Q.1

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.

  • NPSH required.
  • BHP required by the pump.
  • head of the liquid pumped.
  • all (a), (b) and (c).
Q.2

Which of the following is an undesirable property of a manometric liquid ?

  • Non-sticky & non-corrosive nature.
  • High vapour pressure.
  • Low viscosity & surface tension.
  • Low co-efficient of thermal expansion.
Q.3

Which of the following options will facilitate the achievement of a very high head (saymetres) in case of a centrifugal pump?

  • Increasing the impeller speed and the volute area.
  • Increasing the number of vanes in the impeller.
  • Mounting of two or more impellers in series on a single shaft.
  • Either of (a), (b) or (c).
Q.4

N2Re/NFr is called the __________ number.

  • Brinkman
  • Galileo
  • Archimedes
  • Euler
Q.5

The ratio of hydrodynamic boundary layer to thermal boundary layer thickness in case of liquid metals is

  • < 1
  • 1
  • > 1
  • 2
Q.6

A venturimeter can not be used for the direct measurement of

  • datum difference in the stretch of pipeflow
  • pressure difference in the flow throughpipeline.
  • friction loss in pipe flow.
  • all (a), (b) and (c).
Q.7

A centrifugal pump is called a turbine pump, if it is having a

  • turbine type impeller.
  • vaned diffusion casing.
  • rotating vaned volute.
  • none of these.
Q.8

When the water is warm, the height to which it can be lifted by a pump

  • decreases due to reduced viscosity.
  • decreases due to reduced vapour pressure.
  • increases due to increased vapour pressure
  • decreases due to increased frictional resistance.
Q.9

Check valves are used

  • at high pressure.
  • in bends.
  • for controlling water flow.
  • for unidirectional flow.
Q.10

A mercury (specific gravity = 13.manometer connected across an orificemeter fitted in a pipe shows a manometer reading of 2 cms. If the manometer liquid is changed to carbon tetrachloride (specific gravity = 1.6), then for the same flow rate of water the new manometer reading will be __________ cms.

  • 17
  • 42
  • 84
  • 1.8
Q.11

Where does the maximum stress occur in case of laminar flow of incompressible fluid in a closed conduit of diameter 'd'?

  • At the centre
  • At d/4 from the wall
  • At the wall
  • At d/8 from the wall
Q.12

In a fluidised bed reactor

  • temperature gradients are very high.
  • temperature is more or less uniform.
  • hot spots are formed.
  • segregation of the solids occurs.
Q.13

Experimental study of laminar fluid flow through a circular tube was conducted by

  • Reynolds
  • Hagen and Poiseuille
  • Pascal
  • Blake-Plummer
Q.14

The uniformity of a gas fluidised bed depends upon the __________ of the solid particles.

  • size
  • surface properties
  • both (a) and (b)
  • neither (a) nor (b)
Q.15

Fluid flow at increasing rate through a diverging pipe is an example of __________ flow.

  • steady uniform
  • non-steady uniform
  • steady non-uniform
  • non-steady non-uniform
Q.16

Theoretical head developed by a centrifugal pump does not depend upon the __________ the impeller.

  • radius of
  • speed of
  • fluid velocity leaving
  • none of these
Q.17

If more than two branches of pipes are to be connected at the same point, then use a/an

  • elbow
  • union
  • tee
  • none of these.
Q.18

Reciprocating pumps are not able to compete with the centrifugal pump for industrial use, mainly because these pumps have

  • very low speeds.
  • smaller discharge.
  • higher capital &maintenance cost.
  • high vibrations.
Q.19

Turbulent flow generally occurs for cases involving

  • highly viscous fluid
  • very narrow passages
  • very slow motion
  • none of these
Q.20

Reynolds number is the ratio of

  • viscous forces to gravity forces.
  • inertial forces to viscous forces.
  • viscous forces to inertial forces.
  • inertial forces to gravity forces.
Q.21

A mercury (specific gravity = 13.manometer connected across an orificemeter fitted in a pipe shows a manometer reading of 2 cms. If the manometer liquid is changed to carbon tetrachloride (specific gravity = 1.6), then for the same flow rate of water the new manometer reading will be __________ cms.

  • 17
  • 42
  • 84
  • 1.8
Q.22

An equipotential line is __________ to the velocity vector at every point.

  • normal
  • normal
  • tangential
  • none of these
Q.23

In area meter (e.g., rotameter), with increase in the fluid flow rate, the

  • pressure drop increases linearly.
  • pressure drop is almost constant.
  • area through which fluid flows does not vary.
  • none of these.
Q.24

Drag co-efficient in hindered settling is __________ that in free settling.

  • less than
  • equal to
  • not necessarily greater than
  • always greater than
Q.25

In case of end to end connection of two or more pipes in series, the __________ each pipe.

  • same rate of flow passes through
  • head loss is same through
  • rate of flow in each pipe is proportional to the length of
  • total flow rate is the sum of flow rate in
Q.26

The general relationship between speed N, head H, power P and discharge Q for a centrifugal pump is

  • Q∝N : H∝N2 : P∝N3
  • Q∝N2 : H∝N3 : P∝N
  • Q∝N : H∝N3 : P∝N2
  • Q∝N3 : H∝N : P∝N2
Q.27

The peripherial velocity at inlet of a centrifugal pump having inlet diameter ofcms and rotating atrpm is __________ m/sec.

  • 1.8
  • 12.4
  • 186.2
  • 736.4
Q.28

A double acting reciprocating pump compared to a single acting pump (of almost same size working under same pressure levels) would give almost double

  • head
  • discharge
  • efficiency
  • none of these
Q.29

Drag co-efficient in hindered settling is __________ that in free settling.

  • less than
  • equal to
  • not necessarily greater than
  • always greater than
Q.30

Pipes having diameterinches or more are designated by their

  • outside diameter
  • inside diameter
  • schedule number
  • none of these
Q.31

The flow of a liquid through tapering pipe at a constant rate is an example of __________ flow.

  • steady uniform
  • steady non uniform
  • unsteady uniform
  • unsteady non uniform
Q.32

The most economical flow control valve for use with large diameter pipes is a

  • butterfly valve
  • globe valve
  • needle valve
  • none of these
Q.33

The temperature in isentropic flow

  • does not depend on Mach number.
  • depends on Mach number only.
  • cannot drop and then increase again downstream.
  • none of these.
Q.34

In case of a centrifugal pump, the ratio of total delivered pressure to pressure developed with the impeller is called the __________ efficiency.

  • manometric
  • mechanical
  • volumetric
  • overall
Q.35

Which is the correct relationship for a centrifugal pump ? (where, D = Impeller diameter, inches H = Head developed, ft of liquid pumped N = Speed of pump, rpm)

  • D = 1840 H0.5/N
  • D = 1840 N/H0.5
  • H = 1840 D0.5/N
  • D = 1840 H/N
Q.36

Lower BWG means __________ of the tube.

  • lower thickness
  • lower cross-section
  • outer diameter
  • inner diameter
Q.37

Liquid delivery by centrifugal pump starts, only when the head developed by it is equal to the __________ head.

  • manometric
  • total
  • static
  • friction
Q.38

The frictional resistance in laminar flow does not depend on the

  • area of surface in contact.
  • flow velocity.
  • fluid temperature.
  • pressure of flow.
Q.39

In case of a centrifugal pump, the ratio of total delivered pressure to pressure developed with the impeller is called the __________ efficiency.

  • manometric
  • mechanical
  • volumetric
  • overall
Q.40

As the velocity V and thus the Reynolds number of a flow past a sphere increases from very low value, the drag force for Re << 1

  • increases linearly with V.
  • decreases linearly with V.
  • decreases as V2.
  • none of these.
Q.41

Efficiency of power transmission (η) through a circular pipe is given by (ht - hf)/ht, which has a maximum value of __________ percent.

  • 33:3
  • 50
  • 66.6
  • 88.8
Q.42

Which of the following equations applies to the fluid flow through a packed bed for very large Reynolds number ?

  • Fanning equation
  • Blake-Pllummer equation
  • Hagen-Poiseulle equation
  • Kozney-Karman equation
Q.43

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 ?

  • 0.5
  • 0.67
  • 1
  • 2
Q.44

Laminar flow is characterised by the nonexistence of

  • pressure fluctuation.
  • eddies.
  • deviating velocities.
  • all (a), (b)&(c).
Q.45

Which of the following is used for very accurate measurement of flow of gas at low velocity ?

  • Pitot tube
  • Rotameter
  • Segmental orificemeter
  • Hot wire annemometer
Q.46

Viscosity of water at 40°C lies in the range of

  • 1 x 10-3 to 2 x 10-3 kg/m.s
  • 0.5 x 10-3 to 1 x 10-3 kg/m.s
  • 1 to 2 kg/m.s
  • 0.5 to 1 kg/m.s
Q.47

Pick out the correct statement pertaining to transition/ entrance length in fluid flow.

  • The length of entrance region of pipe, in which full development of fluid flow takes place such that velocity profile does not change downstream, is called the transition length.
  • Transition length for laminar flow of Newtonion fluids in a pipe of diameter 'd' is equal to 0.05. D.NRe.
  • Transition length for turbulent flow of Newtonion fluids in a smooth pipe of diameter 'd' is equal to 50 D.
  • all (a), (b) and (c).
Q.48

Each term in Bernaulli's equation represents the __________ of the fluid.

  • energy per unit mass
  • energy per unit weight
  • force per unit mass
  • none of these
Q.49

Which of the following is used for very accurate measurement of flow of gas at low velocity ?

  • Pitot tube
  • Rotameter
  • Segmental orificemeter
  • Hot wire annemometer
Q.50

The discharge through a venturimeter depends upon

  • pressure drop only.
  • its orientation.
  • co-efficient of contraction only.
  • none of these.
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