FLUID MECHANICS
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.
C. A and B above 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 above are correct D. Cheap and easily available
Real or ideal
For computation convenience, fluids are usually classed as:
C. Negligible
For high speed flows, the potential energy of fluids are: A. Positive B. Negative C. Negligible D. None of these
above the center of gravity
For stable equilibrium of floating body its metacenter should be:
Increases
For supersonic flow, the pressure of fluid must decrease as the fluid flow area of the duct.
Decreases
For supersonic flow, the pressure of fluid must increase as the fluid flow area of the duct:
Moody diagram
Friction factor for both laminar and turbulent flows can be found plotted in a
D. hysteresis
All of the following can be characteristics of fluids except_________. A. kinematic viscosity B. surface tension C. bulk modulus D. hysteresis
D. 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
Steady flow
At any instant, if the number of particles passing every cross-section of the stream is the same, the flow is said to be:
Conservation of energy equation
Bernoulli's equation is s/an ___________.
Specific gravity liquids
Hydrometer is used to find out
No flow takes place
In a nozzle if back pressure is same as inlet pressure; then_______________.
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:
Sonic velocity
Is the velocity at which an infinitesimal small pressure wave travels through a medium.
Mach number
It is the ratio of the actual velocity of the fluid to the velocity of sound.
High speed flow
Kinetic energy is not neglected in calculations of:
Shape
Liquids and gases take the following characteristic(s) of their contents.
D. 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
Boyle's law
McLeod gauge used for low pressure measurement operates on the principle of _________.
Froude's number
Neglecting the forces due to inertia, gravity and frictional resistance, the design of a channel can be made by comparing
In hydraulic structure with regulation provision
Orifice refers to an opening
4-5 m/s
Permissible velocity of water flowing through concrete tunnel, is generally
One-third of the total head supplied
Power transmitted through a pipe is maximum when the loss of head due to friction is:
Cohesion
Property of a fluid whereby its own molecules are attracted is known as ________.
Pressure
Refers to the compressibility of a fluid, the fractional change in fluid volume per unit change in fluid.
No load speed when governor mechanism fails
Running away speed of a Pelton wheel gives:
10 times poise
SI unit of viscosity is:
D. 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:
Throat
The Mach number is unity or one at the location of smallest flow area, called the:
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 __________.
Conservation of mass
The continuity equation is applicable to:
States that energy is constant everywhere in the fluid
The continuity equation of an ideal fluid flow.
None of the terms are interchangeable
The difference between stagnation pressure and total pressure is:
D. The sum of pressure energy and potential energy
The hydraulic grade line of a pipe denotes which of the following? A. Total energy B. Pressure energy C. Potential energy D. The sum of pressure energy and potential energy
The ratio of the area to the wetted perimeter
The hydraulic radius of noncircular pipe is:
C. 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
First slowly and then steeply
The length of mercury column at a place at an altitude will change with respect to that at ground in:
Displaced volume of the fluid
The line action of the buoyant forces always acts through the centroid of the ______.
The Darcy equation
The most common method for calculating frictional energy loss for laminar flowing fluids in noncircular pipe is:
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:
The Darcy friction factor
The parameter f in the expression for head-loss is
Velocity
The pilot tube is a device used for measurement of
Down in the direction of the flow
The presence of a minor loss in the energy grade line will cause the line to slope:
Down in the direction of the flow
The presence of friction in the energy grade line will always cause the line to slope
Down in the direction of the flow
The presence of friction in the hydraulic grade line will always cause the line to slope:
The sum of the individual pressures
The pressure at a given depth due to several immiscible liquids is:
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:
Increases
The pressure decreases as the temperature and velocity increases while the fluid velocity and Mach number:
Hydraulic mean depth
The ratio of cross-sectional area of flow to the wetted perimeter is:
Hydraulic radius
The ratio of the area to the wetted penmeter is known as __________.
Barometric height relationship
The relationship between pressure and altitude in the atmosphere is given by the:
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:
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
The conservation of mass
The stream function is a useful parameter in describing_____________.
Hydraulics
The study of the practical laws of fluid flow and the resistance of open pipes and channels.
Less than the local speed of sound
The term subsonic flow refers to a flowing gas with a speed:
Half time
The time required for half a quantity of radioactive particles to decay (disintegrate) is called its_____________.
Of no practical importance to designers
The upper critical Reynolds number for pipe flow is:
Less
The value of coefficient of discharge in comparison to coefficient of velocity is found to be_______.
Maximum
The velocity of a fluid particle at the center of the pipe section is______.
Adhesion
The volumetric change of the fluid caused by a resistance is called ________.
Adhesion
The volumetric change of the fluid caused by a resistance is called:
D. 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
Reduce the energy of flow
What is the use of a Hydraulic jump?
At a distance approximately ½ the diameter of the orifice
Where is vena contracta most likely loacated?
D. 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
D. Pilot 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. Pilot tube
A. 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
B. Gas
Which of the following is an example of Newtonian fluid? A. Motor oils B. Gas C. Paints D. Clay slurries
B. Speed of sound
Which of the following is considered as an important parameter in the study of compressible flow? A. Speed of fluid B. Speed of sound C. Speed of light D. Speed of fluid flow
C. 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. Its acts normal to a surface C. It is a shear stress D. It is linear with depth
D. Experience of eddy current 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 current and turbulence
A. 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
B. 100 kg/𝑚3
Which of the following is not the mass density of water? A. 62.5 lbm/𝑓𝑡3 B. 100 kg/𝑚3 C. 1 g/𝑐𝑚3 D. 1 kg/L
Vector difference of two velocities
Which of the following is relative velocity?
B. 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
A. 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/𝑐𝑚2 D. 75.0 cm of Hg
Pressure
Compressibility of a fluid relates the fractional change in fluid volume per unit change in fluid.
An electron will not be ejected
If the energy of the incident photon is less than the work function:
Laminar
If the fluid travels parallel to the adjacent layers and the paths of individual particles do not cross, the fluid is said to be:
Dead storage
What do you call the lowest portion to storage basin from where the water is not drawn?
Hydrostatic pressure
What do you call the pressure which the fluid exerts on an immersed object or container walls?
Increases rapidly
What happens to the velocity of fluid after passing the throat although the flow area
Velocity
What is measured by a Pitot tube?
The ratio of the area of vena contracta to the area of the orifice
What is the coefficient of contraction?
More than 200 kg/cm2
What is the critical pressure of water?
Kinetic energy
What is the difference between the energy grade line and the hydraulic grade line?
D. 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 module D. Thermal conductivity
Low head axial flow turbine
A Kaplan turbine is
Kinetic energy and static pressure
A pilot tube can be used to measure fluid velocity as described by the Bernoulli's equation and the relationship between:
Has no velocity component tangent to it
An equipotential line is one that:
Is frictionless and incompressible
An ideal fluid is one that:
Below the centroid
Center of pressure on an inclined plane has ___.
Below the centroid
Center of pressure on an inclined plane lies:
Dynamic viscosity / kinematic viscosity
Density in term of viscosity is:
Both friction and minor losses
Discharge losses through orifice are due to:
A. 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
A / Pw
If A is the cross-sectional area of the flow and Pw is the wetted perimeter of a pipe, then what is the hydraulic depth. Hd?
E = mDQ
If Q is the volume in gallon; D is height or elevation in ft. and m is weight in lbs. per gallon, what is the desired energy to lift the water from lower to higher elevation?
Supersonic travel
If the Mach number is greater than 1 but lesser than 5, what is the standard classification of the travel?
A. 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
Height above a chosen datum, density, internal energy, pressure and velocity of flow
The energy of a fluid flowing at any section in a pipeline is a function of:
D. 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
Nuclear energy
The extended Bernoulli equation includes all of the following terms except:
Archimedes' principle
The fact the buoyant force on a floating object equal to the weight of the water displaced is:
Equal to 1
The flow is called sonic when Mach number is:
Greater than 1
The flow is supersonic when Mach no. is:
M = 1
The flow is transonic when
Less than unity
The flow of the convergent section of a nozzle is always subsonic. If the flow is subsonic then the Mach number is:
Supersonic on one side and sub-sonic on the other side
The flow on two sides of a normal shock wave is called___________.
Gravity, pressure and viscous
The fluid forces taken into consideration in the Navier Strokes equation are:
Less than 1
The following flow is sub-sonic when Mach no. is:
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?
C. 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
The spatial derivative of velocity
Viscosity for a fluid is defined as the constant of proportionality between shear stress and what other variable?
Having partially full flow
Weir refers to an opening
C. Reynolds number and relative roughness
Which of the following parameters determine the friction factor of turbulent flow in a rough pipe? A. Froude number and relative roughness B. Froude number and Mach number C. Reynolds number and relative roughness D. Mach number and relative roughness
Viscosity index
Which of the following refers to the measure of a fluid's sensitivity to changes in viscosity with changes in temperature?
D. 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
Atmospheric pressure
Which of the following statements about gauge pressure is most correct? Gauge pressure are measured relative to _________.
Hysteresis losses
Which of the following terms does not appear in the steady flow energy equation (the extended Bernoulli's equation)?
D. Pelton wheel
Which of the following turbine is different from the others? A. Fourneyron turbine B. Francis turbine C. Kaplan turbine D. Pelton wheel
D. Kaplan turbine
Which of the following turbine is different from the others? A. Pelton wheel B. Banki turbine C. Jonval turbine D. Kaplan turbine
