question 11

In case of laminar flow of fluid through a circular pipe, the

A. shear stress over the cross-section is proportional to the distance from the surface of the pipe.
B. surface of velocity distribution is a paraboloid of revolution, whose volume equals half the volume of circumscribing cylinder.
C. velocity profile varies hyperbolically and the shear stress remains constant over the cross-section.
D.average flow occurs at a radial distance of 0.5 r from the centre of the pipe (r = pipe radius).

Answer 11

B

Question 12

Which of the following facilitates close control of flow of fluids ?
Gate valve
Globe valve
Butterfly valve
Check valve

Answer 12

B

Question 13

Fanning friction factor equation applies to the __________ fluid flow.
non-isothermal condition of
compressible
both (a) and (b)
neither (a) nor (b)

Answer 13

D

Question 14

For an ideal fluid flow, Reynolds number is
2100
100
0
∞

Answer 14

D

Question 15

Stoke’s equation is valid in the Reynolds number range
0.01 to 0.1
0.1 to 2
2 to 10
10 to 100

Answer 15

A

Question 16

When a fluid flows over a solid surface, the
velocity is uniform at any cross-section.
velocity gradient is zero at the solid surface.
resistance between the surface & the fluid is lesser as compared to that between the fluid layers themselves.
velocity is not zero at the solid surface.

Answer 16

B

Question 17

Pick out the wrong statement about cavitation.
Sudden reduction of pressure in a fluid flow system caused by flow separation, vortex formation or abrupt closing of valve leads to cavitation.
Cavitation may be caused due to boiling of liquid by decreasing the pressure resulting in formation & collapse of vapor cavities.
Cavitation begins at higher static pressure and lower velocity in larger diameter pipelines resulting in audible noise.
Large scale cavitation can not damage pipeline, restrict fluid flow and damage steam turbine blades.

Answer 17

D

Question 18

The maximum delivery pressure of a reciprocating compressor may be about __________ kg/cm2.
1000
2000
3000
4000

Answer 18

D

Question 19

The velocity for subsonic flow in a pipeline
increases in the downstream direction.
is constant.
decreases in the downstream direction.
is independent of the area of flow.

Answer 19

A

Question 20

Permanent pressure loss in a well designed venturimeter is about __________ percent of the venturi differential.
1
10
30
50

Answer 20

B

Question 21

The ratio of pressure forces to inertial forces is called the __________ number.
Froude
Euler
Reynold
Mach

Answer 21

B

Question 22

Bernoulli’s equation for fluid flow is derived following certain assumptions. Out of the assumptions listed below, which set of assumptions is used in derivation of Bernoulli’s equation ?
A. Fluid flow is frictionless & irrotational.
B. Fluid flow is steady.
C. Fluid flow is uniform & turbulent.
D. Fluid is compressible.
E. Fluid is incompressible.
A, C, D
B, D, E
A, B, E
A, D, E

Answer 22

C

Question 23

Cavitation in a centrifugal pump results from
high discharge pressure
low barometric pressure
high discharge velocity
high discharge rate

Answer 23

B

Question 24

For turbulent flow of newtonion fluid in a circular cross-section pipe, the ratio of maximum to average fluid velocity is
0.5
1
0.66
< 0.5

Answer 24

B

Question 25

For flow through a venturi at a particular discharge, the correct relationships among heads at points X, Y, and Z are h1 > h2 < h3 h1 > h2 > h3 h2 < h1 < h3 h1 < h2 < h3

Answer 25

A

Question 26

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 102π 5π/2 52π 5π/2

Answer 26

B

Question 27

he time of oscillation of a floating body is longer, if metacentric height is increased. independent of the metacentric height. dependent on the buoyant forces only. none of these.

Answer 27

D

Question 28

What is the value of Fanning friction factor f ' for smooth pipe at NRe = 106 approximately ? 0.003 0.01 0.1 0.3

Answer 28

A

Question 29

The hydraulic radius for flow in a rectangular duct of cross-sectional dimension H, W is

Answer 29

B

Question 30

In magnetic flow meters, voltage generation is due to the motion of conducting fluid through an externally generated uniform field. proportional to the fluid velocity. both (a) and (b). neither (a) nor (b).

Answer 30

C

Question 31

Air vessel provided in a reciprocating pump is for increasing the acceleration head. making the friction in pipe uniform. decreasing the acceleration head. none of these.

Answer 31

B

Question 32

A hydraulic accumulator comprises of a storage device and a control valve. a cylinder and a plunger. two pistons and two cylinders. a storage tank and a ram pump.

Answer 32

B

Question 33

Bernoulli's equation for steady, frictionless, continuous flow states that the __________ at all sections is same. total pressure total energy velocity head none of these

Answer 33

B

Question 34

A tube is specified by its thickness only outer diameter only thickness & outer diameter both inner diameter

Answer 34

C

Question 35

Uniform fluid flow occurs, when the derivative of the flow variables satisfy the following condition.

Answer 35

C

Question 36

Prandtl mixing length is applicable to laminar flow problems. a universal constant. zero at the pipe wall. none of these.

Answer 36

C

Question 37

The hydraulic diameter of an annulus of inner and outer radii Ri and Ro respectively is 4(Ro-Ri) Ro-Ri 2(Ro-Ri) Ro + Ri

Answer 37

C

Question 38

Ratio of inertial forces to surface tension forces is called the __________ number. Euler Froude Mach Weber

Answer 38

D

Question 39

In open channel flow in a rectangular channel, the ratio between the critical depth and the initial depth, when a hydraulic jump occurs is 0.5 0.84 1.84 1.25

Answer 39

C

Question 40

The ratio of inertial forces to viscous forces is called the __________ number. Weber Mach Froude Reynold

Answer 40

D

Question 41

Enamels and paints are generally __________ fluid. reheopectic pseudo-plastic thixotropic dilatant

Answer 41

B

Question 42

With the increase in depth, the hydrostatic pressure in an unaccelerated incompressible fluid (in a constant gravitational field) decreases. increases linearly. increases exponentially. remains constant.

Answer 42

B

Question 43

Flow measurement in an open channel is done by a/an venturimeter orificemeter weir rotameter

Answer 43

C

Question 44

Newton's law of viscosity relates the shear stress and velocity. velocity gradient and pressure intensity. shear stress and rate of angular deformation in a fluid. pressure gradient and rate of angular deformation.

Answer 44

C

Question 45

Applicability of Bernoulli's equation is limited to a/an __________ fluid, that does not exchange shaft work with the surroundings. incompressible non-viscous both (a) and (b) neither (a) nor (b)

Answer 45

C

Question 46

The equivalent diameter for fluid flow through square cross section channel of side 'x', for pressure drop calculation purpose is given by 4x 2x x SQRT x

Answer 46

C

Question 47

Hydraulic radius of 6" x 12" cross-section, is __________ inches. 2 0.5 1.5 none of these

Answer 47

A

Question 48

Baffles in mixing tanks are provided to reduce swirling and vortex formation. increase the structural strength of the tank. aid in rotational flow. none of these

Answer 48

A

Question 49

Which of the following equations is valid for laminar flow of a fluid through packed bed? Fanning equation Kozney - Karman equation Hagen-Poiseuille equation Blake-Plummer equation

Answer 49

B

Question 50

A pipe has a porous section of length L as shown in the figure. Velocity at the start of this section of V0. If fluid leaks into the pipe through the porous section at a volumetric rate per unit area q(x/L)2, what will be axial velocity in the pipe at any x ? Assume incompressible one dimensional flow i.e., no gradients in the radial direction.

Answer 50

D

Question 51

Forces acting on a particle settling in fluid are __________ forces. gravitational & buoyant. centrifugal & drag. gravitational or centrifugal buoyant drag. external, drag & viscous.

Answer 51

C

Question 52

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.

Answer 52

A

Question 53

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

Answer 53

A

Question 54

Specific speed of a centrifugal pump depends upon the __________ head. suction delivery manometric none of these

Answer 54

D

Question 55

Navier-Stokes equation is useful in the analysis of __________ fluid flow problems. non-viscous viscous turbulent rotational

Answer 55

B

Question 56

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

Answer 56

d

Question 57

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

Answer 57

D

Question 58

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.

Answer 58

B

Question 59

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

Answer 59

A

Question 60

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

Answer 60

B

Question 61

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

Answer 61

D

Question 62

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

Answer 62

C

Question 63

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).

Answer 63

D

Question 64

wo liquids manometer is used for measuring small pressure differences in liquids gases mixture of hydrocarbons none of these

Answer 64

B

Question 65

A piezometer provided in the pipe measures friction factor static pressure dynamic pressure none of these

Answer 65

B

Question 66

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.

Answer 66

B

Question 67

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.

Answer 67

C

Question 68

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).

Answer 68

D

Question 69

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

Answer 69

C

Question 70

Boiler feed water pump is usually a __________ pump. reciprocating gear multistage centrifugal diaphragm

Answer 70

C

Question 71

Viscosity of a liquid decreases __________ with rise in temperature. exponentially linearly logarithmically none of these

Answer 71

C

Question 72

Viscosity of a liquid decreases __________ with rise in temperature. exponentially linearly logarithmically none of these

Answer 72

A

Question 73

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.

Answer 73

A

Question 74

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.

Answer 74

B

Question 75

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

Answer 75

C

Question 76

Major loss in sudden contraction in pipe flow is due to boundary friction. flow contraction. expansion of flow after sudden contraction. none of these.

Answer 76

B

Question 77

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

Answer 77

B

Question 78

The ratio of actual discharge to theoretical discharge through an orifice is equal to Cc . Cv Cc . Cd Cv . Cd Cd/Cv

Answer 78

A

Question 79

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

Answer 79

D

Question 80

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

Answer 80

A

Question 81

Which of the following is a Newtonian fluid? Rubber latex Sewage sludge Quicksand Non-colloidal solution

Answer 81

D

Question 82

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

Answer 82

C

Question 83

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

Answer 83

B

Question 84

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.

Answer 84

A

Question 85

nit of mass velocity is kg/hr kg/m2. hr kg/m2 kg/m3. hr

Answer 85

B

Question 86

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

Answer 86

A

Question 87

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

Answer 87

B

Question 88

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

Answer 88

B

Question 89

Low specific speed of a pump implies that, it is a/an __________ pump. axial flow centrifugal mixed flow none of these

Answer 89

B

Question 90

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

Answer 90

B

Question 91

For pumping slurry, one can use a __________ pump. reciprocating diaphargm centrifugal pneumatic

Answer 91

B

Question 92

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.

Answer 92

A

Question 93

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 -D2

Answer 93

D

Question 94

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.

Answer 94

C

Question 95

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

Answer 95

A

Question 96

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).

Answer 96

D

Question 97

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.

Answer 97

A

Question 98

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

Answer 98

A

Question 99

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.

Answer 99

A

Question 100

Fluid flow through a packed bed is represented by the __________ equation. Fanning's Ergun's Hagen-Poiseuille's none of these

Answer 100

B