590+ Hydraulics and Fluid Mechanics Solved MCQs

These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Civil Engineering .

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351.	When a body is placed over a liquid, it will sink down if
A.	gravitational force is equal to the upthrust of the liquid
B.	gravitational force is les than the upthrust of the liquid
C.	gravitational force is more than the upthrust of the liquid
D.	none of the above
Answer» C. gravitational force is more than the upthrust of the liquid

discuss

352.	The pressure of air
A.	does not change
B.	decreases
C.	increases
Answer» B. decreases

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353.	If the coefficient of discharge is 0.6, then the discharge over a right angled notch is
A.	0.417 H5/2
B.	1.417 H5/2
C.	4.171 H5/2
D.	7.141 H5/2
Answer» B. 1.417 H5/2

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354.	The velocity corresponding to Reynold number of 2000 is called
A.	sub-sonic velocity
B.	super-sonic velocity
C.	lower critical velocity
D.	higher critical velocity
Answer» C. lower critical velocity

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355.	The unit of surface tension is
A.	N / m
B.	N / m2
C.	N / m3
D.	N - m
Answer» A. N / m

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356.	The velocity at which the turbulent flow starts is known as higher critical velocity.
A.	Yes
B.	No
Answer» A. Yes

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357.	In order to measure the flow with a venturimeter, it is installed in
A.	horizontal line
B.	inclined line with flow upwards
C.	inclined line with flow downwards
D.	any direction and in any location
Answer» D. any direction and in any location

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358.	The shear stress-strain graph for a non-newtonian fluid is a curve.
A.	Correct
B.	Incorrect
Answer» A. Correct

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359.	The velocity of liquid flowing through an orifice varies with the available head of the liquid.
A.	Agree
B.	Disagree
Answer» A. Agree

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360.	The D-Alembert's principle is used for changing the dynamic equilibrium of a fluid mass, into a static equilibrium.
A.	Agree
B.	Disagree
Answer» A. Agree

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361.	When the Mach number is between
A.	1 and 2.5
B.	2.5 and 4
C.	4 and 6
D.	1 and 6
Answer» D. 1 and 6

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362.	The hoss of hed due to an obstruction in a pipe is twice the loss of head at its entrance.
A.	Agree
B.	Disagree
Answer» A. Agree

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363.	The dynamic viscosity of gases
A.	remain unaffected
B.	increases
C.	decreases
Answer» B. increases

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364.	A fluid whose viscosity does not change with the rate of deformation or shear strain is known as
A.	real fluid
B.	ideal fluid
C.	newtonian fluid
D.	non-newtonian fluid
Answer» C. newtonian fluid

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365.	If a body floating in a liquid returns back to its original position, when given a small angular displacement, the body is said to be in
A.	neutral equilibrium
B.	stable equilibrium
C.	unstable equilibrium
D.	none of these
Answer» B. stable equilibrium

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366.	The property of a liquid which controls its rate of flow is called viscosity.
A.	True
B.	False
Answer» A. True

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367.	Reyold's number is the ratio of the inertia force to the
A.	surface tension force
B.	viscous force
C.	gravity force
D.	elastic force
Answer» B. viscous force

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368.	When the end contractions of the weir are suppressed, then number of end contractions (n) are taken as zero
A.	Agree
B.	Disagree
Answer» A. Agree

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369.	The specific gravity has no units.
A.	Agree
B.	Disagree
Answer» A. Agree

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370.	A vertical wall is subjected to a pressure due to one kind of liquid, on one of its sides. Which of the following statement is correct?
A.	The pressure on the wall at the liquid level is minimum.
B.	The pressure on the bottom of the wall is maximum
C.	The pressure on the wall at the liquid level is zero, and on the bottom of the wall is maximum
D.	The pressure on the bottom of the wall is zero.
Answer» C. The pressure on the wall at the liquid level is zero, and on the bottom of the wall is maximum

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371.	The stability of a dam is checked for
A.	tension at the base
B.	overturning of the wall or dam
C.	sliding of the wall or dam
D.	all of these
Answer» D. all of these

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372.	The centre of buoyancy is the centre of area of the immersed body.
A.	Correct
B.	Incorrect
Answer» A. Correct

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373.	The shear stress between the two liquid layers is
A.	directly
B.	indirectly
Answer» B. indirectly

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374.	The kinematic viscosity of an oil (in stokes) whose specific gravity is 0.95 and viscosity 0.011 poise, is
A.	0.0116 stoke
B.	0.116 stoke
C.	0.0611 stoke
D.	0.611 stoke
Answer» A. 0.0116 stoke

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375.	A nozzle placed at the end of a water pipe line discharges water at a
A.	low pressure
B.	high pressure
C.	low velocity
D.	high velocity
Answer» D. high velocity

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376.	Bernoulli's equation is applied to
A.	venturimeter
B.	orifice meter
C.	pitot tube
D.	all of these
Answer» D. all of these

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377.	The flow in a pipe is laminar, when Reynold number is less than 2000.
A.	True
B.	False
Answer» A. True

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378.	Select the wrong statement
A.	Weber's number is the ratio of inertia force to elastic force.
B.	Weber's number is the ratio of gravity force to surface tension force.
C.	Weber's number is the ratio of viscous force to pressure force.
D.	Weber's number is the ratio of inertia force to surface tension force.
Answer» D. Weber's number is the ratio of inertia force to surface tension force.

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379.	A vessel of 4 m3 contains an oil which weighs 30 kN. The specific weight of the oil is
A.	4.5 kN / m3
B.	6 kN / m3
C.	7.5 kN / m3
D.	10 kN / m3
Answer» C. 7.5 kN / m3

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380.	The quantity of a liquid flowing per second through a section of a pipe or a channel is called discharge and is measured in cumecs (m3/s).
A.	True
B.	False
Answer» A. True

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381.	Water is
A.	a compressible
B.	an incompressible
Answer» B. an incompressible

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382.	The specific weight of sea water is
A.	same as
B.	less than
C.	more than
Answer» C. more than

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383.	The separation of flow occurs when the hydrodynamic boundary layer thickness is reduced to zero.
A.	Agree
B.	Disagree
Answer» A. Agree

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384.	The specific weight of compressible fluids does not remain constant.
A.	True
B.	False
Answer» A. True

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385.	An internal mouthpiece is said to be runing
A.	free
B.	partially
C.	full
Answer» C. full

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386.	Turbulent flow takes place at high velocities.
A.	Agree
B.	Disagree
Answer» A. Agree

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387.	The property of a liquid which offers resistance to the movement of one layer of liquid over another adjacent layer of liquid, is called
A.	surface tension
B.	compressibility
C.	capillarity
D.	viscosity
Answer» D. viscosity

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388.	The ratio of the inertia force to the surface tension force is called Weber's number.
A.	Correct
B.	Incorrect
Answer» A. Correct

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389.	A venturiflume is used to measure
A.	pressure of liquid
B.	discharge of liquid
C.	pressure difference between two points in a channel
D.	pressure difference between two points in a pipe
Answer» B. discharge of liquid

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390.	A fluid whose viscosity changes with the rate of deformation or shear strain is known as non-newtonian fluid.
A.	True
B.	False
Answer» A. True

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391.	Falling drops of water become spheres due to the property of
A.	surface tension of water
B.	compressibility of water
C.	capillarity of water
D.	viscosity of water
Answer» A. surface tension of water

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392.	A flow in which the quantity of liquid flowing per second is not constant, is called
A.	streamline flow
B.	turbulent flow
C.	steady flow
D.	unsteady flow
Answer» D. unsteady flow

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393.	A flow whose streamline is represented by a straight line, is called
A.	one
B.	two
C.	three
D.	four
Answer» A. one

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394.	The rise of liquid along the walls of a revolving cylinder about the initial level is
A.	same as
B.	less than
C.	more than
Answer» A. same as

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395.	A nirform body 3 m long, 2 m wide and 1 m deep floats in water. If the depth of immersion is 0.6 m, then the weight of the body is
A.	3.53 kN
B.	33.5 kN
C.	35.3 kN
D.	none of these
Answer» C. 35.3 kN

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396.	A point, in a compressible flow where the velocity of fluid is zero, is called
A.	critical point
B.	vena contracta
C.	stagnation point
D.	none of these
Answer» C. stagnation point

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397.	The coefficient of viscosity may be determined by
A.	capillary tube method
B.	orifice type viscometer
C.	rotating cylinder method
D.	all of these
Answer» D. all of these

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398.	Coefficient of contraction is the ratio of
A.	actual velocity of jet at vena contracta to the theoretical velocity
B.	loss of head in the orifice to the head of water available at the exit of the orifice
C.	actual discharge through an orifice to the theoretical discharge
D.	area of jet at vena contracta to the area of orifice
Answer» D. area of jet at vena contracta to the area of orifice

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399.	In an external or internal mouthpiece, the absolute pressure head at vena contracta is zero when atmospheric pressure head is 10.3 m of water.
A.	Correct
B.	Incorrect
Answer» A. Correct

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400.	When the pressure intensity at a point is less than the local atmospheric pressure, then the difference of these two pressures is called vacuum pressure.
A.	Agree
B.	Disagree
Answer» A. Agree

discuss

590+ Hydraulics and Fluid Mechanics Solved MCQs

When a body is placed over a liquid, it will sink down if

The pressure of air

If the coefficient of discharge is 0.6, then the discharge over a right angled notch is

The velocity corresponding to Reynold number of 2000 is called

The unit of surface tension is

The velocity at which the turbulent flow starts is known as higher critical velocity.

In order to measure the flow with a venturimeter, it is installed in

The shear stress-strain graph for a non-newtonian fluid is a curve.

The velocity of liquid flowing through an orifice varies with the available head of the liquid.

The D-Alembert's principle is used for changing the dynamic equilibrium of a fluid mass, into a static equilibrium.

When the Mach number is between

The hoss of hed due to an obstruction in a pipe is twice the loss of head at its entrance.

The dynamic viscosity of gases

A fluid whose viscosity does not change with the rate of deformation or shear strain is known as

If a body floating in a liquid returns back to its original position, when given a small angular displacement, the body is said to be in

The property of a liquid which controls its rate of flow is called viscosity.

Reyold's number is the ratio of the inertia force to the

When the end contractions of the weir are suppressed, then number of end contractions (n) are taken as zero

The specific gravity has no units.

A vertical wall is subjected to a pressure due to one kind of liquid, on one of its sides. Which of the following statement is correct?

The stability of a dam is checked for

The centre of buoyancy is the centre of area of the immersed body.

The shear stress between the two liquid layers is

The kinematic viscosity of an oil (in stokes) whose specific gravity is 0.95 and viscosity 0.011 poise, is

A nozzle placed at the end of a water pipe line discharges water at a

Bernoulli's equation is applied to

The flow in a pipe is laminar, when Reynold number is less than 2000.

Select the wrong statement

A vessel of 4 m3 contains an oil which weighs 30 kN. The specific weight of the oil is

The quantity of a liquid flowing per second through a section of a pipe or a channel is called discharge and is measured in cumecs (m3/s).

Water is

The specific weight of sea water is

The separation of flow occurs when the hydrodynamic boundary layer thickness is reduced to zero.

The specific weight of compressible fluids does not remain constant.

An internal mouthpiece is said to be runing

Turbulent flow takes place at high velocities.

The property of a liquid which offers resistance to the movement of one layer of liquid over another adjacent layer of liquid, is called

The ratio of the inertia force to the surface tension force is called Weber's number.

A venturiflume is used to measure

A fluid whose viscosity changes with the rate of deformation or shear strain is known as non-newtonian fluid.

Falling drops of water become spheres due to the property of

A flow in which the quantity of liquid flowing per second is not constant, is called

A flow whose streamline is represented by a straight line, is called

The rise of liquid along the walls of a revolving cylinder about the initial level is

A nirform body 3 m long, 2 m wide and 1 m deep floats in water. If the depth of immersion is 0.6 m, then the weight of the body is

A point, in a compressible flow where the velocity of fluid is zero, is called

The coefficient of viscosity may be determined by

Coefficient of contraction is the ratio of

In an external or internal mouthpiece, the absolute pressure head at vena contracta is zero when atmospheric pressure head is 10.3 m of water.

When the pressure intensity at a point is less than the local atmospheric pressure, then the difference of these two pressures is called vacuum pressure.