Fluid Mechanics MCQ (Multiple Choice Questions)

Here are 1000 Fluid Mechanics MCQ (Chapterwise).

1. What is fluid mechanics?
a) Study of fluid behaviour at rest
b) Study of fluid behaviour in motion
c) Study of fluid behaviour at rest and in motion
d) Study of fluid behaviour at rest and in motion
View Answer

Answer: c
Explanation: The study of fluid behaviour (liquids, gases, blood, and plasmas) at rest and in motion is known as fluid mechanics. Fluid mechanics has numerous applications in mechanical and chemical engineering, as well as biological and astrophysical systems.

2. Which of the following is the basic principle of fluid mechanics?
a) Momentum principle
b) Energy equation
c) Continuity equation
d) All of the mentioned
View Answer

Answer: d
Explanation: The continuity equation (i.e. mass conservation), the momentum principle (or momentum conservation), and the energy equation are the three basic fluid mechanics principles.

3. What is fluid mechanics used for?
a) Fluid mechanics enables to comprehend the behaviour of solid fluids under pressure
b) Fluid mechanics enables to comprehend the behaviour of fluids under a variety of forces & atmospheric conditions
c) Fluid mechanics enables to comprehend the behaviour of fluids under various temperatures only
d) None of the mentioned
View Answer

Answer: b
Explanation: Fluid mechanics enables to comprehend the behaviour of fluids under a variety of forces and atmospheric conditions, as well as to select the appropriate fluid for a variety of applications.

4. If a person studies about a fluid which is at rest, what will you call his domain of study?
a) Fluid Dynamics
b) Fluid Mechanics
c) Fluid Statics
d) Fluid Kinematics
View Answer

Answer: c
Explanation: Fluid Mechanics deals with the study of fluid at rest or in motion with or without the consideration of forces, Fluid Statics is the study of fluid at rest, Fluid Kinematics is the study of fluid in motion without consideration of forces and Fluid Dynamics is the study of fluid in motion considering the application forces.

5. Which among the following is the standard symbol for Atwood number?
a) Ar
b) A
c) a
d) AR
View Answer

Answer: b
Explanation: The standard symbol for Atwood number is A. Atwood’s number in fluid mechanics deals with the onset of instabilities in mixtures of fluid. It is due to the density differences in fluid.
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6. Which of the following method is used exclusively in fluid mechanics?
a) Eulerian method
b) Lagrangian method
c) Neither Lagrangian nor Eulerian method
d) Both Lagrangian and Eulerian methods
View Answer

Answer: a
Explanation: In Fluid Mechanics, the matter of concern is the general state of motion at various points in the fluid system (as in Eulerian approach) rather than the motion of each particle (as in Lagrangian approach). Hence, the Eulerian method is extensively used in Fluid Mechanics.

7. Which of the following method is most commonly used in fluid mechanics for analysis?
a) Eulerian Method
b) Control volume analysis
c) Langragian method
d) None of the mentioned
View Answer

Answer: a
Explanation: In Eulerian method,we describe velocity, acceleration pressure etc at a point in flow field.hence, it is also most commonly used in fluid mechanics.

8. When is a fluid called turbulent?
a) High viscosity of fluid
b) Reynolds number is greater than 2000
c) Reynolds number is less than 2000
d) The density of the fluid is low
View Answer

Answer: b
Explanation: Reynolds number is a dimensionless quantity. It helps to predict the flow pattern in fluid mechanics. At high Reynolds number, the flow has a very high density, due to which the value of Reynolds number is greater than 2000.

9. Which among the following is the standard symbol for Blake number?
a) ba
b) b
c) Bi
d) Bl
View Answer

Answer: d
Explanation: The standard symbol for Blake number is B or Bl. Blake number in fluid mechanics deals with geology, fluid mechanics and porous media. It is due to the inertial over the viscous forces in fluid flow through porous media.

10. Stagnation point is the point in fluid mechanics where the velocity of the fluid at that point is _____
a) unity
b) constant
c) infinite
d) zero
View Answer

Answer: d
Explanation: Stagnation point is the point in fluid mechanics where the velocity of the fluid at that point is zero. Stagnation points occur at places where the fluid is brought to a state of rest by an object. They usually exist at the surface of objects.

11. Which among the following is the standard symbol for Archimedes number?
a) Ar
b) A
c) a
d) AR
View Answer

Answer: a
Explanation: The standard symbol for Archimedes number is Ar. Archimedes number in fluid mechanics deals with the motion of fluids. This takes place due to the differences in their densities. It was followed by the Archimedes principle.

12. Which among the following is referred to as the temperature at a stagnation point in the flow of fluids in fluid mechanics and thermodynamics.
a) Absolute temperature
b) Maximum temperature
c) Stagnation temperature
d) Hydraulic temperature
View Answer

Answer: c
Explanation: Stagnation temperature is the temperature at the stagnation point of the flow of fluids. In thermodynamics and fluid mechanics, these terms find application. At a stagnation point the speed of the fluid is zero and all of the kinetic energy has been converted to internal energy and is added to the local static enthalpy.

13. What is model testing?
a) Overall testing
b) Function testing
c) Partial testing
d) Performance testing
View Answer

Answer: d
Explanation: The process in fluid mechanics that is used to study the complex fluid dynamics is called as model testing. It is a performance testing. It helps to test models after a standard scaling. Models are usually smaller than the final design.

14. When is the fluid called laminar?
a) Low viscosity
b) The density of the fluid is high
c) Reynolds number is greater than 2000
d) Reynolds number is less than 2000
View Answer

Answer: d
Explanation: Reynolds number is a dimensionless quantity. It helps to predict the flow pattern in fluid mechanics. At low Reynolds number, the flow has a very low density, due to which the value of Reynolds number is less than 2000.
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15. Which among the following provides the third principle in fluid mechanics?
a) Conservation of Heat
b) Conservation of volume
c) Conservation of linear momentum
d) Conservation of mass
View Answer

Answer: c
Explanation: In fluid mechanics, the third principle is given by the conservation of linear momentum. It is in addition to the continuity of mass and conservation of energy. They are mostly seen in channel flow problems.

16. When a fluid is subjected to resistance, it undergoes a volumetric change due to __________
a) Cohesion
b) Strain
c) Compressibility
d) Adhesion
View Answer

Answer: c
Explanation: Compressibility is defined as a measure of relative change in volume of a fluid. In fluid mechanics, it is also called as isothermal compressibility due to increase in pressure and temperature.

17. The compressible flow is assumed to be _____________
a) Adiabatic only
b) Isentropic only
c) Isentropic and adiabatic
d) Polytropic
View Answer

Answer: b
Explanation: Compressible flow is a branch of fluid mechanics that deals with different types of flow. Its main significance lies in the change in fluid density. It deals with gas dynamics. Flow is assumed to be isentropic.

18. Principle of fluid mechanics works on the utilization of________
a) Velocity
b) Accelerating mass
c) Volume
d) Work
View Answer

Answer: d
Explanation: The Principle of fluid mechanics works on the utilization of useful work. The working is based on the force exerted by a fluid jet striking the surface and moving over a series of vanes about its axis.

19. Open channel flow takes place _______
a) In a pump
b) Within a cylindrical depth
c) On a free surface
d) In the pipe
View Answer

Answer: c
Explanation: Open channel flow is a flow that deals with hydraulics in fluid mechanics. It is a type of liquid flow that flows through a free surface. This free surface is called as a channel. And since the channel is free, it is called as an open channel flow.
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20. Which of the following is a type of fluid based on viscosity?
a) Real Fluid
b) Ideal Fluid
c) Newtonian Fluid
d) All of the mentioned
View Answer

Answer: d
Explanation: Fluid based on viscosity:
i) Real Fluid
ii) Ideal Fluid
iii) Newtonian Fluid
iv) Non-Newtonian Fluid
v) Ideal Plastic Fluid

21. The viscous force the relative motion between the adjacent layers of a fluid in motion. Which of the following flowing fits best in the sentence?
a) never affects
b) may effect under certain conditions
c) facilitates
d) opposes
View Answer

Answer: d
Explanation: Viscosity is the internal friction of a fluid in motion. It is the property by the virtue of which the relative motion between two adjacent fluid layers is opposed.

22. Pressure intensity or force due to pressure gradient for fluid at rest is considered as which of the following kind of force?
a) Body force
b) Force due to motion
c) Surface force
d) None of the mentioned
View Answer

Answer: c
Explanation: Pressure force is surface force.

23. Pressure variation for compressible fluid is maximum for which of the following kind of process?
a) Adiabatic
b) Quasi Static
c) Isothermal
d) None of the mentioned
View Answer

Answer: c
Explanation: Due to constant temperature, pressure variation for compressible fluid is maximum for isothermal process.

24. Which of the following principle is used for calculating the centre of pressure?
a) Principle of balancing of momentum
b) Principle of momentum
c) Principle of conservation of energy
d) None of the mentioned
View Answer

Answer: a
Explanation: We balance the moment in order to calculate the position of centre of pressure.

25. Which of the following cannot be the value of absolute pressure of a fluid at any point?
a) 0
b) 1.45 bar
c) – 1 bar
d) 24 bar
View Answer

Answer: c
Explanation: Absolute zero pressure is the reference used for the measurement of absolute pressure. Absolute zero pressure is possible (theoretically). Hence, 0 and positive values are possible, but a negative value is impossible.

26. When the body is completely or partially immersed in a fluid, how much its weight be distributed for it to be in stable equilibrium.
a) Is independent of weight distribution
b) Around the lower part
c) Around the upper part
d) None of the mentioned
View Answer

Answer: b
Explanation: When the weight distribution is around the lower part, the centre of gravity is at lower portion and hence below the centre of buoyancy which is condition for stable equilibrium.

27. Which of the following equation must be perfunctorily satisfied while dealing with fluid flow problems?
a) Newton’s third law
b) Law of conservation of momentum
c) Continuity equation
d) Newton’s second law
View Answer

Answer: c
Explanation: Continuity equation must be perfunctorily satisfied while dealing with fluid flow problems.

29. Which among the following is an assumption of Hagen-Poiseuille equation?
a) Fluid is uniform
b) Fluid is laminar
c) Fluid is turbulent
d) Fluid is compressible
View Answer

Answer: b
Explanation: Fluid flow is laminar as it is assumed to be incompressible and Newtonian. The flow is laminar through the pipe of constant cross section. Thus, there is no acceleration of fluid in the pipe. Therefore, Hagen-Poiseuille assumed that fluid flow is laminar.

30. Which of the following is a formula for the friction factor of circular pipes?
a) Re/64
b) 16/Re
c) 64/Re
d) Re/16
View Answer

Answer: c
Explanation: Circular pipes have a diameter treated in a round manner. For a fluid flow which is laminar head loss is directly proportional to the fluid velocity. Thus, friction factor is inversely proportional to its velocity. Therefore, the correct option is ‘64/Re’.

31. Which among the following is not global parameters of fluid?
a) Mass flow rate
b) Density
c) Viscosity
d) External diameter
View Answer

Answer: d
Explanation: External diameter is not a global parameter. It is one of the most essential pipelining parameters. It helps in determining the type of pipe and material to be used for the same.

32. Which of the following is the mathematical technique used to predict physical parameters?
a) Dimensional analysis
b) Temperature analysis
c) Pressure analysis
d) Combustion analysis
View Answer

Answer: a
Explanation: Dimensional analysis is a process which is used to determine physical parameters that influence the fluid flow. The analysis is based on the fundamental units. The fundamental units are mass, length and time.

33. Which among the following have the same forces acting on them?
a) Dynamic similarity
b) Geometric similarity
c) Conditional similarity
d) Kinematic similarity
View Answer

Answer: a
Explanation: Dynamic similarities have the same forces acting on them. That means, the ratios of all the forces acting on the fluid particles are constant. Also, the ratio of the forces acting on the boundary surfaces are also a constant.


Chapterwise Multiple Choice Questions on Fluid Mechanics

Fluid Mechanics MCQ - Multiple Choice Questions and Answers

Our 1000+ MCQs focus on all topics of the Fluid Mechanics subject, covering 100+ topics. This will help you to prepare for exams, contests, online tests, quizzes, viva-voce, interviews, and certifications. You can practice these MCQs chapter by chapter starting from the 1st chapter or you can jump to any chapter of your choice.
  1. Properties of Fluids
  2. Pressure and Its Measurement
  3. Hydrostatic Forces on Surfaces
  4. Buoyancy and Floatation
  5. Kinematics of Flow and Ideal Flow
  6. Fluid Dynamics
  7. Orifices, Mouthpieces, Notches and Weirs
  8. Viscous Flow & Turbulent Flow
  9. Flow Through Pipes
  10. Indicator Diagrams
  11. Dimensional and Model Analysis
  12. Boundary Layer Flow & Forces on Sub-merged Bodies
  13. Compressible Flow
  14. Flow in Open Channels
  15. Non Uniform Flow in Channels
  16. Impact of Jets and Jet Propulsion

1. Fluid Mechanics MCQ on Properties of Fluids

The section contains multiple choice questions and answers on fluid mechanics basics and properties, viscosity, vapor pressure, compressibility and bulk modulus, fluids types, surface tension, capillarity and thermodynamic properties.

  • Introduction to Fluid Mechanics
  • Fluid Properties – 1
  • Fluid Properties – 2
  • Viscosity – 1
  • Viscosity – 2
  • Vapor Pressure
  • Compressibility and Bulk Modulus
  • Types of Fluids
  • Surface Tension
  • Thermodynamic Properties & Compressibility
  • Surface Tension, Capillarity, Vapour Pressure and Cavitation
  • 2. Fluid Mechanics Multiple Choice Questions on Pressure and Its Measurement

    The section contains Fluid Mechanics questions and answers on pressure distribution in fluid, pressure measurement, pascals law and compression fluid pressure point.

  • Fluid Pressure
  • Pressure Distribution in a Fluid – 1
  • Pressure Distribution in a Fluid – 2
  • Fluid Pressure at a Point & Pascal’s Law
  • Measurement of Pressure, Simple & Differential Manometers
  • Pressure at a Point in Compressible Fluid
  • 3. Fluid Mechanics MCQ on Hydrostatic Forces on Surfaces

    The section contains Fluid Mechanics MCQs on hydrostatic force on plane area, pressure distribution in liquid, horizantal and inclined plane in liquid, total pressure and vertical plane surface.

  • Hydrostatic Force on Plane Area – 1
  • Hydrostatic Force on Plane Area – 2
  • Total Pressure & Vertical Plane Surface Submerged in a Liquid
  • Horizontal & Inclined Plane Surface Submerged in a Liquid
  • Pressure Distribution in a Liquid
  • 4. Fluid Mechanics Multiple Choice Questions on Buoyancy and Floatation

    The section contains Fluid Mechanics multiple choice questions and answers on buoyancy, metacenter and metacentric height, manometer and equilibrium conditions of submerged bodies.

  • Manometer
  • Buoyancy
  • Metacentre and Metacentric Height
  • Conditions of Equilibrium of a Floating and Submerged Bodies
  • 5. Fluid Mechanics MCQ on Kinematics of Flow and Ideal Flow

    The section contains Fluid Mechanics questions and answers on fluid flow types and methods, continuity equation & its dimensions, flow lines types, velocity and acceleration, vortex flow, important cases of potential and super imposed flow.

  • Types of Fluid Flow
  • Types of Flow Lines
  • Continuity Equation
  • Fluid Flow Methods and Types
  • Continuity Equation in Two and Three Dimensions
  • Velocity and Acceleration
  • Types of Motion & Vortex Flow
  • Important Cases of Potential Flow
  • Important Cases of Super Imposed Flow
  • 6. Multiple Choice Questions on Fluid Dynamics

    The section contains Fluid Mechanics MCQs on euler and bernoulli equations of motion, bernoulli applications, newtons first and second law, navier strokes equation, impulse and moment of momentum equation.

  • Introduction to Fluid Dynamics
  • Newton’s Second Law
  • First Law of Thermodynamics
  • Navier-Stokes Equations of Motion
  • Impulse Momentum Equation
  • Introduction, Euler’s & Bernoulli’s Equation of Motion
  • Bernoulli’s Equation for Real Fluids & Applications of Bernoulli’s Equation
  • 7. Fluid Mechanics MCQ on Orifices, Mouthpieces, Notches and Weirs

    The section contains Fluid Mechanics multiple choice questions and answers on orifice, notches and weirs classification, large orifice flows, discharge over notches or weirs, time required to empty reservoir with notches and weirs.

  • Classification of Orifice & Hydraulic Coefficients
  • Flow through Large Orifice
  • Classification of Notches and Weirs
  • Discharge over a Rectangular,Trapezoidal & Stepped Notch
  • Time Required to Empty a Reservoir with Weirs or Notches
  • Discharge Over different type of weirs
  • 8. Fluid Mechanics Multiple Choice Questions on Viscous Flow & Turbulent Flow

    The section contains Fluid Mechanics questions and answers on shear stress in viscous and turbulent flow, piston movement, flow of viscous fluid through circular pipes, power absorption, universal velocity distribution and viscosity coefficient methods.

  • Shear Stress and Pressure Gradient
  • Flow of Viscous Fluid Through Circular Pipes
  • Kinetic Energy Correction and Momentum Correction Factors
  • Power Absorbed in Viscous Flow
  • Loss of Head due to Friction in Viscous Flow
  • Movement of Piston in Dash Pot
  • Universal Velocity Distribution
  • Methods of Determination of Coefficient of Viscosity
  • 9. Fluid Mechanics MCQ on Flow Through Pipes

    The section contains Fluid Mechanics MCQs on energy losses in pipes, hydraulic gradient, series and parallel pipes, nozzles flow, pipes water hammer and pipe network.

  • Loss of Energy in Pipes
  • Hydraulic Gradient and Total Energy Line
  • Pipes in Series
  • Flow through Nozzles
  • Water Hammer in Pipes
  • Pipe Network
  • 10. Fluid Mechanics Multiple Choice Questions on Indicator Diagrams

    The section contains Fluid Mechanics multiple choice questions and answers on ideal indicator diagram, reciprocating pump maximum speed, acceleration effect in suction and delivery pipes on indicator diagrams.

  • Ideal Indicator Diagram
  • Effect of Acceleration in Suction and Delivery Pipes on Indicator Diagrams
  • Maximum Speed of a Reciprocating Pump
  • 11. Fluid Mechanics MCQ on Dimensional and Model Analysis

    The section contains Fluid Mechanics questions and answers on dimensional homogenity, model analysis, dimensionless numbers, similarities types and laws, testing on submerged bodies, moving fluid types and model classifications.

  • Dimensional Homogenity
  • Rayleighs Method
  • Model Analysis
  • Similitude-Types of Similarities
  • Types of Forces Acting in Moving Fluid
  • Model Testing of Partially Submerged Bodies
  • Dimensionless Numbers
  • 12. Fluid Mechanics Multiple Choice Questions on Boundary Layer Flow & Forces on Sub-merged Bodies

    The section contains Fluid Mechanics MCQs on sphere drag, turbulent boundary layer on flat plate and boundary layer separation.

  • Turbulent Boundary Layer on a Flat Plate
  • Separation of Boundary Layer
  • Drag on a Sphere
  • 13. Fluid Mechanics MCQ on Compressible Flow

    The section contains Fluid Mechanics multiple choice questions and answers on thermodynamic relations, compressible flow equations, sound or pressure wave velocity in fluid, stagnation properties, compressible fluid through orifices and nozzles.

  • Thermodynamic Relations
  • Basic Equations of Compressible Flow
  • Velocity of Sound or Pressure Wave in a Fluid – 1
  • Velocity of Sound or Pressure Wave in a Fluid – 2
  • Stagnation Properties
  • Area Velocity Relationship for Compressible Flow
  • Flow of Compressible Fluid through Orifices and Nozzles
  • 14. Fluid Mechanics Multiple Choice Questions on Flow in Open Channels

    The section contains Fluid Mechanics questions and answers on channel flow types, chezys formula, geometrical properties of rectangular section, triangular and trapezoidal section, manning’s equation, most economic rectangular section, trapezoidal and circular section, specific energy and different channel sections.

  • Types of Flow in Channels
  • Geometrical Properties of Rectangular Section
  • Geometrical Properties of Triangular Section – 1
  • Geometrical Properties of Triangular Section – 2
  • Geometrical Properties of Trapezoidal Section
  • Chezy’s Equation
  • Manning’s Equation – 1
  • Manning’s Equation – 2
  • Most Economic Rectangular Section
  • Most Economic Trapezoidal Section
  • Most Economic Circular Section – 1
  • Most Economic Circular Section – 2
  • Most Economic Circular Section – 3
  • Specific Energy – 1
  • Specific Energy – 2
  • Critical Flow in Different Channel Sections – 1
  • Critical Flow in Different Channel Sections – 2
  • 15. Fluid Mechanics MCQ on Non Uniform Flow in Channels

    The section contains Fluid Mechanics MCQs on gradually varied flow, gradually varied flow in wide rectangular channels, surface profiles characteristics, relation b/w water surface and channel bottom slopes, hydraulic jump, hydraulic jump types and location.

  • Gradually Varied Flow(GVF) – 1
  • Gradually Varied Flow(GVF) – 2
  • Gradually Varied Flow(GVF) – 3
  • Gradually Varied Flow(GVF) – 4
  • Gradually Varied Flow(GVF) – 5
  • Gradually Varied Flow in Wide Rectangular Channels
  • Relation between Water Surface Slopes and Channel Bottom Slopes
  • Characteristics of Surface Profiles
  • Hydraulic Jump
  • Types of Hydraulic Jumps
  • Location of a Hydraulic Jump
  • Specific Force
  • 16. Fluid Mechanics Multiple Choice Questions on Impact of Jets and Jet Propulsion

    The section contains Fluid Mechanics multiple choice questions and answers on exerted force by a jet on a vanes series, exerted force by a fluid jet in stationary flat inclined and curved plate.

  • Force Exerted by a Jet on a Stationary Flat Inclined Plate
  • Force Exerted by a Jet on a Stationary Curved Plate
  • Force Exerted by a Jet on a Series of Vanes
  • If you would like to learn "Fluid Mechanics" thoroughly, you should attempt to work on the complete set of 1000+ MCQs - multiple choice questions and answers mentioned above. It will immensely help anyone trying to crack an exam or an interview.

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