Fluid Mechanics Quiz Set-1 [2025]

Fluid Mechanics Quiz Set-1 [2025]

In this blog, we’ve curated 50+ thought-provoking multiple-choice questions covering the fundamental and advanced concepts of fluid mechanics. The “Fluid Mechanics Quiz Set-1 [2025]” is designed to help you revisit core principles, challenge your knowledge, and gain practical insights into fluid behavior and applications.

Whether you’re a mechanical or civil engineering student, a fluid dynamics enthusiast, or preparing for competitive exams, this quiz is the perfect tool to enhance your understanding of fluid mechanics.

Let’s dive into the “Fluid Mechanics Quiz Set-1 [2025]” and start exploring!

Fluid Mechanics

1 / 60

The branch of science which deals with study of properties of water is called as

Dynamics

Kinetics

Hydraulics

Pneumatics

2 / 60

The viscosity of a gas

decreases with increase in temperature

increases with increase in temperature

is independent of temperature

is independent of pressure for very high pressure intensities

3 / 60

Newton's law of viscosity relates

intensity of pressure and rate of angular deformation

shear stress and rate of angular deformation

shear stress, viscosity and temperature

viscosity and rate of angular deformation

4 / 60

Centre of buoyancy always

coincides with the centre of gravity

coincides with the centroid of the volume of fluid displaced

remains above the centre of gravity

remains below the centre of gravity

5 / 60

Metacentric height for small values of angle of heel is the distance between the

centre of gravity and centre of buoyancy

centre of gravity and metacentre

centre of buoyancy and metacentre

free surface and centre of buoyancy

6 / 60

A floating body is said to be in a state of stable equilibrium

when its metacentric height is zero

when the metacentre is above the centre of gravity

when the metacentre is below the centre of gravity

only when its centre of gravity is below its centre of buoyancy

7 / 60

The increase in metacentric height
i) increases stability
ii) decreases stability
iii) increases comfort for passengers
iv) decreases comfort for passengers
The correct answer is

(i) and (iii)

(i) and (iv)

(ii) and (iii)

(ii) and (iv)

8 / 60

The point in the immersed body through which the resultant pressure of the liquid may be taken to act is known as

center of gravity

center of buoyancy

center of pressure

metacentre

9 / 60

If a vessel containing liquid moves downward with a constant acceleration equal to 'g' then

the pressure throughout the liquid mass is atmospheric

there will be vacuum in the liquid

the pressure in the liquid mass is greater than hydrostatic pressure

none of the above

10 / 60

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

11 / 60

A right circular cylinder open at the top is filled with liquid and rotated about its vertical axis at such a speed that half the liquid spills out, then the pressure intensity at the center of bottom is

zero

one-fourth its value when cylinder was full

one-half its value when cylinder was full

cannot be predicted from the given data

12 / 60

The horizontal component of force on a curved surface is equal to the

product of pressure intensity at its centroid and area

force on a vertical projection of the curved surface

weight of liquid vertically above the curved surface

force on the horizontal projection of the curved surface

13 / 60

A closed tank containing water is moving in a horizontal direction along a straight line at a constant speed. The tank also contains a steel ball and a bubble of air. If the tank is decelerated horizontally, then
i) the ball will move to the front
ii) the bubble will move to the front
iii) the ball will move to the rear
iv) the bubble will move to the rear Find out which of the above statements is correct?

(i) and (ii)

(i) and (iv)

(ii) and (iii)

(iii) and (iv)

14 / 60

The eddy viscosity for turbulent flow is

a function of temperature only

a physical property of the fluid

dependent on the flow

independent of the flow

15 / 60

A 20 mm Dam pipe forks one branch being 10 mm diameter and the other 15 mm in diameter. The velocity in 10 mm pipe is 0.3 m/s and in the 15 mm pipe is 0.6 m/s calculate the rate of flow (Q) in cm3/s and velocity (V) in m/s in 20mm diameter pipe.

Q = 129.6 cm3/s, V= 0.413 m/s

Q = 192.6 cm3/s, V= 0.314 m/s

Q = 169.2 cm3/s, V= 0.134 m/s

Q = 291.6 cm3/s, V= 0.413 m/s

16 / 60

Flow at constant rate through a tapering pipe is
i) steady flow
ii) uniform flow
iii) unsteady flow

iv) non-uniform flow
The correct answer is

(i) and (ii)

(i) and (iv)

(ii) and (iii)

(ii) and (iv)

17 / 60

In a two dimensional incompressible steady flow around an airfoil, the stream lines are 2 cm apart at a great distance from the airfoil, where the velocity is 30m/sec. The velocity near the airfoil, where the stream lines are 1.5 cm apart, is

22.5 m/sec

33 m/sec

40 m/sec

90 m/sec

18 / 60

When the velocity distribution is uniform over the cross-section, the correction factor for momentum is

3/4

19 / 60

Least possible value of correction factor for
i) kinetic energy is zero
ii) kinetic energy is 1
iii) momentum is zero
iv) momentum is 1
The correct statements are

(i) and (iii)

(ii) and (iii)

(i) and (iv)

(ii) and (iv)

20 / 60

If the velocity is zero over half of the cross-sectional area and is uniform over the remaining half, then the momentum correction factor is

4/3

21 / 60

If velocity is zero over l/3rd of a cross-section and is uniform over remaining 2/3rd of the cross-section, then the correction factor for kinetic energy is

4/3

3/2

9/4

27/8

22 / 60

The motion of air mass in a tornado is a

free vortex motion

forced vortex motion

free vortex at center and forced vortex outside

forced vortex at center and free vortex outside

23 / 60

In a forced vortex motion, the velocity of flow is

directly proportional to its radial distance from axis of rotation

inversely proportional to its radial distance from the axis of rotation

inversely proportional to the square of its radial distance from the axis of rotation

directly proportional to the square of its radial distance from the axis of rotation

24 / 60

Stream lines and path lines always coincide in case of

steady flow

laminar flow

uniform flow

turbulent flow

25 / 60

Equation of continuity is based on the principle of conservation of

mass

energy

momentum

none of the above

26 / 60

In steady flow of a fluid, the total acceleration of any fluid particle

can be zero

is never zero

is always zero

is independent of coordinates

27 / 60

The pitot tube is used to measure

velocity at stagnation point

stagnation pressure

static pressure

dynamic pressure

28 / 60

Hot wire anemometer is used to measure

discharge

velocity of gas

pressure intensity of gas

pressure intensity of liquid

29 / 60

The theoretical value of coefficient of contraction of a sharp edged orifice is

0.611

0.85

0.98

1.00

30 / 60

Which of the following is used to measure the discharge?

current meter

venturimeter

pitot tube

hotwire anemometer

31 / 60

Select the incorrect statement

The pressure intensity at vena contracta is atmospheric

Contraction is least at vena contracta

Stream lines are parallel throughout the jet at vena contracta

Coefficient of contraction is always less than one

32 / 60

Size of a venturimeter is specified by

pipe diameter

throat diameter

angle of diverging section

both pipe diameter as well as throat diameter

33 / 60

Due to each end contraction, the discharge of rectangular sharp crested weir is reduced by

5 %

10 %

15 %

20 %

34 / 60

Which of the following is an incorrect statement?

Coefficient of contraction of a venturimeter is unity

Flow nozzle is cheaper than venturimeter but has higher energy loss

Discharge is independent of orientation of venturimeter whether it is horizontal, vertical or inclined

None of the above statement is correct

35 / 60

Coefficient of velocity of venturimeter

is independent of Reynolds number

decreases with higher Reynolds number

is equal to the coefficient of discharge of venturimeter

none of the above

36 / 60

The pressure at the summit of a syphon is

equal to atmospheric

less than atmospheric

more than atmospheric

none of the above

37 / 60

A.V between two stream lines represents

velocity

discharge

head

pressure

38 / 60

Coefficient of velocity for Borda's mouth piece running full is

0.611

0.707

0.855

1.00

39 / 60

Coefficient of discharge for a totally submerged orifice as compared to that for an orifice discharging free is

slightly less

slightly more

nearly half

equal

40 / 60

The major loss of energy in long pipes is due to

sudden enlargement

sudden contraction

gradual contraction or enlargement

friction

41 / 60

Coefficient of contraction for an external cylindrical mouthpiece is

1.00

0.855

0.70

0.611

42 / 60

Which of the following has highest coefficient of discharge?

sharp edged orifice

venturimeter

Borda's mouthpiece running full

Cipoletti weir

43 / 60

Which of the following statements is correct?

Lower critical Reynolds number is of no practical significance in pipe flow problems.

Upper critical Reynolds number is significant in pipe flow problems.

Lower critical Reynolds number has the value 2000 in pipe flow

Upper critical Reynolds number is the number at which turbulent flow changes to laminar flow

44 / 60

For a sphere of radius 15 cm moving with a uniform velocity of 2 m/sec through a liquid of specific gravity 0.9 and dynamic viscosity 0.8 poise, the Reynolds number will be

300

337.5

600

675

45 / 60

The shear stress distribution for a fluid flowing in between the parallel plates, both at rest, is

constant over the cross section

parabolic distribution across the section

zero at the mid plane and varies linearly with distance from mid plane

zero at plates and increases linearly to midpoint

46 / 60

Stanton diagram is a

log-log plot of friction factor against Reynolds number

log-log plot of relative roughness against Reynolds number

semi-log plot of friction factor against Reynolds number

semi-log plot of friction factor against relative roughness

47 / 60

The depth 'd' below the free surface at which the point velocity is equal to the average velocity of flow for a uniform laminar flow with a free surface, will be

where D is the depth of flow

0.423 D

0.577 D

0.223 D

0.707 D

48 / 60

The distance y from pipe boundary, at which the point velocity is equal to average velocity for turbulent flow, is

where R is radius of pipe.

0.223 R

0.423 R

0.577 R

0.707 R

49 / 60

If a sphere of diameter 1 cm falls in castor oil of kinematic viscosity 10 stokes, with a terminal velocity of 1.5 cm/sec, the coefficient of drag on the sphere is

less than 1

between 1 and 100

160

200

50 / 60

When an ideal fluid flows past a sphere,

highest intensity of pressure occurs around the circumference at right angles to flow

lowest pressure intensity occurs at front stagnation point

lowest pressure intensity occurs at rear stagnation point

total drag is zero

51 / 60

In case of an airfoil, the separation of flow occurs

at the extreme rear of body

at the extreme front of body

midway between rear and front of body

anywhere between rear and front of body depending upon Reynolds number

52 / 60

With the same cross-sectional area and immersed in same turbulent flow, the largest total drag will be on

a circular disc of plate held normal to flow

a sphere

a cylinder

a streamlined body

53 / 60

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

54 / 60

For hydro-dynamically smooth boundary, the friction coefficient for turbulent flow is

constant

dependent only on Reynolds number

a function of Reynolds number and relative roughness

dependent on relative roughness only

55 / 60

The value of friction factor 'f' for smooth pipes for Reynolds number 106 is approximately equal to

0.1

0.01

0.001

0.0001

56 / 60

For laminar flow in a pipe of circular cross-section, the Darcy's friction factor f is

directly proportional to Reynolds number and independent of pipe wall roughness

directly proportional to pipe wall roughness and independent of Reynolds number

inversely proportional to Reynolds number and independent of pipe wall roughness

inversely proportional to Reynolds number and directly proportional to pipe wall roughness

57 / 60

Separation of flow occurs when

the pressure intensity reaches a minimum

the cross-section of a channel is reduced

the boundary layer comes to rest

all of the above

58 / 60

The ratio of average velocity to maximum velocity for steady laminar flow in circular pipes is

2/3

3/2

59 / 60

The distance from pipe boundary, at which the turbulent shear stress is one third die wall shear stress, is

Where R is the radius of pipe

1/3 R

1/2 R

2/3 R

3/4R

60 / 60

The velocity distribution for laminar flow through a circular tube

is constant over the cross-section

varies linearly from zero at walls to maximum at centre

varies parabolically with maximum at the centre

none of the above

Your score is

The average score is 0%

Understanding Fluid Mechanics: A Comprehensive Guide

Fluid mechanics, a critical branch of engineering and physics, plays a pivotal role in understanding the behavior of fluids—both liquids and gases—in motion and at rest. This fascinating discipline has vast applications ranging from designing water distribution systems to predicting weather patterns, making it indispensable for engineers, scientists, and researchers alike.

Table of Contents

What is Fluid Mechanics?

At its core, fluid mechanics studies how fluids behave under various forces and in different environments. It is divided into two main subfields:

Fluid Statics: The study of fluids at rest, focusing on pressure distribution and buoyancy.
Fluid Dynamics: The study of fluids in motion, examining factors like velocity, flow rates, and energy conservation.

See Also: Engineering Mechanics Quiz Set-1

Fundamental Principles of Fluid Mechanics

To understand fluid mechanics, one must grasp several key principles:

Continuity Equation: This principle ensures mass conservation within a flow system.
Bernoulli’s Equation: A cornerstone of fluid dynamics, it describes the relationship between pressure, velocity, and elevation in steady flow.
Navier-Stokes Equations: These equations govern the motion of viscous fluids, incorporating factors like velocity, pressure, and external forces.
Pascal’s Law: States that pressure applied to an enclosed fluid is transmitted undiminished in all directions.

See Also: Steel Structures Quiz Set-1

Applications of Fluid Mechanics

Fluid mechanics finds applications in a multitude of fields, including:

Civil Engineering: Designing dams, canals, and water treatment plants.
Mechanical Engineering: Optimizing the performance of turbines, pumps, and HVAC systems.
Aerospace Engineering: Analyzing airflow around aircraft to improve efficiency and safety.
Environmental Science: Modeling pollution dispersion and managing natural water resources.
Biomedical Engineering: Understanding blood flow in the human body to improve medical devices.

See Also: Concrete Structures Quiz Set-1

Challenges in Fluid Mechanics

Despite its vast applications, fluid mechanics poses several challenges:

Complexity of Equations: Solving Navier-Stokes equations for turbulent flows remains one of the greatest challenges in physics.
Real-World Conditions: Factors like temperature, pressure, and material properties often complicate theoretical models.
Interdisciplinary Nature: Combining principles from mathematics, physics, and engineering can be demanding for researchers.

See Also: Theory of Structures Quiz Set-1

Future Trends in Fluid Mechanics

With advancements in technology, the field of fluid mechanics continues to evolve. Some emerging trends include:

Computational Fluid Dynamics (CFD): Using computer simulations to model fluid behavior with unprecedented accuracy.
Sustainable Solutions: Developing energy-efficient systems, such as wind turbines and solar-powered desalination plants.
Bio-inspired Designs: Mimicking natural fluid systems, like fish swimming or bird flight, to create innovative engineering solutions.

Conclusion

Fluid mechanics is an essential discipline that underpins many aspects of modern life. From powering industries to solving environmental challenges, its applications are as vast as its potential. Whether you’re a student, an engineer, or simply curious about the wonders of fluid behavior, delving into fluid mechanics offers insights into the forces that shape our world.

Frequently Asked Questions (FAQ)

1. What are the primary differences between fluid statics and fluid dynamics?

Fluid statics deals with fluids at rest, focusing on pressure and buoyancy, while fluid dynamics examines fluids in motion, including flow rates and energy changes.

2. How is Computational Fluid Dynamics (CFD) changing the field of fluid mechanics?

CFD uses advanced computer simulations to analyze and predict fluid behavior, making it easier to solve complex problems and design efficient systems.

3. What industries benefit the most from fluid mechanics applications?

Industries like civil engineering, aerospace, mechanical systems, environmental science, and biomedical engineering heavily rely on fluid mechanics for innovation and efficiency.

Let us know your thoughts or questions about fluid mechanics in the comments below. We’d love to hear from you!

What is Fluid Mechanics?

Fundamental Principles of Fluid Mechanics

Applications of Fluid Mechanics

Challenges in Fluid Mechanics

Future Trends in Fluid Mechanics

Conclusion

Frequently Asked Questions (FAQ)

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