Q.1

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.
Q.2

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.
Q.3

Assuming flow to be laminar, if the diameter of the pipe is halved, then the pressure drop will

  • increase
  • decrease
  • remain same
  • be quadrupled
Q.4

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
Q.5

Centrifugal compressors compared to reciprocating compressors

  • require less space.
  • have quieter operation.
  • have lower operating costs.
  • all (a), (b) and (c).
Q.6

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
Q.7

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
Q.8

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
Q.9

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.
Q.10

The Reynolds number for an ideal fluid flow is

  • 4
  • 2100-4000
  • 4000
  • ∞
Q.11

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.
Q.12

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.
Q.13

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.
Q.14

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

  • inner
  • outer
  • approximate
  • none of these
Q.15

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.
Q.16

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
  • x
Q.17

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.
Q.18

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
Q.19

Slugging occurs in a fluidised bed, if the bed is

  • narrow
  • deep
  • both (a) & (b)
  • neither (a) nor (b)
Q.20

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.
Q.21

Nominal Pipe Size (NPS) of a pipe less thaninches in diameter indicates its

  • inner diameter
  • outer diameter
  • thickness
  • neither inner nor outer diameter
Q.22

The pressure head on sudden contraction in a horizontal pipe is converted into the __________ head.

  • elevation
  • velocity
  • both (a) & (b)
  • neither (a) nor (b)
Q.23

A stream tube is that, which has __________ cross-section entirely bounded by stream lines.

  • a circular
  • any convenient
  • a small
  • a large
Q.24

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).
Q.25

For pumping slurry, one can use a __________ pump.

  • reciprocating
  • diaphargm
  • centrifugal
  • pneumatic
Q.26

The ratio of maximum to average velocity in case of streamline flow between parallel plates is

  • 1
  • 1.5
  • 2
  • 2.5
Q.27

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
Q.28

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.
Q.29

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
Q.30

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.
Q.31

A fluid is pumped at the rate oflb/sec to a height offt. The horse power required is __________ hp.

  • 1
  • 10/55
  • 5.5
  • 1/55
Q.32

Hydraulic radius ofxcross-section, is __________ inches.

  • 2
  • 0.5
  • 1.5
  • none of these
Q.33

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
Q.34

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.
Q.35

__________ 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
Q.36

Enamels and paints are generally __________ fluid.

  • reheopectic
  • pseudo-plastic
  • thixotropic
  • dilatant
Q.37

I.D. of 1/schedulepipe is 0.364". I.D. of a 1/schedulepipe would be __________ inch

  • 4.728
  • 0.5
  • 0.622
  • 0.474
Q.38

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).
Q.39

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.
Q.40

For the production of very high vacuum, a __________ pump is normally used.

  • diffusion
  • centrifugal
  • jet ejector
  • piston
Q.41

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.
Q.42

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

  • gravity
  • inertial
  • viscous
  • none of these
Q.43

The velocity distribution in direction normal to the direction of flow in plane Poiseuille flow is

  • hyperbolic
  • parabolic
  • linear
  • none of these
Q.44

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

  • 1000
  • 2000
  • 3000
  • 4000
Q.45

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
Q.46

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
Q.47

One stoke (unit of kinematic viscosity) is equivalent to

  • 1 cm2/second
  • 1 m2/second
  • 1 gm/cm. second
  • 1 kg . m/second
Q.48

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.
Q.49

Flow measurement in an open channel is done by a/an

  • venturimeter
  • orificemeter
  • weir
  • rotameter
Q.50

Two liquids manometer is used for measuring small pressure differences in

  • liquids
  • gases
  • mixture of hydrocarbons
  • none of these
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