Fluid Kinematics: Master Fluid Motion in Mechanical Engineering

Question 1

What is a streamline, and why is it important in fluid flow analysis?

Accepted Answer

A line that touches the velocity vector at a specific point in the fluid flow field.

Answer

A path that follows a specific fluid particle over time.

Answer

A line that connects two points in the fluid with equal pressure.

Answer

A surface where the fluid's velocity is zero.

Question 2

In steady, incompressible, one-dimensional flow through a pipe with varying cross-sectional area, what is a direct consequence of the continuity equation?

Accepted Answer

Velocity is inversely proportional to the cross-sectional area.

Answer

Acceleration is zero everywhere in the flow.

Answer

The pressure gradient is constant along the pipe.

Question 3

Identify the incorrect characteristic of a streamline.

Accepted Answer

Depicts the path of a single fluid particle over time

Answer

Tangential to the velocity vector at any point

Answer

Indicates the direction of fluid flow at a point

Answer

Visual representation of the flow field

Question 4

Differentiate between a pathline and a streakline.

Accepted Answer

A pathline tracks an individual fluid particle, while a streakline shows the path of all particles passing through a specific point.

Answer

A streakline tracks an individual fluid particle, while a pathline shows the path of all particles passing through a specific point.

Answer

Both terms refer to the same concept.

Answer

There is no distinction between a pathline and a streakline.

Question 5

Which condition is crucial for irrotational flow?

Accepted Answer

Curl-free velocity field

Answer

Divergence-free acceleration field

Answer

Steady flow

Answer

Incompressible fluid

Question 6

State the equation of continuity for an incompressible fluid.

Accepted Answer

ρAv = constant

Answer

ρu = constant

Answer

Av = constant

Answer

u = constant

Question 7

Which is NOT a type of fluid flow?

Accepted Answer

Ideal flow

Answer

Laminar flow

Answer

Turbulent flow

Answer

Compressible flow

Question 8

What is the primary purpose of the Reynolds number?

Accepted Answer

Characterizing the flow regime (laminar or turbulent)

Answer

Calculating pressure drop in a pipe

Answer

Determining velocity profile in a boundary layer

Answer

Finding the drag force on a body

Question 9

Identify the assumption NOT made in potential flow theory.

Accepted Answer

Negligible viscosity

Answer

Irrotational flow

Answer

Incompressible fluid

Answer

Steady flow

Question 10

In fluid kinematics, a streamline refers to:

Accepted Answer

The path traced by a fluid particle instantaneously

Answer

The line where fluid velocity is zero

Answer

The curve along which fluid pressure remains constant

Answer

The trajectory perpendicular to the velocity vector

Question 11

What does the velocity field represent in fluid mechanics?

Accepted Answer

The velocity and direction of fluid flow at every point

Answer

The rate of change of fluid displacement over time

Answer

The acceleration of fluid particles at a given instant

Answer

The pressure gradient influencing the fluid

Question 12

Regarding a fluid particle moving along a streamline, how are its velocity and acceleration related?

Accepted Answer

Velocity and acceleration can be either parallel or perpendicular

Answer

Velocity and acceleration are always perpendicular

Answer

Velocity and acceleration are always parallel

Answer

Velocity and acceleration have equal magnitudes but opposite directions

Question 13

Define a streakline in fluid kinematics:

Accepted Answer

The path traced by a group of fluid particles over time

Answer

The line connecting points of maximum fluid pressure

Answer

The curve with the highest fluid velocity

Answer

The line tangent to the velocity vector at any point

Question 14

Which of the below is NOT a valid type of fluid flow?

Accepted Answer

Subsonic flow

Answer

Laminar flow

Answer

Turbulent flow

Answer

Compressible flow

Question 15

What do pathlines represent in fluid kinematics?

Accepted Answer

The trajectory of an individual fluid particle over time

Answer

The velocity at various points in the flow

Answer

The pressure distribution within the flow

Answer

The acceleration of fluid particles

Question 16

Which of the following is the definition of a pathline?

Accepted Answer

The trajectory of an individual fluid particle as it flows

Answer

A line connecting points of equal velocity

Answer

A line tangent to the velocity vector at a given point

Answer

The path taken by a dye particle as it flows

Question 17

Which type of fluid flow exhibits smooth, orderly motion without turbulence?

Accepted Answer

Laminar flow

Answer

Turbulent flow

Answer

Viscous flow

Answer

Inviscid flow

Question 18

What is the primary significance of a streamline?

Accepted Answer

It indicates the direction of fluid flow at a given point

Answer

It depicts the path of a specific fluid particle

Answer

It represents the boundary between different fluids

Answer

It provides information about the velocity gradient

Question 19

Identify the scalar quantity among the following:

Accepted Answer

Pressure

Answer

Velocity

Answer

Acceleration

Answer

Shear stress

Question 20

The continuity equation primarily expresses the conservation of which physical property?

Accepted Answer

Mass

Answer

Energy

Answer

Momentum

Answer

Angular momentum

Question 21

Which property characterizes the resistance of a fluid to flow?

Accepted Answer

Viscosity

Answer

Density

Answer

Kinematic viscosity

Answer

Specific gravity

Question 22

The Reynolds number is a dimensionless parameter used to analyze what aspect of fluid flow?

Accepted Answer

Flow regime

Answer

Boundary layer thickness

Answer

Pressure drop

Answer

Heat transfer coefficient

Question 23

Which type of boundary layer is characterized by the presence of flow reversal?

Accepted Answer

Separated boundary layer

Answer

Laminar boundary layer

Answer

Turbulent boundary layer

Answer

Blasius boundary layer

Question 24

What is the primary purpose of the Navier-Stokes equations?

Accepted Answer

Predicting the velocity and pressure distribution within a fluid

Answer

Describing fluid flow in three dimensions

Answer

Calculating the forces acting on a fluid

Answer

Determining the stability of fluid flow

Question 25

Which of the following is an atypical application of fluid kinematics?

Accepted Answer

Monitoring and controlling traffic flow

Answer

Aerodynamic design of vehicles

Answer

Predicting weather patterns

Answer

Design of water distribution systems

Question 26

Which of the following is a type of fluid flow line that indicates the path of an individual fluid particle?

Accepted Answer

Pathline

Answer

Streamline

Answer

Isovel

Answer

Streakline

Question 27

The velocity field of a fluid is best described as:

Accepted Answer

A vector field that describes the velocity of the fluid at every point in space.

Answer

A scalar field that describes the speed of the fluid at every point in space.

Answer

A tensor field that describes the velocity gradient of the fluid at every point in space.

Answer

A vector field that describes the acceleration of the fluid at every point in space.

Question 28

What does the Reynolds number represent?

Accepted Answer

Ratio of inertial forces to viscous forces in a fluid flow.

Answer

Ratio of pressure forces to viscous forces in a fluid flow.

Answer

Ratio of gravitational forces to viscous forces in a fluid flow.

Answer

Ratio of surface tension forces to viscous forces in a fluid flow.

Question 29

Which type of fluid flow is characterized by a high Reynolds number and a significant pressure gradient?

Accepted Answer

Turbulent flow

Answer

Laminar flow

Answer

Viscous flow

Answer

Potential flow

Question 30

What is the primary characteristic of the boundary layer in a fluid flow?

Accepted Answer

Region of fluid near a solid surface with altered velocity due to its presence.

Answer

Region of fluid near a solid surface with altered pressure due to its presence.

Answer

Region of fluid near a solid surface with altered temperature due to its presence.

Answer

Region of fluid near a solid surface with altered density due to its presence.

Question 31

What is the path that a specific fluid particle follows called?

Accepted Answer

Pathline

Answer

Streakline

Answer

Streamline

Question 32

Which type of flow is characterized by constant velocity at a given point over time?

Accepted Answer

Steady flow

Answer

Unsteady flow

Answer

Laminar flow

Answer

Turbulent flow

Question 33

What term describes the abrupt change in fluid flow direction caused by an obstacle?

Accepted Answer

Separation

Answer

Turbulence

Answer

Cavitation

Answer

Stagnation

Question 34

Which equation expresses the conservation of mass for a fluid?

Accepted Answer

Continuity equation

Answer

Energy equation

Answer

Momentum equation

Answer

Navier-Stokes equation

Question 35

What is the primary distinction between laminar and turbulent boundary layers?

Accepted Answer

Laminar flow is orderly, while turbulent flow is chaotic and has eddies.

Answer

Laminar flow has a higher velocity gradient than turbulent flow.

Answer

Turbulent flow is more likely to cause drag.

Question 36

What is the significance of the Reynolds number in fluid mechanics?

Accepted Answer

It determines the transition between laminar and turbulent flow.

Answer

It is a measure of the fluid's viscosity.

Answer

It is used to calculate the drag force on an object.

Question 37

Which of the following most accurately describes a streamline?

Accepted Answer

A curve whose tangent at any point coincides with the velocity vector of the fluid at that point

Answer

A circle enclosing a region of constant pressure

Answer

A straight line connecting two fixed points in the fluid

Question 38

A pathline differs from a streakline primarily because it:

Accepted Answer

Tracks the trajectory of an individual fluid particle over time

Answer

Is always a straight line

Answer

Describes the velocity field of the fluid

Answer

Is independent of time

Question 39

In steady flow, the velocity:

Accepted Answer

Remains constant with respect to time at a given point in space

Answer

Changes with position but not with time

Answer

Changes with both time and position

Answer

Changes with time but not with position

Question 40

Which type of fluid flow exhibits no velocity gradient?

Accepted Answer

Uniform flow

Answer

Turbulent flow

Answer

Laminar flow

Answer

Irrotational flow

Question 41

The continuity equation expresses the principle of conservation of:

Accepted Answer

Mass

Answer

Volume

Answer

Momentum

Answer

Energy

Question 42

The acceleration of a fluid particle is defined as:

Accepted Answer

The rate of change of its velocity with respect to time

Answer

The rate of change of its speed

Answer

The rate of change of its direction

Answer

The rate of change of its displacement

Question 43

The Reynolds number is a dimensionless quantity that represents the:

Accepted Answer

Ratio of inertial forces to viscous forces

Answer

Ratio of viscous forces to inertial forces

Answer

Ratio of inertial forces to pressure forces

Answer

Ratio of pressure forces to viscous forces

Question 44

The Navier-Stokes equations describe:

Accepted Answer

The motion of viscous fluids

Answer

The flow of gases

Answer

The flow of solids

Answer

The motion of inviscid fluids

Question 45

For a velocity field V = (u, v, w), the differential equation of the streamline passing through the point (x0, y0, z0) is given by:

Accepted Answer

dx/u = dy/v = dz/w

Answer

dx/u = dy/v = dz/w = dt/t

Answer

dx/u = dy/w = dz/v

Answer

dx/v = dy/u = dz/w

Question 46

Which type of flow is characterized by constant velocity throughout the fluid?

Accepted Answer

Uniform flow

Answer

Laminar flow

Answer

Turbulent flow

Question 47

The circulation around a closed curve in a fluid is a measure of:

Accepted Answer

Line integral of tangential velocity

Answer

Surface integral of vorticity

Answer

Area integral of normal velocity

Answer

Volume integral of velocity

Question 48

The vorticity of a fluid is a measure of:

Accepted Answer

Local rotation of fluid particles

Answer

Acceleration of fluid particles

Answer

Linear velocity of fluid particles

Question 49

Which of the following is a necessary condition for irrotational flow?

Accepted Answer

Zero vorticity

Answer

Viscous flow

Answer

Compressible flow

Answer

Incompressible flow

Question 50

The velocity potential for an incompressible, inviscid flow is:

Accepted Answer

A scalar function whose gradient yields the velocity

Answer

A tensor function whose curl yields the velocity

Answer

A vector function whose divergence yields the velocity

Question 51

The stream function for an incompressible, inviscid flow is:

Accepted Answer

A scalar function whose gradient yields the velocity perpendicular to the flow direction

Answer

A tensor function whose curl yields the velocity

Answer

A vector function whose divergence yields the velocity