365 + Mcqs in Hydraulics And Fluid Mechanics Page 1 McqOptions

1.	A weir is said to be narrow-crested weir, if the width of the crest of the weir is __________ half the height of water above the weir crest.
A.	Equal to
B.	Less than
C.	More than
D.	None of these
Answer» C. More than

Discussion

2.	The property by virtue of which a liquid opposes relative motion between its different layers is called
A.	Surface tension
B.	Coefficient of viscosity
C.	Viscosity
D.	Osmosis
Answer» D. Osmosis

Discussion

3.	In order that flow takes place between two points in a pipeline, the differential pressure between these points must be more than
A.	Frictional force
B.	Viscosity
C.	Surface friction
D.	All of the above
Answer» E.

Discussion

4.	manometers because Alcohol is used in
A.	It has low vapour pressure
B.	It is clearly visible
C.	It has low surface tension
D.	It can provide longer column due to low density
Answer» E.

Discussion

5.	An internal mouthpiece is said to be running free if the length of the mouthpiece is __________ the diameter of the orifice.
A.	Less than twice
B.	More than twice
C.	Less than three times
D.	More than three times
Answer» D. More than three times

Discussion

6.	The region between the separation streamline and the boundary surface of the solid body is known as
A.	Wake
B.	Drag
C.	Lift
D.	Boundary layer
Answer» B. Drag

Discussion

7.	The ratio of specific weight of a liquid to the specific weight of pure water at a standard temperature is called
A.	Density of liquid
B.	Specific gravity of liquid
C.	Compressibility of liquid
D.	Surface tension of liquid
Answer» C. Compressibility of liquid

Discussion

8.	The Metacentric heights of two floating bodies A and B are 1 m and 1.5 m respectively. Select the correct statement.
A.	The bodies A and B have equal stability
B.	The body A is more stable than body B
C.	The body B is more stable than body A
D.	The bodies A and B are unstable
Answer» D. The bodies A and B are unstable

Discussion

9.	The imaginary line drawn in the fluid in such a way that the tangent to any point gives the direction of motion at that point, is known as
A.	Path line
B.	Stream line
C.	Steak line
D.	Potential line
Answer» C. Steak line

Discussion

10.	When a cylindrical vessel containing liquid is revolved about its vertical axis at a constant angular velocity, the pressure
A.	Varies as the square of the radial distance
B.	Increases linearly as its radial distance
C.	Increases as the square of the radial distance
D.	Decreases as the square of the radial distance
Answer» B. Increases linearly as its radial distance

Discussion

11.	An odd shaped body weighing 7.5 kg and occupying 0.01 m3 volume will be completely submerged in a fluid having specific gravity of
A.	1
B.	1.2
C.	0.8
D.	0.75
Answer» E.

Discussion

12.	The shear stress between the two liquid layers is __________ proportional to the distance between two layers.
A.	Directly
B.	Inversely
C.	Both A and B
D.	None of these
Answer» C. Both A and B

Discussion

13.	According to Chezy's formula, the discharge through an open channel is (where A = Area of flow, C = Chezy's constant, m = Hydraulic mean depth, and i = Uniform slope in bed)
A.	A m i)
B.	C m i)
C.	AC m i)
D.	mi A C)
Answer» D. mi A C)

Discussion

14.	The total energy of each particle at various places in the case of perfect incompressible fluid flowing in continuous stream
A.	Keeps on increasing
B.	Keeps on decreasing
C.	Remain constant
D.	May increase/decrease
Answer» D. May increase/decrease

Discussion

15.	A uniform 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.	33.3 kN
C.	35.3 kN
D.	None of these
Answer» D. None of these

Discussion

16.	Total pressure on a lmxlm gate immersed vertically at a depth of 2 m below the free water surface will be
A.	1000 kg
B.	4000 kg
C.	2000 kg
D.	8000 kg
Answer» B. 4000 kg

Discussion

17.	A piece of wood having weight 5 kg floats in water with 60% of its volume under the liquid. The specific gravity of wood is
A.	0.83
B.	0.6
C.	0.4
D.	0.3
Answer» C. 0.4

Discussion

18.	In an internal mouthpiece, if the jet after contraction does not touch the sides of the mouthpiece, then the mouthpiece is said to be
A.	Running full
B.	Running free
C.	Partially running full
D.	Partially running free
Answer» C. Partially running full

Discussion

19.	The meatcentric height of a ship is 0.6 m and the radius of gyration is 4 m. The time of rolling of a ship is
A.	4.1 s
B.	5.2 s
C.	10.4 s
D.	14.1 s
Answer» D. 14.1 s

Discussion

20.	In a footstep bearing, if the radius of the shaft is doubled, then the torque required to overcome the viscous resistance will be
A.	Double
B.	Four times
C.	Eight times
D.	Sixteen times
Answer» E.

Discussion

21.	The most economical section of a rectangular channel is one which has hydraulic mean depth or hydraulic radius equal to
A.	Half the depth
B.	Half the breadth
C.	Twice the depth
D.	Twice the breadth
Answer» B. Half the breadth

Discussion

22.	The flow in which the velocity vector is identical in magnitude and direction at every point, for any given instant, is known as
A.	One dimensional flow
B.	Uniform flow
C.	Steady flow
D.	Turbulent flow
Answer» C. Steady flow

Discussion

23.	According to Darcy's formula, the loss of head due to friction in the pipe is (where f = Darcy's coefficient, l = Length of pipe, v = Velocity of liquid in pipe, and d = Diameter of pipe)
A.	flv /2gd
B.	flv /gd
C.	3flv /2gd
D.	4flv /2gd
Answer» E.

Discussion

24.	The hydraulic gradient line may be above or below the centre line of the pipe.
A.	True
B.	False
Answer» C.

Discussion

25.	The hydraulic gradient line is always parallel to the centre line of the pipe.
A.	Correct
B.	Incorrect
Answer» C.

Discussion

26.	The formula for discharge over a sharp-crested weir and Ogee weir is same as that of a rectangular weir
A.	Agree
B.	Disagree
Answer» B. Disagree

Discussion

27.	In a sharp-crested weir, the thickness of the weir is kept less than half of the height of water above the crest of the weir.
A.	True
B.	False
Answer» B. False

Discussion

28.	The discharge over a rectangular weir, considering the velocity of approach, is (where H1 = Total height of water above the weir = H + Ha H = Height of water, over the crest of the weir, and Ha = Height of water, due to velocity of approach)
A.	Cd x L2g [H1 - Ha]
B.	Cd x L2g [H13/2 - Ha3/2]
C.	Cd x L2g [H12 - Ha2]
D.	Cd x L2g [H15/2 - Ha5/2]
Answer» C. Cd x L2g [H12 - Ha2]

Discussion

29.	The Cippoletti weir is a __________ weir.
A.	rectangular
B.	triangular
C.	trapezoidal
D.	circular
Answer» D. circular

Discussion

30.	The Francis formula for the discharge over Cippoletti weir is
A.	1.84 LH1/2
B.	1.84 LH
C.	1.84 LH3/2
D.	1.84 LH5/2
Answer» D. 1.84 LH5/2

Discussion

31.	According to Bazin, the coefficient of discharge varies with the height of water over the sill of a weir.
A.	Correct
B.	Incorrect
Answer» B. Incorrect

Discussion

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

Discussion

33.	A weir is usually made of masonry or concrete.
A.	Yes
B.	No
Answer» B. No

Discussion

34.	An error of 1% in measuring head over the crest of the notch (H) will produce an error of __________ in discharge over a triangular notch,
A.	1%
B.	1.5%
C.	2%
D.	2.5%
Answer» E.

Discussion

35.	The difference between the notch and weir is that the notch is of bigger size and the weir is of a smaller size.
A.	Agree
B.	Disagree
Answer» C.

Discussion

36.	An error of 1% in measuring head over the apex of the notch (H) will produce an error of __________ in discharge over a triangular notch.
A.	1%
B.	1.5%
C.	2%
D.	2.5%
Answer» E.

Discussion

37.	A notch is, usually, made of a metallic plate.
A.	Correct
B.	Incorrect
Answer» B. Incorrect

Discussion

38.	In a convergent mouthpiece, the absolute pressure head at vena contracta is the same as that of the atmosphere.
A.	True
B.	False
Answer» B. False

Discussion

39.	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» B. Incorrect

Discussion

40.	When an internal mouthpiece is running full, the discharge through the mouthpiece is twice the discharge when it is running free.
A.	Correct
B.	Incorrect
Answer» C.

Discussion

41.	In an internal mouthpiece, if the jet after contraction expands and fills up the whole mouthpiece, then the mouthpiece is said to be running free.
A.	True
B.	False
Answer» C.

Discussion

42.	The loss of head at exit of a pipe is
A.	[A].
B.	[B].
C.	[C].
D.	[D].
Answer» B. [B].

Discussion

43.	A hemispherical tank of radius (R) containing liquid upto height (H1) has an orifice of cross-sectional area (a) at its bottom. The time required to lower the level of liquid from (H1) to (H2) will be
A.	[A].
B.	[B].
C.	[C].
D.	none of the above
Answer» D. none of the above

Discussion

44.	If the value of coefficient of discharge increases, the discharge through the orifice decreases.
A.	True
B.	False
Answer» C.

Discussion

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

Discussion

46.	If a pitot tube is placed with its nose upstream, downstream or sideways, the reading will be the same in every case.
A.	True
B.	False
Answer» C.

Discussion

47.	The coefficient of discharge is the ratio of theoretical discharge to the actual discharge through an orifice.
A.	True
B.	False
Answer» C.

Discussion

48.	In two dimensional flow, the flow does not take place in a curve.
A.	True
B.	False
Answer» C.

Discussion

49.	All the gases are considered to have compressible flow and all the liquids are considered to have incompressible flow.
A.	Correct
B.	Incorrect
Answer» B. Incorrect

Discussion

50.	A flow through an expanding tube at increasing rate is called unsteady non-uniform flow.
A.	Yes
B.	No
Answer» B. No

Discussion

Explore topic-wise MCQs in Civil Engineering.

A weir is said to be narrow-crested weir, if the width of the crest of the weir is __________ half the height of water above the weir crest.

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

In order that flow takes place between two points in a pipeline, the differential pressure between these points must be more than

manometers because Alcohol is used in

An internal mouthpiece is said to be running free if the length of the mouthpiece is __________ the diameter of the orifice.

The region between the separation streamline and the boundary surface of the solid body is known as

The ratio of specific weight of a liquid to the specific weight of pure water at a standard temperature is called

The Metacentric heights of two floating bodies A and B are 1 m and 1.5 m respectively. Select the correct statement.

The imaginary line drawn in the fluid in such a way that the tangent to any point gives the direction of motion at that point, is known as

When a cylindrical vessel containing liquid is revolved about its vertical axis at a constant angular velocity, the pressure

An odd shaped body weighing 7.5 kg and occupying 0.01 m3 volume will be completely submerged in a fluid having specific gravity of

The shear stress between the two liquid layers is __________ proportional to the distance between two layers.

According to Chezy's formula, the discharge through an open channel is (where A = Area of flow, C = Chezy's constant, m = Hydraulic mean depth, and i = Uniform slope in bed)

The total energy of each particle at various places in the case of perfect incompressible fluid flowing in continuous stream

A uniform 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

Total pressure on a lmxlm gate immersed vertically at a depth of 2 m below the free water surface will be

A piece of wood having weight 5 kg floats in water with 60% of its volume under the liquid. The specific gravity of wood is

In an internal mouthpiece, if the jet after contraction does not touch the sides of the mouthpiece, then the mouthpiece is said to be

The meatcentric height of a ship is 0.6 m and the radius of gyration is 4 m. The time of rolling of a ship is

In a footstep bearing, if the radius of the shaft is doubled, then the torque required to overcome the viscous resistance will be

The most economical section of a rectangular channel is one which has hydraulic mean depth or hydraulic radius equal to

The flow in which the velocity vector is identical in magnitude and direction at every point, for any given instant, is known as

According to Darcy's formula, the loss of head due to friction in the pipe is (where f = Darcy's coefficient, l = Length of pipe, v = Velocity of liquid in pipe, and d = Diameter of pipe)

The hydraulic gradient line may be above or below the centre line of the pipe.

The hydraulic gradient line is always parallel to the centre line of the pipe.

The formula for discharge over a sharp-crested weir and Ogee weir is same as that of a rectangular weir

In a sharp-crested weir, the thickness of the weir is kept less than half of the height of water above the crest of the weir.

The discharge over a rectangular weir, considering the velocity of approach, is (where H1 = Total height of water above the weir = H + Ha H = Height of water, over the crest of the weir, and Ha = Height of water, due to velocity of approach)

The Cippoletti weir is a __________ weir.

The Francis formula for the discharge over Cippoletti weir is

According to Bazin, the coefficient of discharge varies with the height of water over the sill of a weir.

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

A weir is usually made of masonry or concrete.

An error of 1% in measuring head over the crest of the notch (H) will produce an error of __________ in discharge over a triangular notch,

The difference between the notch and weir is that the notch is of bigger size and the weir is of a smaller size.

An error of 1% in measuring head over the apex of the notch (H) will produce an error of __________ in discharge over a triangular notch.

A notch is, usually, made of a metallic plate.

In a convergent mouthpiece, the absolute pressure head at vena contracta is the same as that of the atmosphere.

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 an internal mouthpiece is running full, the discharge through the mouthpiece is twice the discharge when it is running free.

In an internal mouthpiece, if the jet after contraction expands and fills up the whole mouthpiece, then the mouthpiece is said to be running free.

The loss of head at exit of a pipe is

A hemispherical tank of radius (R) containing liquid upto height (H1) has an orifice of cross-sectional area (a) at its bottom. The time required to lower the level of liquid from (H1) to (H2) will be

If the value of coefficient of discharge increases, the discharge through the orifice decreases.

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

If a pitot tube is placed with its nose upstream, downstream or sideways, the reading will be the same in every case.

The coefficient of discharge is the ratio of theoretical discharge to the actual discharge through an orifice.

In two dimensional flow, the flow does not take place in a curve.

All the gases are considered to have compressible flow and all the liquids are considered to have incompressible flow.

A flow through an expanding tube at increasing rate is called unsteady non-uniform flow.