PIPE | Fluid Mechanics

an electron will not be ejected

If the energy of the incident photon is less than the work function:

A. an electron will be ejected

B. more than one electron will be ejected

C. an electron will not be ejected

D. less than one electron will be ejected

Increases

For supersonic flow, the pressure of fluid must decrease as the fluid flow area of the duct

A. Increases

B. Decreases

C. Remain the same

D. None of these

Dynamic viscosity/kinematic viscosity

Density in terms of viscosity is

A. Kinematic viscosity/dynamic viscosity

B. Dynamic viscosity/kinematic viscosity

C. Kinematic viscosity x dynamic viscosity

D. None of the above

Shape

Liquids and gases take the following characteristic(s) of their contents

A. Volume

B. Shape

C. Shape and volume

D. Neither shape nor volume

A and B are correct

Alcohol finds use in manometers as:

A. It provides a suitable meniscus for the inclined tube

B. Its density being less can provide longer length for a pressure difference, thus more accuracy can be obtained

C. A and B are correct

D. Cheap and easily available

Shear stress is proportional to rate of strain

Which of the following statements about a Newtonian fluid is most accurate?

A. Shear stress is proportional to strain

B. Viscosity is zero

C. Shear stress is multi-valued

D. Shear stress is proportional to rate of strain

When there is no motion of one fluid layer relative to an adjacent layer

The normal stress is the same in all directions at a point in fluid:

A. Independent to the motion of one fluid layer relative to an adjacent layer

B. When there is no motion of one fluid layer relative to an adjacent layer

C. Only if the fluid is frictionless

D. Only if fluid is frictionless and incompressible

It is a shear stress

Which of the following is not a characteristic of fluid pressure?

A. It is the same in all directions at a point in the fluid

B. It acts normal to a surface

C. It is a shear stress

D. It is linear with depth

First slowly and then steeply

The length of mercury column at a place at an altitude will change with respect to that at a ground in:

A. A linear relation

B. A parabolic relation

C. Will remain constant

D. First slowly and then steeply

Biot number

All of the following dimensionless parameters are applicable to fluid flow problems except the ________

A. Reynolds number

B. Froude number

C. Mach number

D. Biot number

all of the above

Mass density of liquid (ρ) is given by which of the following?

A. ρ = Mass / volume

B. ρ = metric slug / m²

C. ρ = kg sec² / m⁴

D. all of the above

Thermal conductivity

The speed of sound in all fluid is most closely related to all of the following properties except _________.

A. Compressibility

B. Density

C. Bulk modulus

D. Thermal conductivity

All of the above

Under which condition, the specific weight of water is 1000 kg/m3?

A. At normal pressure of 760 mm

B. At 4°C temperature

C. At mean sea level

D. All of the above

Hysteresis

All of the following can be characteristics of fluids except ________

A. Kinematic viscosity

B. Surface tension

C. Bulk modulus

D. Hysteresis

Pitot tube

Which of the following can be used to measure the flow of water in a pipe of diameter 3000 mm?

A. Venturimeter

B. Rotameter

C. Nozzle

D. Pitot tube

The sum of the individual pressures

The pressure at a given depth due to several immiscible liquids is:

A. The average of the individual pressures

B. The sum of the individual pressures

C. Independent of the individual pressures

D. Unknown

All of the above conditions are together

The equation of continuity of flow is applicable if:

A. The flow is one dimensional

B. The flow is steady

C. The velocity is uniform over the cross – section

D. All of the above conditions are together

At every point the velocity vector is identical in magnitude and direction for any given instant

Uniform flow takes place when:

A. Conditions remain unchanged with time at any point

B. Rate of change of velocity of fluid is zero

C. At every point the velocity vector is identical in magnitude and direction for any given instant

D. The change in transverse direction is zero

States that energy is constant everywhere in the fluid

The continuity equation of ideal fluid flow:

A. States that the net rate of in – flow into any small volume must be zero

B. Applies to irrotational flow only

C. States that the energy remains constant along streamline

D. States that energy is constant everywhere in the fluid

Kinetic energy and static pressure

A pitot tube can be used to measure fluid velocity as described by the Bernoulli’s equation and the relationship between:

A. Kinetic energy and static pressure

B. Fluid pressure and height of the fluid

C. Fluid pressure and impact energy

D. Pressure and momentum

6.4 m above the hydraulic gradient

In order to avoid vaporization in the pipe line, the pipe line over the ridge is laid in such a way that it is not more than:

A. 2.4 m above the hydraulic gradient

B. 6.4 m above the hydraulic gradient

C. 10.0 m above the hydraulic gradient

D. 5.0 m above the hydraulic gradient

The conservation of mass

The stream function is a useful parameter in describing _______.

A. The conservation of mass

B. The conservation of momentum

C. The conservation of energy

D. The equation of state

Negligible

For high speed flows, the potential energy of the fluids are:

A. Positive

B. Negative

C. Negligible

D. None of these

Boyle’s law

McLeod gauge used for low pressure measurement operates on the principle of ______.

A. Gas law

B. Boyle’s law

C. Charles law

D. Pascal’s law

Low head axial flow turbine

A Kaplan turbine is

A. A high head mixed flow turbine

B. An impulse turbine, inward flow

C. A reaction turbine, outward flow

D. Low head axial flow turbine

The Darcy equation

The most common method for calculating frictional energy loss for laminar flowing fluids in noncircular pipes is:

A. The Darcy equation

B. The Hagan – Poisevill equation

C. The Hazen – Williams equation

D. The Swamee – Jin equation

The Darcy friction factor

The parameter f in the expression for head-loss is

A. The fraction of flow that is totally turbulent

B. The Darcy friction factor

C. The height of the roughness scale in turbulent flow

D. The static coefficient of friction

Psychrometric chart

Friction factor for both laminar and turbulent flow can be found plotted in a

A. Steam table

B. Psychrometric chart

C. Moody diagram

D. Mollier diagram

Vector difference of two velocities

Which of the following is relative velocity?

A. The difference between two velocities

B. Average velocity

C. Sum of two velocities

D. Vector difference of two velocities

33 inch Hg

Which of the following is the highest head?

A. 33 inch Hg

B. 31.0 ft. water

C. 1.013 kg kg/cm3

D. 75.0 cm of Hg

Above the center of gravity

For stable equilibrium of floating body its metacenter should lie:

A. Below the center of gravity

B. Below the center of buoyancy

C. Above the center of buoyancy

D. Above the center of gravity

Below the centroid

Center of pressure on an inclined plane lies _______

A. At the centroid

B. Above the centroid

C. Below the centroid

D. At metacenter

Displaced volume of the fluid

The line of action of the buoyant forces always acts through the centroid of the _______.

A. Submerged body

B. Volume of the floating body

C. Volume of the fluid vertically above the floating body

D. Displaced volume of the fluid

The sum of pressure energy and potential energy

The hydraulic grade line of a pipeline denotes which of the following?

A. Total energy

B. Pressure energy

C. Potential energy

D. The sum of pressure energy and potential energy

Total energy

The energy grade line of a pipeline denotes which of the following

A. Total energy

B. Pressure energy

C. Potential energy

D. The sum of pressure energy and potential energy

Down in the direction of the flow

The presence of friction in the energy grade line will always cause the line to slope

A. Down in the direction of the flow

B. Upward in the direction of the flow

C. Level (no slop)

D. There is no effect of friction on the energy grade line

Velocity

The pitot tube is a device used for measurement of

A. Pressure

B. Flow

C. Velocity

D. Discharge

Specific gravity of liquids

Hydrometer is used to find out

A. Specific gravity of liquids

B. Specific gravity of solids

C. Specific gravity of gases

D. Relative humidity

Gravity, pressure, and viscous

The fluid forces taken into consideration in the Navier Stokes equation are:

A. Gravity, pressure, and viscous

B. Gravity, pressure and turbulent

C. Pressure, viscous and turbulent

D. Gravity, viscous and turbulent

4 – 5 m/s

Permissible velocity of water flowing through concrete tunnel is generally

A. 4 – 5 m/s

B. 10 – 12 m/s

C. 13 – 16 m/s

D. 20 m/s

In hydraulic structure with regulation provision

Orifice refers to an opening

A. With closed perimeter and of regular form through which water flows

B. With prolonged sides having length of 2 to 3 diameters of opening in thick wall

C. With partially full flow

D. In hydraulic structure with regulation provision

Less

The value of coefficient of discharge in comparison to coefficient of velocity is found to be _____.

A. More

B. Less

C. Same

D. More/less depending on the flow

With partially full flow

Wier refers to an opening

A. Having closed perimeter and of regular form through which water flows

B. Having prolonged sides with length of 2 to 3 diameters of opening in thick wall

C. With partially full flow

D. In hydraulic structure with regulation provision

One – third of the total head supplied

Power transmitted through a pipe is maximum when the loss of head due to friction is:

A. One – half of the total head supplied

B. One – third of the total head supplied

C. One – fourth of the total head supplied

D. Equal to the total head supplied

No flow takes place

In a nozzle if back pressure is same as inlet pressure; then ______.

A. No flow takes place

B. Maximum flow takes place

C. Flow becomes subsonic in diverging section

D. Flow becomes supersonic in converging as well as supersonic section

Supersonic on one side and sub-sonic on the other side

The flow on two sides a normal shock wave is called ______.

A. Sonic

B. Sub-sonic

C. Supersonic

D. Supersonic on one side and sub-sonic on the other side

Principle of conservation of energy

Which of the following is the basic of Bernoulli’s law for fluid flow?

A. Continuity equation

B. Principle of conservation of energy

C. Fourier’s law

D. Principle of conservation of mass

It is a shear stress

Which of the following is NOT a characteristic of fluid pressure?

A. It is a shear stress

B. It is the same in all directions at a point in the fluid

C. It acts normal to a surface

D. It is linear with depth

Pressure

Refers to the compressibility of a fluid, the fractional change in fluid volume per unit change in fluid.

A. Viscosity

B. Bulk modulus

C. Density

D. Pressure

Kinetic energy and static pressure

A pitot tube can be used to measure fluid velocity as described by the Bernoulli’s equation and the relationship between:

A. Kinetic energy and static pressure

B. Fluid pressure and static pressure

C. Fluid pressure and impact energy

D. Pressure and momentum

Hydraulic radius

The ratio of the area to the wetted perimeter is known as _______.

A. Flow factor

B. Hydraulic radius

C. Kutter’s C

D. Value of k in Darcy – Weisbach formula

The ratio of the area of vena contracta to the area of the orifice

What is the coefficient of contraction?

A. The ratio of the area of vena contracta to the area of the orifice

B. The ratio of actual discharge to the theoretical discharge

C. The ratio of the actual velocity to the theoretical velocity

D. The ratio of the effective head to the actual head

At a distance approximately 1/2 the diameter of the orifice

Where is the vena contracta most likely located?

A. At the orifice

B. At a distance approximately 1/2 the diameter of the orifice

C. At a distance approximately equal to the diameter of the orifice

D. At a distance approximately twice the diameter of the orifice

Fluid

A substance that is able to flow and yields to any force tending to change its shape without changing its volume such as water and air.

A. Fluid

B. Flux

C. Gas oil

D. Water gas

Maximum

The velocity of a fluid particle at the center of the pipe section is ________.

A. Maximum

B. Minimum

C. Average

D. Logarithmic average

Increases

For supersonic flow, the pressure of fluid must increase as the fluid flow area of the duct:

A. Increases

B. Decreases

C. Constant

D. None of these

It may occur owing to cohesion when the fluid is at rest

Which is incorrect statement regarding apparent shear forces.

A. It can never be found in frictionless fluid regardless of its motion

B. It can never be found when the fluid is at rest

C. It depends upon cohesive forces

D. It may occur owing to cohesion when the fluid is at rest

Half life

The time required for half a quantity of radioactive particles to decay (disintegrate) is called its ______.

A. Average life

B. Median life

C. Time constant

D. Half life

10 times poise

SI unit of viscosity is:

A. 10 times poise

B. 9.81 times poise

C. 1/9.81 times poise

D. 1/10 times poise

Real or ideal

For computation convenience, fluids are usually classed as:

A. Rotational or irrotational

B. Real or ideal

C. Laminar or turbulent

D. Newtonian or non-Newtonian

Kinetic viscosity

Which of the following is not a dimensionless parameter?

A. Kinetic viscosity

B. Weber number

C. Darcy Weisbach friction factor

D. Froude number

Experience of eddy currents and turbulence

Which of the following is not a characteristic of real fluids?

A. Finite viscosity

B. Non-uniform velocity distributions

C. Compressibility

D. Experience of eddy currents and turbulence

100 kg/m3

Which of the following is not the mass density of water?

A. 62.5 lb_m/ft³

B. 100 kg/m³

C. 1 g/cm³

D. 1 kg/L

of no practical importance to designers

The upper critical Reynolds number for pipe flow is:

A. of no practical importance to designers

B. Always used to design pipes for strength

C. The number at which turbulent flow changes over to laminar flow

D. The number at which laminar flow changes over to turbulent flow

Adhesion

The volumetric change of the fluid caused by a resistance is called _______.

A. Volumetric strain

B. Volumetric index

C. Compressibility

D. Adhesion

Pressure

Compressibility of a fluid relates the fractional change in fluid volume per unit change in fluid.

A. Temperature

B. Density

C. Pressure

D. Viscosity

Cohesion

Property of a fluid whereby its own molecules are attracted is known as ______.

A. Adhesion

B. Cohesion

C. Pressure

D. Viscosity

Less than the local speed of sound

The term subsonic flow refers to a flowing gas with a speed:

A. Less than the local speed of sound

B. Equal to the speed of sound

C. Greater than the speed of sound

D. Much greater than the speed of sound

Viscous and is in motion

The pressure at a point in a fluid will not be same in all the directions if the fluid is:

A. Viscous

B. Viscous and static

C. Inviscous and in motion

D. Viscous and is in motion

The hydrostatic paradox

The statement that “the hydrostatic pressure a fluid exerts on an immersed object or on container walls is a function only of fluid depth” is

A. The perfect gas law

B. D’Alembert’s paradox

C. The hydrostatic paradox

D. Boyles law

Conservation of energy equation

Bernoulli’s equation is s/an _______.

A. Momentum equation

B. Conservation of energy equation

C. Conservation of mass equation

D. Equation of state

Is frictionless and incompressible

An ideal fluid is one that:

A. Is very viscous

B. Obeys Newton’s law of viscosity

C. Is assumed in problems in conduit flow

D. Is frictionless and incompressible

Barometric height relationship

The relationship between pressure and altitude in the atmosphere is given by the:

A. Perfect gas law

B. Conservation of mass

C. Barometric height relationship

D. First law of thermodynamics

Archimedes’ principle

The fact the buoyant force on a floating object equal to the weight of the water displaced is:

A. Bernoulli’s law

B. Archimedes’ principle

C. The law of diminishing returns

D. The conservation of mass

Hysteresis losses

Which of the following terms does not appear in the steady flow energy equation (the extended Bernoulli’s equation)?

A. Kinetic energy

B. Potential energy

C. Friction losses

D. Hysteresis losses

Froude’s number

Neglecting the forces to inertia, gravity and frictional resistance, the design of a channel can be made by comparing

A. Weber number

B. Reynolds number

C. Froude’s number

D. Prant’l number

None of the terms are interchangeable

The difference between stagnation pressure and total pressure is:

A. Due to height differences

B. Due to fluid kinetic energy

C. None of the terms are interchangeable

D. Important only in supersonic flow

A parabolic velocity profile

Fully turbulent flow in a pipe is characterized by all of the following except:

A. A parabolic velocity profile

B. A momentum exchange due to fluid masses rather than molecules

C. A maximum velocity at the fluid center line

D. A 1/7 velocity profile

Pipe roughness

The laminar friction factor of fluid flowing through a pipe is a function of all of the following except:

A. Fluid velocity

B. Pipe diameter

C. Pipe roughness

D. Reynolds number

Conservation of mass

The continuity equation is applicable to:

A. Viscous unviscous fluids

B. Compressibility of fluids

C. Conservation of mass

D. Steady unsteady flow

A. 4s/wd

The rise or fall of head ‘h’ in a capillary tube of diameter ‘d’ and liquid surface tension ‘s’ and specific weight ‘w’ is given by:

A. 4s/wd

B. 4ds/w

C. 4wd/s

D. 4ws/d

Hydraulics

The study of the practical laws of fluid flows and the resistance of open pipes and channels.

A. Fluid mechanics

B. Hydraulics

C. Aerodynamics

D. Thermodynamics

Pelton wheel

Which of the following turbine is different from the others?

A. Fourneyron turbine

B. Francis turbine

C. Kaplan turbine

D. Pelton wheel

No load speed when governor mechanism fails

Running away speed of a Pelton wheel gives:

A. Actual operating speed

B. No load speed

C. Full load speed

D. No load speed when governor mechanism fails

Kaplan turbine

Which of the following turbine is different from the others?

A. Pelton wheel

B. Banki turbine

C. Jonval turbine

D. Kaplan turbine

Hydraulic diameter (the equivalent diameter)

The characteristic length of the Reynold’s number used to calculate the friction in noncircular full running pipes is based on the ________.

A. Run length

B. Pipe length

C. Hydraulic diameter (the equivalent diameter)

D. Wetted circumference

The ratio of the area to the wetted perimeter

The hydraulic radius of noncircular pipe is:

A. The square root of the flow area

B. The ratio of the area to the wetted perimeter

C. The radius of a pipe of equivalent area

D. None of the above

Air flowing supersonically

The Darcy equation can be used for all liquids and flows except:

A. Water

B. Alcohol

C. Gasoline

D. Air flowing supersonically

Empirical data

The Hazen – Williams formula for head loss due to friction is based upon:

A. Rigorous mathematical derivation

B. Empirical data

C. Semi-empirical analysis

D. Serendipity

Nuclear energy

The extended Bernoulli’s equation includes all of the following terms except:

A. Potential energy

B. Kinetic energy

C. Nuclear energy

D. Friction losses

Has no velocity component tangent to it

An equipotential line is one that:

A. Has no velocity component tangent to it

B. Has no uniformly varying dynamic pressure

C. Has no velocity component normal to it

D. Exists in case of rotational flow

Reduce the energy of flow

What is the use of a Hydraulic jump?

A. Increase the flow rate

B. Reduce the flow rate

C. Reduce the velocity of flow

D. Reduce the energy of flow

Dead storage

What do you call the lowest portion to storage basin from where the water is not drawn?

A. Bottom storage

B. Sub soil storage

C. Spring reserve

D. Dead storage

Down in the direction of the flow

The presence of friction in the hydraulic grade line will always cause the line to slope:

A. Down in the direction of the flow

B. Upward in the direction of the flow

C. Level (no slope)

D. There is no effect of friction on the energy grade

Down in the direction of the flow

The presence of a minor loss in the energy grade line will cause the line to slope:

A. Down in the direction of the flow

B. Upward in the direction of the flow

C. Vertically downward

D. There is no effect of friction on the energy grade line

Hydrostatic pressure

What do you call the pressure which the fluid exerts on an immersed object or container walls?

A. Normal pressure

B. Standard liquid pressure

C. Hydrostatic pressure

D. Gage pressure

The spatial derivative of velocity

Viscosity for a fluid is defined as the constant of proportionality between shear stress and what other variable?

A. The spatial derivative of velocity

B. The time derivative of pressure

C. The time derivative of density

D. The spatial derivative of density

Laminar flow

What is the classification of the fluid flow if the fluid travels parallel to the adjacent layers and the paths of the individual particles do not cross each other?

A. Steady flow

B. Laminar flow

C. Uniform flow

D. Turbulent flow

Viscosity index

Which of the following refers to the measure of a fluid’s sensitivity to changes in viscosity with changes in temperature?

A. Viscosity index

B. Coefficient of viscosity

C. Viscosity ratio

D. Viscosity factor

Supersonic travel

If the Mach number is greater than 1 but lesser than 5, what is the standard classification of the travel?

A. Transonic travel

B. Subsonic travel

C. Hypersonic travel

D. Supersonic travel