the resultant force on a body due to the fluid surrounding it

resultant force acting on a floating body

equal to the volume of liquid displaced

force necessary to keep a body in equilibrium

frictionless and incompressible

one which obeys Newton’s law of viscosity

Practice Hydraulics And Fluid Mechanics Multiple Choice Questions Quiz-2

Q.1

Resultant pressure of the liquid in the case of an immersed body acts through

center of gravity
center of pressure
metacentre
center of buoyancy

Q.2

Buoyant force is

resultant force acting on a floating body
equal to the volume of liquid displaced
force necessary to keep a body in equilibrium
the resultant force on a body due to the fluid surrounding it

Q.3

An ideal fluid is

one which obeys Newton’s law of viscosity
frictionless and incompressible
very viscous
frictionless and compressible

Q.4

In which of the following the friction drag is generally larger than pressure drag?

a circular disc or plate held normal to flow
a sphere
a cylinder
an airfoil

Q.5

A bucket of water is hanging from a spring balance. An iron piece is suspended into water without touching sides of bucket from another support. The spring balance reading will

increase
decrease
remain same
increase/decrease depending on depth of immersion

Q.6

An open vessel of water is accelerated up an inclined plane. The free water surface will

be horizontal
make an angle in direction of inclination of inclined plane
make an angle in opposite direction to inclination of inclined plane
any one of above is possible

Q.7

The unit of kinematic viscosity is

gm/cm-sec²
dyne-sec/cm²
gm/cm²-sec
cm²/sec

Q.8

An open cubical tank of 2 m side is filled with water. If the tank is rotated with an acceleration such that half of the water spills out, then the acceleration is equal to

g/3
g/2
2g/3
g

Q.9

Fluid is a substance which offers no resistance to change of

pressure
flow
shape
volume

Q.10

Choose the wrong statement.
Alcohol is used in manometer, because

its vapour pressure is low
it provides suitable meniscus for the inclined tube
its density is less
it provides longer length for a given pressure difference

Q.11

Two pipe systems are said to be equivalent when

head loss and discharge are same in two systems
length of pipe and discharge are same in two systems
friction factor and length are same in two systems
length and diameter are same in two systems

Q.12

A perfect gas

has constant viscosity
is incompressible
is of theoretical interest
none of the above.

Q.13

For a floating body to be in stable equilibrium, its metacentre should be

below the center of buoyancy
above the center of buoyancy
between e.g. and center of pressure
above the center of gravity.

Q.14

The resultant of all normal pressures acts

at e.g. of body
at center of pressure
vertically upwards
at metacentre

Q.15

True one-dimensional flow occurs when

the direction and magnitude of the veiocity at all points are identical
the velocity of successive fluid par-ticles, at any point, is the same at suc-cessive periods of time
the magnitude and direction of the velocity do not change from point to point in the fluid
the fluid particles move in plane or parallel planes and the streamline pat-terns are identical in each plane

Q.16

Non uniform flow occurs when

the direction and magnitude of the velocity at all points are identical
the velocity of successive fluid par-ticles, at any point, is the same at suc-cessive periods of time
the fluid particles move in plane or parallel planes and the streamline pat-terns are identical in each plane
velocity, depth, pressure, etc. change from point to point in the fluid flow.

Q.17

Pressure of the order of 10''' torr can be measured by

Bourdon tube
Pirani Gauge
micro-manometer
ionisastion gauge

Q.18

Flow of water in a pipe about 3 meters in diameter can be measured by

orifice plate
venturi
rotameter
pitot tube

Q.19

In a Sutro weir, the discharge is proportional to (where H is head)

H1/2
H3/2
H5/2
H

Q.20

If 850 kg liquid occupies volume of one cubic meter, men 0.85 represents its

specific weight
specific mass
specific gravity
specific density

Q.21

Free surface of a liquid tends to contract to the smallest possible area due to force of

surface tension
viscosity
friction
cohesion

Q.22

The normal stress is same in all directions at a point in a fluid

only when the fluid is frictionless
only when the fluid is incompressible and has zero viscosity
when there is no motion of one fluid layer relative to an adjacent layer
irrespective of the motion of one fluid layer relative to an adjacent layer

Q.23

The surface tension of mercury at normal temperature compared to that of water is

more
less
same
more or less depending on size of glass tube

Q.24

The total pressure force on a plane area is equal to the area multiplied by the intensity of pressure at the centriod, if

the area is horizontal
the area is vertical
the area is inclined
all of the above

Q.25

According to Bernoulli’s equation for steady ideal fluid flow

principle of conservation of mass holds
velocity and pressure are inversely proportional
total energy is constant throughout
the energy is constant along a stream-line but may vary across streamlines

Q.26

When a liquid rotates at a constant angular velocity about a vertical axis as a rigid body, the pressure intensity varies

linearly with radial distance
as the square of the radial distance
inversely as the square of the radial distance
inversely as the radial distance

Q.27

The density of water is 1000 kg/m3 at

0°C
0°K
4°C
20°C

Q.28

To avoid vaporisation in the pipe line, the pipe line over the ridge is laid such that it is not more than

2.4 m above the hydraulic gradient
6.4 m above the hydraulic gradient
10.0 m above the hydraulic gradient
5.0 above the hydraulic gradient

Q.29

The peoperty by virtue of which a liquid opposes relative motion between its different layers is called

surface tension
co-efficient of viscosity
viscosity
osmosis

Q.30

The Prartdtl mixing length is

zero at the pipe wall
maximum at the pipe wall
independent of shear stress
none of the above