Fluid Mechanics Quizzes: Test Your Understanding

Question 1

In fluid mechanics, the principle of conservation of mass states that:

Accepted Answer

The mass of fluid flowing through a system remains constant over time.

Answer

The velocity of fluid flowing through a system remains constant over time.

Answer

The pressure of fluid flowing through a system remains constant over time.

Answer

The temperature of fluid flowing through a system remains constant over time.

Question 2

Viscosity measures a fluid's resistance to flow. Explain how viscosity impacts fluid flow and provide real-world examples to illustrate its practical significance.

Accepted Answer

Viscosity determines how easily a fluid flows, with higher viscosity fluids flowing more slowly than lower viscosity fluids.

Answer

Viscosity has no effect on fluid flow.

Answer

Viscosity only affects liquids, not gases.

Answer

Viscosity is only important in high-speed fluid flows.

Question 3

Which of the following is NOT a fundamental fluid property?

Accepted Answer

Elasticity

Answer

Density

Answer

Viscosity

Answer

Compressibility

Question 4

The pressure at a point in a fluid is defined as:

Accepted Answer

The force acting per unit area on a surface at that point perpendicular to the surface

Answer

The weight of the fluid above that point

Answer

The rate of change of pressure with depth

Answer

Zero if the fluid is not moving

Question 5

Which of the following equations represents the relationship between pressure, density, and depth in a fluid?

Accepted Answer

p = ρgh

Answer

p = ρgV

Answer

p = V/ρg

Answer

p = ρV/g

Question 6

The Reynolds number is a dimensionless quantity that characterizes:

Accepted Answer

The ratio of inertial forces to viscous forces in a fluid flow

Answer

The ratio of pressure forces to inertial forces in a fluid flow

Answer

The ratio of viscous forces to pressure forces in a fluid flow

Answer

The ratio of inertial forces to gravitational forces in a fluid flow

Question 7

The Bernoulli equation is used to:

Accepted Answer

Relate pressure, velocity, and height in an incompressible fluid flow

Answer

Calculate the force exerted by a fluid on a submerged object

Answer

Determine the efficiency of a pump

Answer

Predict the flow rate of a fluid through a pipe

Question 8

Which type of fluid flow is characterized by irregular and random motion?

Accepted Answer

Turbulent

Answer

Laminar

Answer

Viscous

Answer

Inviscid

Question 9

Which fluid property measures the resistance to flow?

Accepted Answer

Viscosity

Answer

Density

Answer

Specific gravity

Answer

Surface tension

Question 10

The ratio of inertial forces to viscous forces is characterized by:

Accepted Answer

The Reynolds number

Answer

The Froude number

Answer

The Mach number

Answer

The Prandtl number

Question 11

The law stating mass can neither be created nor destroyed is:

Accepted Answer

Conservation of mass

Answer

Conservation of energy

Answer

Conservation of momentum

Answer

Conservation of angular momentum

Question 12

In fluid mechanics, a fundamental dimension is not:

Accepted Answer

Temperature

Answer

Mass

Answer

Length

Answer

Time

Question 13

Which of the following is NOT a fundamental fluid property that characterizes the behavior of a fluid?

Accepted Answer

Force

Answer

Density

Answer

Viscosity

Answer

Temperature

Question 14

A fluid at rest is subjected to a pressure of 10 kPa at the surface. What is the absolute pressure at a depth of 2 m below the surface, considering atmospheric pressure is 101.3 kPa?

Accepted Answer

111.3 kPa

Answer

91.3 kPa

Answer

121.3 kPa

Answer

110.13 kPa

Question 15

Which of the following equations accurately represents Bernoulli's principle for an incompressible, inviscid fluid?

Accepted Answer

P1 + 1/2ρv1² + ρgh1 = P2 + 1/2ρv2² + ρgh2

Answer

P1 - 1/2ρv1² - ρgh1 = P2 - 1/2ρv2² - ρgh2

Answer

F = ma

Answer

E = mc²

Question 16

What is the primary distinction between laminar and turbulent flow regimes?

Accepted Answer

Laminar flow is characterized by smooth, orderly flow, while turbulent flow is characterized by irregular, chaotic flow.

Answer

Laminar flow occurs at higher velocities than turbulent flow.

Answer

Laminar flow is more efficient than turbulent flow.

Answer

Turbulent flow occurs in pipes with smaller diameters than laminar flow.

Question 17

Which of the following devices is commonly used to measure the pressure of a fluid accurately?

Accepted Answer

Manometer

Answer

Barometer

Answer

Anemometer

Answer

Thermometer

Question 18

What is the significance of the Reynolds number in characterizing fluid flow?

Accepted Answer

It is a dimensionless number that characterizes the ratio of inertia forces to viscous forces in a fluid flow.

Answer

It is a measure of the pressure drop in a pipe.

Answer

It is a measure of the velocity of a fluid.

Answer

It is a measure of the fluid's density.

Question 19

What is the fundamental difference between closed and open channel flows?

Accepted Answer

Closed channel flow occurs in a pipe or duct, while open channel flow occurs in a channel with a free surface.

Answer

Closed channel flow is always laminar, while open channel flow can be laminar or turbulent.

Answer

Closed channel flow is more common than open channel flow.

Answer

Open channel flow is more efficient than closed channel flow.

Question 20

Which of the following is NOT a recognized type of fluid friction?

Accepted Answer

Induced friction

Answer

Skin friction

Answer

Form friction

Answer

Wave friction

Question 21

Which of the following is a fundamental property of fluids?

Accepted Answer

Density

Answer

Hardness

Answer

Strength

Answer

Malleability

Question 22

In a fluid, pressure is considered a:

Accepted Answer

Scalar quantity

Answer

Vector quantity

Answer

Stress

Answer

Force

Question 23

Which equation represents the principle of continuity for incompressible flow?

Accepted Answer

ρAV = constant

Answer

ρgh = constant

Answer

F = ma

Answer

Q = V/t

Question 24

Which dimensionless number is commonly used to characterize fluid flow similarity?

Accepted Answer

Reynolds number

Answer

Froude number

Answer

Mach number

Answer

Grashof number

Question 25

The primary function of a pump is to increase:

Accepted Answer

Pressure

Answer

Volume

Answer

Temperature

Answer

Density

Question 26

An ideal fluid is characterized as:

Accepted Answer

Incompressible and inviscid

Answer

Compressible and inviscid

Answer

Incompressible and viscous

Answer

Compressible and viscous

Question 27

Which property is NOT fundamental to fluids?

Accepted Answer

Volume

Answer

Density

Answer

Viscosity

Answer

Temperature

Question 28

Fluid pressure at a particular point is:

Accepted Answer

Equal in all directions

Answer

Greatest in the vertical direction

Answer

Greatest in the horizontal direction

Answer

Zero

Question 29

The Bernoulli equation applies to:

Accepted Answer

Inviscid, incompressible fluids

Answer

Viscous, incompressible fluids

Answer

Inviscid, compressible fluids

Answer

Viscous, compressible fluids

Question 30

The continuity equation represents the principle of:

Accepted Answer

Mass conservation

Answer

Energy conservation

Answer

Momentum conservation

Answer

Angular momentum conservation

Question 31

The Navier-Stokes equations describe:

Accepted Answer

Motion of viscous fluids

Answer

Motion of inviscid fluids

Answer

Motion of compressible fluids

Answer

Motion of incompressible fluids

Question 32

For a fluid at rest, which equation correctly calculates the pressure at a depth 'h'?

Accepted Answer

P = ρgh

Answer

P = hρg

Answer

P = ghρ

Answer

P = ρg/h

Question 33

Which type of fluid flow is characterized by random and unpredictable motion of fluid particles?

Accepted Answer

Turbulent flow

Answer

Laminar flow

Answer

Compressible flow

Answer

Incompressible flow

Question 34

Which boundary condition for fluid flow states that the velocity of the fluid is zero at a solid surface?

Accepted Answer

No-slip condition

Answer

Inviscid flow condition

Answer

Irrotational flow condition

Answer

Zero-pressure gradient condition

Question 35

A fluid is at rest when it:

Accepted Answer

Is not moving

Answer

Is moving with constant velocity

Answer

Is moving with constant acceleration

Answer

Is flowing through a pipe

Question 36

The pressure at a point in a fluid is:

Accepted Answer

Equal in all directions

Answer

Greater in the vertical direction

Answer

Greater in the horizontal direction

Answer

Zero

Question 37

A centrifugal pump is primarily used to:

Accepted Answer

Increase the pressure of a fluid

Answer

Increase the velocity of a fluid

Answer

Decrease the pressure of a fluid

Answer

Decrease the velocity of a fluid

Question 38

MCQ-Improved-1: Which property is NOT a characteristic of fluids?

Accepted Answer

Mass

Answer

Density

Answer

Viscosity

Answer

Temperature

Question 39

MCQ-Improved-4: The Reynolds number is a dimensionless parameter that characterizes:

Accepted Answer

Fluid flow regime

Answer

Fluid viscosity

Answer

Fluid density

Answer

Fluid pressure

Question 40

MCQ-Improved-5: Which device is commonly used to measure fluid flow rate?

Accepted Answer

Venturi meter

Answer

Control valve

Answer

Separator

Answer

Pump

Question 41

MCQ-Improved-9: Fluid viscosity is related to:

Accepted Answer

Resistance to flow

Answer

Buoyancy

Answer

Elasticity

Answer

Surface tension

Question 42

MCQ-Improved-10: Incompressible fluids are characterized by:

Accepted Answer

Constant density

Answer

Variable viscosity

Answer

High compressibility

Answer

Non-Newtonian behavior

Question 43

A fluid is considered to be at rest when:

Accepted Answer

Both shear and normal stresses are zero

Answer

Shear stresses are zero

Answer

Normal stresses are zero

Answer

Pressure is zero

Question 44

In a fluid of constant density, the pressure at a depth 'h' below the free surface is given by:

Accepted Answer

ρgh

Answer

ρh/g

Answer

gh/ρ

Answer

ρ/gh

Question 45

The boundary layer developing on a flat plate typically undergoes a transition from:

Accepted Answer

Laminar flow near the leading edge to turbulent flow near the trailing edge

Answer

Turbulent flow near the leading edge to laminar flow near the trailing edge

Answer

Laminar flow throughout its length

Answer

Turbulent flow throughout its length

Question 46

In a fully developed laminar flow within a circular pipe, the velocity profile is:

Accepted Answer

Parabolic

Answer

Linear

Answer

Exponential

Answer

Triangular

Question 47

The Bernoulli equation primarily describes which principle?

Accepted Answer

Conservation of energy

Answer

Conservation of mass

Answer

Conservation of momentum

Answer

Conservation of angular momentum

Question 48

The Reynolds number is a dimensionless quantity primarily used for:

Accepted Answer

Characterizing flow regimes

Answer

Predicting pressure drop

Answer

Determining fluid viscosity

Answer

Calculating fluid velocity

Question 49

The concept of resistance encountered by fluids is quantified by:

Accepted Answer

Drag coefficient

Answer

Lift coefficient

Answer

Pressure coefficient

Answer

Reynolds number

Question 50

The ratio of inertial forces to viscous forces in fluid flow is represented by:

Accepted Answer

Reynolds number

Answer

Froude number

Answer

Mach number

Answer

Euler number

Question 51

Which of the following is NOT a property commonly associated with fluids?

Accepted Answer

Elasticity

Answer

Density

Answer

Viscosity

Answer

Surface tension

Question 52

Pressure, in the context of fluids, can be defined as:

Accepted Answer

Force acting perpendicular to a surface per unit area

Answer

Force acting parallel to a surface per unit volume

Answer

Weight acting perpendicular to a surface per unit area

Answer

Weight acting parallel to a surface per unit volume

Question 53

Which of the following is NOT a type of fluid flow regime?

Accepted Answer

Compressible

Answer

Laminar

Answer

Turbulent

Answer

Rotational

Question 54

The Bernoulli equation is primarily used to analyze:

Accepted Answer

Energy conservation in fluid flow systems

Answer

Momentum conservation in fluid flow systems

Answer

Pressure distribution in fluids

Answer

Flow rate calculations in pipes

Question 55

The dynamic viscosity of a fluid is a measure of its:

Accepted Answer

Resistance to flow

Answer

Mass per unit volume

Answer

Pressure

Answer

Temperature

Question 56

The Reynolds number is a dimensionless quantity used to characterize:

Accepted Answer

Flow regime based on the ratio of inertial to viscous forces

Answer

Fluid viscosity

Answer

Pipe diameter

Answer

Pressure drop

Question 57

Fluid statics deals with the study of:

Accepted Answer

Fluids at rest

Answer

Fluids in motion

Answer

Fluids under pressure

Answer

Fluids in pipes

Question 58

Describe the physical significance of the Reynolds number in fluid mechanics. Explain how it affects the flow regime and determines the transition between laminar and turbulent flow.

Accepted Answer

The Reynolds number is a dimensionless parameter that represents the ratio of inertial forces to viscous forces acting on a fluid. A low Reynolds number indicates laminar flow, while a high Reynolds number signifies turbulent flow.

Answer

The Reynolds number solely measures the fluid's density.

Answer

The Reynolds number solely measures the fluid's viscosity.

Answer

The Reynolds number solely measures the fluid's velocity.

Question 59

Which of the following is a fundamental thermophysical property of a fluid?

Accepted Answer

Density

Answer

Electrical conductivity

Answer

Hardness

Answer

Melting point

Question 60

Which of the following equations describes the relationship between pressure, density, and depth in a fluid?

Accepted Answer

p = ρgh

Answer

p = ρgV

Answer

p = V/ρg

Question 61

The Bernoulli equation describes:

Accepted Answer

The conservation of energy in an incompressible fluid

Answer

The conservation of momentum in a fluid

Answer

The conservation of mass in a fluid

Question 62

The Reynolds number is a dimensionless parameter that characterizes:

Accepted Answer

The ratio of inertial forces to viscous forces in a fluid

Answer

The ratio of surface tension forces to body forces in a fluid

Answer

The ratio of pressure forces to gravitational forces in a fluid

Question 63

Which of the following is a region in a fluid flow where viscosity is significant?

Accepted Answer

Boundary layer

Answer

Turbulent zone

Answer

Inviscid core

Answer

Stagnation point

Question 64

The drag force acting on a sphere in a fluid is:

Accepted Answer

Proportional to the square of the velocity

Answer

Proportional to the square root of the velocity

Answer

Proportional to the velocity

Answer

Independent of the velocity