HYDRAULICS OBJECTIVE QUESTIONS Flashcards by Nathalie Encinas

fluid is a substance that _____

A. cannot be subjected to shear forces
B. always expands until it fills any container
C. has the same shear stress at a point regardless of its motion
D. cannot remain at rest under action of any shear force

D. cannot remain at rest under action of any shear force

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density of water is maximum at _____

A. 0°C
B. 4°C
C. 100°C
D. 20°C

B. 4°C

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property of a fluid by which its own molecules are attracted is called _____

A. adhesion
B. cohesion
C. viscosity
D. surface tension

B. cohesion

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property of a fluid by which molecules of different kinds of fluids are attracted to each other is called _____

A. adhesion
B. cohesion
C. viscosity
D. surface tension

A. adhesion

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the normal stress in a fluid will be constant in all directions at a point only if _____

A. it is incompressible
B. it has zero viscosity
C. it is frictionless
D. it is at rest

D. it is at rest

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specific weight of sea water is more that of pure water because it contains _____

A. dissolved air
B. dissolved salt
C. suspended matter
D. all of the above

D. all of the above

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free surface of a liquid tends to contract to the smallest possible area due to force of _____

A. surface tension
B. viscosity
C. friction
D. cohesion

A. surface tension

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a liquid would wet the solid, if adhesion forces as compared to cohesion forces are _____

A. less
B. more
C. equal
D. less at low temperature and more at high temperature

B. more

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barometer is used to measure _____

A. pressure in pipes, channels etc.
B. atmospheric pressure
C. very low pressure
D. difference of pressure between two points

B. atmospheric pressure

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manometer is used to measure _____

A. pressure in pipes, channels etc.
B. atmospheric pressure
C. very low pressure
D. velocity in pipes

A. pressure in pipes, channels etc.

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if cohesion between molecules of a fluid is greater than adhesion between fluid and glass, then the free level of fluid in a dipped glass tube will be _____

A. higher than the surface of liquid
B. the same as the surface of liquid
C. lower than the surface of liquid
D. unpredictable

C. lower than the surface of liquid

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when a fluid is subjected to resistance, it undergoes a volumetric change due to _____

A. cohesion
B. strain
C. compressibility
D. adhesion

C. compressibility

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liquids transmit pressure equally in all the directions; this is according to _____

A. Boyle’s law
B. Archimedes principle
C. Pascal’s law
D. Newton’s formula

C. Pascal’s law

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the rise or depression of liquid in a tube due to surface tension with an increase in size of tube will _____

A. increase
B. remain unaffected
C. may increase or decrease depending on the characteristics of liquid
D. decrease

D. decrease

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mercury is often used in barometer because _____

A. it is the best liquid
B. the height of barometer will be less
C. its vapor pressure is so low that it may be neglected
D. both (b) and (c)

D. both (b) and (c)

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which of the following is the correct relation between centroid (cg) and the center of pressure (cp) of a plane submerged in a liquid?

A. cg is always below cp
B. cp is always below cg
C. cg is either at cp or below it
D. cp is either at cg or below it

D. cp is either at cg or below it

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the point in the immersed body through which the resultant pressure of the liquid may be taken to act is known as _____

A. metacenter
B. center of pressure
C. center of buoyancy
D. center of gravity

B. center of pressure

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the total pressure force on a plane area is equal to the area multiplied by the intensity of pressure at the centroid, if _____

A. the area is horizontal
B. the area is vertical
C. the area is inclined
D. all of the above

D. all of the above

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choose the wrong statement

A. the horizontal component of the hydro-static force on any surface is equal to the normal force on the vertical projection of the surface

B. the horizontal component acts through the center of pressure for the vertical projection

C. the vertical component of the hydrostatic force on any surface is equal to the weight of the volume of the liquid above the area

D. the vertical component passes through the center of pressure of the volume

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center of pressure on an inclined plane is _____

A. at the centroid
B. above the centroid
C. below the centroid
D. at metacenter

C. below the centroid

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can center of pressure for a vertical plane submerged surface be ever be above center of gravity?

A. yes
B. no
C. it can be above in cases where the surface height is very large
D. none of the mentioned

B. no

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in a vertically submerged plane surface, pressure at every point remains same

A. true
B. false

B. false

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for an inclined plate the pressure intensity at every point differs

A. true
B. false

A. true

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the magnitude of total pressure and center of pressure is independent on the shape of the submerged plane surface

A. true
B. false

B. false

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what is the variation of total pressure with depth for any submerged surface if we neglect variation in the density? A. linear B. parabolic C. curvilinear D. logarithmic

A. linear

the resultant upward pressure of a fluid on a floating body is equal to the weight of the fluid displaced by the body; this definition is according to _____ A. equilibrium of a floating body B. Archimedes’ principle C. Bernoulli's theorem D. metacentric principle

B. Archimedes’ principle

the resultant upward pressure of the fluid on an immersed body is called _____ A. upthrust B. buoyant force C. center of pressure D. all the above

B. buoyant force

what is the principal cause of action of buoyant force on a body submerged partially or fully in fluid? A. displacement of fluid due to submerged body B. development of force due to dynamic action C. internal shear forces mitigating external forces D. none of the mentioned

A. displacement of fluid due to submerged body

the center of gravity of the volume of the liquid displaced by an immersed body is called _____ A. metacenter B. center of pressure C. center of buoyancy D. center of gravity

C. center of buoyancy

the horizontal component of buoyant force is _____ A. negligible B. same as buoyant force C. zero D. none of the above

C. zero

the line of action of the buoyant force acts through the _____ A. centroid of the volume of fluid vertically above the body B. center of the volume of floating body C. center of gravity of any submerged body D. centroid of the displaced volume of fluid

D. centroid of the displaced volume of fluid

choose the wrong statement A. any weight, floating or immersed in a liquid, is acted upon by a buoyant force B. buoyant force is equal to the weight of the liquid displaced C. the point through which buoyant force acts, is called the center of buoyancy D. center of buoyancy is located above the center of gravity of the displaced liquid

D. center of buoyancy is located above the center of gravity of the displaced liquid

according to the principle of buoyancy a body totally or partially immersed in a fluid will be lifted up by a force equal to _____ A. the weight of the body B. more than the weight of the body C. less than the weight of the body D. weight of the fluid displaced by the body

D. weight of the fluid displaced by the body

how can relatively denser object be made to float on the less dense fluid? A. by altering the shape B. by altering the forces acting on the object C. by altering the shear forces acting on the object D. none of the mentioned

A. by altering the shape

the conditions for the stable equilibrium of a floating body are _____ A. the metacenter should lie above the center of gravity B. the center of buoyancy and the center of gravity must lie on the same vertical line C. a righting couple should be formed D. all the above

D. all the above

metacentric height is given as the distance between _____ A. the center of gravity of the body and the meta center B. the center of gravity of the body and the center of buoyancy C. the center of gravity of the body and the center of pressure D. center of buoyancy and metacenter

A. the center of gravity of the body and the meta center

metacenter is the point of intersection of _____ A. vertical upward force through cg of body and center line of body B. buoyant force and the center line of body C. midpoint between e.g. and center of buoyancy D. all of the above

B. buoyant force and the center line of body

when a body floating in a liquid, is displaced slightly, it oscillates about _____ A. cg of body B. center of pressure C. center of buoyancy D. metacenter

D. metacenter

when the ship’s metacenter and center of gravity coincide at same point then the vessel is said to be in _____ A. equilibrium B. stable equilibrium C. unstable equilibrium D. neutral equilibrium

D. neutral equilibrium

energy gradient line takes into consideration _____ A. potential and kinetic heads only B. potential and pressure heads only C. kinetic and pressure heads only D. potential, kinetic and pressure heads

D. potential, kinetic and pressure heads

which of the following is true? A. EGL always drops in the direction of flow B. EGL always rises in the direction of flow C. EGL always remains constant in the direction of flow D. EGL may or may not change in the direction of flow

A. EGL always drops in the direction of flow

which of the following is true? A. HGL will never be above EGL B. HGL will never be under EGL C. HGL will never coincide with EGL D. HGL will may or may not be above EGL

A. HGL will never be above EGL

the vertical intercept between EGL and HGL is equal to _____ A. pressure head B. potential head C. kinetic head D. Piezometric head

C. kinetic head (or velocity head)

the slope of HGL will be _____ A. greater than that of EGL for a pipe of uniform cross-section B. smaller than that of EGL for a pipe of uniform cross-section C. equal than that of EGL for a pipe of uniform cross-section D. independent of that of EGL for a pipe of uniform cross-section

C. equal than that of EGL for a pipe of uniform cross-section

equation of continuity is based on the principle of conservation of _____ A. mass B. energy C. momentum D. none of the above

A. mass

Bernoulli’s equation deals with the law of conservation of _____ A. mass B. momentum C. energy D. work

C. energy

all the terms of energy in Bernoulli’s equation have dimension of _____ A. energy B. work C. mass D. length

D. length

the losses of energy in pipes due to _____ A. friction of surface B. sudden enlargement or contraction of area C. any obstruction in the path of flow D. all of these

D. all of these

the major loss of energy in long pipes is due to _____ A. sudden enlargement B. sudden contraction C. gradual contraction or enlargement D. friction

D. friction

which one of the following is a major loss? A. frictional loss B. shock loss C. entry loss D. exit loss

A. frictional loss

minor losses occur due to _____ A. sudden enlargement in the pipe B. sudden contraction in the pipe C. bends in pipe D. all of the above

D. all of the above

minor losses do not make any serious effect in _____ A. short pipes B. long pipes C. both the short as well as long pipes D. cannot say

B. long pipes

in series – pipe problems A. the head loss is same through each pipe B. the discharge is same through each pipe C. a trial solution is not necessary D. the discharge through each pipe is added to obtain total discharge

B. the discharge is same through each pipe

which of the following conditions is valid in the case of flow through parallel pipes? A. the rate of discharge in the main line is not equal to the sum of the discharges in each of the parallel pipes B. the velocity of flow in the main line is equal to the sum of the velocities in each of the parallel pipes C. the loss of head in each parallel pipe is different D. the rate of discharge in the main line is equal to the sum of discharges in each of the parallel pipes

D. the rate of discharge in the main line is equal to the sum of discharges in each of the parallel pipes

two pipe systems are said to be equivalent when _____ A. head loss and discharge are same in two systems B. length of pipe and discharge are same in two systems C. friction factor and length are same in two systems D. length and diameter are same in two systems

A. head loss and discharge are same in two systems

the ratio of absolute viscosity to mass density is known as _____ A. specific viscosity B. viscosity index C. kinematic viscosity D. coefficient of viscosity

C. kinematic viscosity

the magnitude of water hammer effect in a pipe depends on _____ A. speed at which the valve is closed B. length of the pipe C. elastic properties of the pipe material D. all of the above

D. all of the above

the phenomenon of water hammer takes place in pipes _____ A. when water is suddenly accelerated by opening the valve B. when fluid is moving with high head C. when pressure is reduced to zero D. when fluid is suddenly brought to rest by closing the valve

D. when fluid is suddenly brought to rest by closing the valve

water hammer pressure can be considerably reduced using _____ A. slow closing valves B. rapid closing valves C. both slow and rapid closing valves D. none of the avalves (hahahaha havey)

A. slow closing valves

the ratio of inertia force and gravitational force is called as _____ A. Reynolds number B. Stokes number C. Froude’s number D. Euler’s number

C. Froude’s number

which geometric parameter determines the efficiency of the channel? A. hydraulic depth B. hydraulic radius C. section factor D. normal depth

B. hydraulic radius

for a channel to be economic which of the following parameters should be minimum? A. wetted perimeter B. wetted area C. section factor D. hydraulic depth

A. wetted perimeter

what is the depth of flow in case most economical circular section considering maximum velocity? A. 0.61D B. 0.71D C. 0.81D D. 0.91D

C. 0.81D

differential manometer is used to measure _____ A. pressure in pipes, channels etc. B. atmospheric pressure C. very low pressure D. difference of pressure between two points

D. difference of pressure between two points

non-uniform flow occurs when _____ A. the direction and magnitude of the velocity at all points are identical B. the velocity of successive fluid particles, at any point, is the same at successive periods of time C. velocity, depth, pressure, etc. change from point to point in the fluid flow D. the fluid particles move in plane or parallel planes and the streamline patterns are identical in each plane

C. velocity, depth, pressure, etc. change from point to point in the fluid flow

when a tube of smaller diameter is dipped in water, the water rises in the tube with an upward _____ surface A. concave B. convex C. plane D. none of these

A. concave

the tendency of a liquid surface to contract is due to the following property A. cohesion B. adhesion C. viscosity D. surface tension

D. surface tension

the pressure measured with the help of a pressure gauge is called _____ A. atmospheric pressure B. gauge pressure C. absolute pressure D. mean pressure

B. gauge pressure

capillary action is due to the _____ A. surface tension B. cohesion of the liquid C. adhesion of the liquid molecules and the molecules on the surface of a solid D. all of the above

D. all of the above

the intensity of pressure on an immersed surface _____ with the increase in depth A. does not change B. increases C. decreases D. none of these

B. increases

free surface of a liquid behaves like a sheet and tends to contract to smallest possible area due to the _____ A. force of adhesion B. force of cohesion C. force of friction D. force of diffusion

B. force of cohesion

the hydraulic gradient line lies over the centre line of the pipe by an amount equal to the _____ A. pressure head B. velocity head C. pressure head + velocity head D. pressure head - velocity head

A. pressure head