Terms Flashcards
It is defined as the mass per unit volume of a substance:
mass density
“At any point in a fluid at rest the pressure is the same in
all directions” this Law is known as:
Pascal’s Law
The pressure measured by means or gages above or
below the atmospheric level is called:
absolute pressure
The pressure measure above the absolute zero is called:
vapor pressure
A pressure measuring technique by means of tubes
usually shaped in the form of U’s and utilizing the principles
of hydrostatic is known as:
barometry
A type of manometer which is used for measuring gage
pressure with the use of gage liquid. This type contains an
atmospheric level.
open type
A manometer used for measuring the difference in
pressure between two points and does not have an
atmospheric level.
differential manometer
The centroid of the submerged coincides with the center
of pressure if:
the surface is horizontal
When the center of gravity of a floating body is farther
than the metacenter when referred to the center of
buoyancy (considering that the center of gravity is above the
center of buoyancy), the floating body is in:
unstable equilibrium
The horizontal component of the hydrostatic force
acting on the curved surface is equal to
Hyrdrostatic force acting of the vertical projection of the
curved surface.
The most efficient section for an open channel is:
semi-circular section
“Anybody submerged in a fluid is acted upon by and
unbalanced force (buoyant force) which is equal to the
weight of the displaced fluid”. This principle is known as:
Archimedes Principle
The metacentric height of a floating body is the distance
from the metacenter to the:
center of gravity
In a system of pipes in parallel, the:
head losses are equal
The buoyant force, BF, which is equal to the weight of
the displaced fluid is acting at the:
centroid of the displaced volume of fluid
A floating body is said to be stable when the metacenter
is:
above the center of gravity
The use of Angat Dam (in Bulacan) is multi-purpose in
nature and in case of extreme energy during periods of long
drought, the priority use of water will be:
water supply use
Deep groundwater deposits where underground water
are available for water supply and irrigation is known as:
aquifers
The distribution of discharge from all runoff sources
plotted as a function of time results to a graph which is
known as:
mass curve
In a horizontal uniform circular pipe, the head loss
between any two flow section is a direct measure of.
the difference in pressure heads & difference in the
elevation heads
In a system of pipes in series, the:
flows are equal
In fluid flow, if the fluid travels parallel to the adjacent
layers and the paths of individual particles do not cross; the
flow is said to be:
laminar
The headloss in a nozzle usually expressed in terms of:
the coefficient of velocity and velocity head
The locus of the elevation to which water will rise in a
piezometer tube is termed as:
the hydraulic gradient
The result of static pressure in the fluid becoming less than fluid vapor
pressure
Cavitation
A condition of flow characterized when fluid particles
move in very irregular paths, causing an exchange of
momentum from one portion of the fluid to another is:
turbulent flow
The difference between the hydraulic grade line and
energy grade line is:
velocity head
It is an overflow structure built across an open channel
for the purpose of measuring or controlling the flow.
weir
“The theoretical velocity of a jet of liquid issuing out of
an orifice under a head of h being equal to the velocity of a
free falling body dropping through a height of h” is known as
the:
Torricelli Law
In a Pitot tube, the point of stagnation is the point
where:
the velocity is zero
In the Venturi Meter, the section with the smallest
pressure is:
throat
The vena contracta of sharp-edged hydraulic orifice
usually occurs:
at a distance of 0.5D downstream from the plane of the
orifice
A type of open channel flow where the Froude Number
is equal to 1:
critical flow
A jump is possible to occur in an open channel when the
flow is super critical, that is when the Froude Number is:
greater than 1
The length of the apron of a dam’s spillway can be
minimized by necessitating the jump to be localized through
the absorption of the excess energy in the flow and
construction of:
energy dissipaters
In the construction of sewer pipes, attempts should be
made to follow the slope of the ground surface with the
slope of the sewer. This will tend to:
minimize required excavation depth
The science of Hydrology encompasses the behavior of
water as it occurs in the atmosphere, on the surface of the
ground and underground or the movement of water as it
relates to the earth is known as:
hydrologic cycle
For large basins ranging from 2000 to 10000 sq. miles
representing the storm area where geographical variation in
rainfall. depth patterns complex config., can be well defined
in determining the ave. precipitation over an area by the
method which is known as:
isoyetal map method
A branch of science that deals with the study of water in
all its form and from all its origin to all its destination on the
earth.
hydrology
In the design of waterways, the “hydraulic jump” is
sometimes used for:
energy dissipation
One of the rational methods determining the reservoir-
capacity yield analysis in dam design is known as:
mass curve
Must always occur above critical depth
Subcritical flow
A branch of science that deals with the study of water in
all its form and from all its origin to all its destination on the
earth.
hydrology
The slope of the channel is considered mild
super critical flow
In water purification, aeration is used to remove:
objectionable gases
Entrance losses between tank and pipe, or losses
through elbows, fittings and valves are generally expressed
as a function of:
kinetic energy
In fluid flow, the liquid travels parallel to the adjacent
layers, and the paths on individual particles does not cross
or intersect, the flow is said to be:
uniform
When the amount and velocity of fluid passing at any
section at a given length or reach is constant with time, the
flow is said to be:
uniform
In fluid flow, when the amount of fluid passing at a
section is constant with time, the flow is said to be:
steady
Frictionless and incompressible
Ideal flow
Equal to the weight of displaced fluid
Bouyant force
In ____, the fluid particles move in an orderly manner
laminar flow
A body floats is said to be just stable.
when its metacentric height is zero
Measures the velocity at the stagnation point:
simple pitot tube
Measures static pressure
pitot-static
The hot- wire anemometer is used to measure
gas velocities
The centroid of the pressure prism
pressure center
A force component parallel to the relative approach
velocity exerted on the body by the moving fluids, called:
viscosity
A short pipe whose length is not more than two or three
diameters.
tube
The total hydrostatic pressure on a plane area is located
1/3 of the height of the liquid from the bottom if:
a) the width is uniform
b) the liquid surface is level with the top of the body
c) the liquid surface is atmospheric
d) none of the above
d) none of the above
Hydraulic jump is possible to occur in rectangular
channel it:
a) the depth is critical
b) the Froude number is less than one
c) the Froude number is equal to one
d) none of the above
d) none of the above
Each number is a dimensionless ratio of the velocity of
the fluid to the acoustic velocity, called as:
celerity
A motion caused by rotating impellers or by rotating a
vessel containing a liquid is called:
forced vortex
The ratio of the area of a jet at the vena contracta to the
area of the orifice or other opening is called as:
coefficient of contraction
In the design of waterways, the “hydraulic jump” is
sometimes used for:
energy dissipation
The velocity of a fluid approaching an orifice or nozzle or
similar device is called:
velocity of approach
In fluid flow, if the fluid travels parallel to the adjacent
layers and the paths of individual particles do not cross; the
flow is said to be:
laminar
If the velocity of a liquid in a pipeline is abruptly
decreased by a valve moment, the phenomenon
encountered is called:
water hammer
The branch of science that deals with the study of water
in all of its form and from its origin to all its destination on
the earth is known as:
hydrology
The most efficient condition for open channel flow in
circular pipes is when:
it is flowing at a depth = 94% of the diameter
A cylinder of cork is floating upright in a tank partially
filled with water. A vacuum is applied to the such that the
air within it is partially removed. The cork will:
remain stationery
This phenomenon occurs in a flow at a point along the
boundaries where the streamlines are spreading and the
velocity gradient zero:
separation
The center of a circle traced by the centroid of the
submerged portion of a floating body is known as:
metacenter
The pressure exerted by the atmosphere in every
surface with which it comes in contact is known as:
atmospheric pressure
Fluids which have little resistance to change either in
form or volume. It occupies all the space in which it is
contained.
gases
When the gage liquid of an open manometer, is
deflected towards the point of connection it implies that the
gage pressure at the point of connection is:
negative
Absolute viscosity of a fluid varies with pressure and
temperature and is defined as a function of:
shear stress and angular deformation rate
The capillary rise (or depression), h, in a circular tube
with radius r is directly proportional to the surface tension
of the liquid contained in the tube. The relationship
between h and r is:
h is inversely proportional to r
Absolute viscosity of a fluid varies with pressure and
temperature and is defined as a function of:
density, shear stress and angular deformation rate
Fluids which offer great resistance to change in volume.
It occupies a definite portion in which it is contained.
liquids
It is defined as the weight of a unit volume of a
substance.
specific weight
The quantitative measure of the amount of matter in a
given body is known as:
Mass
It is a dimensionless ratio of the density (or specific
weight) of a substance to that of some other standard
substance.
specific gravity
All the following is true about absolute pressure, except:
absolute pressure can be negative
A mass of liquid being translated vertically downward
with a uniform acceleration equal to the acceleration of
gravity has, at any point in the mass, a pressure:
equal to zero
The hydrostatic pressure force which varies uniformly
from the heel to the toe of the base width of the dam for
design consideration. Is known. as:
uplift pressure force
A principal in flow measurement which states that the
increase in kinetic energy per unit weight is equal to the decrease in the potential energy per unit weight, is known as:
Ventur Principle
Two jets of water, having the same velocity, one issuing
horizontally and the other vertically at the same elevation,
will strike the horizontal ground below with:
an increased equal kinetic energies
A Sutro-weir or “proportional-flow weir where the
discharge is:
directly proportional to the first power of the head
Total energy of compressible incompressible fluid
flowing across any section in a pipeline is a function of:
flow energy, kinetic energy, height above datum and
internal energy
It defined as a conduit in which the liquid flows with free
surface subiected to atmospheric, pressure. The flow is
caused by the slope of the conduit and the liquid surface.
open channel flow
In open channel flow, many problems are solved by the
special application of the energy principle which is defined
as the distance between channel bottom and the energy
line. This distance is known as.
specific energy
Uniform flow in an open channel implies the following
characteristics, except:
datum parallel to surface
For optimum flow conditions to occur in a V-notch open
channel.
the depth of flow must twice the width of surface
The two alternate depths of flow in open channel (the
subcritical and super critical) are two possible depths that,
for a constant specific energy, the:
unit discharge is the same
The fundamental objective of the hydraulic design of
culverts for which the design discharge is passed without
exceeding the allowable headwater elevation is:
to determine most economic diameters
The residual of precipitation that is drained from the
land after the prior and persistent demands of
evapotranspiration have been met is known as:
surface runoff
The hydraulic radius of an open-channel section is
defined as:
the cross-sectional area divided by the wetted perimeter
In an open channel flow, the hydraulic grade line is the:
water surface
The sudden removal of land from the state of one man.
to that of another, as by a sudden change in a river, the
property thus separated continuing in the original owner of
the sudden shift in location of a channel is known as:
avulsion
Which of the following statements nearly approximates
conditions in turbulent most flow?
energy loss varies as the square of the velocity
At critical velocities in small pipes or at very low velocities, the loss of head due to friction
varies directly as the velocity
The normal stress is the same in all directions at a point
in a fluid
only when there is no motion of one fluid layer relative to
adjacent layer
The horizontal component of force on a curved surface
is equal to the:
product of pressure at its centroid and area of the vertical
projection
The vertical component of pressure force on a
submerged curve surface is equal to:
gravity force of liquid vertically above the curved surface
The line of action of the buoyant force acts through the:
centroid of the displaced volume of fluid
When a liquid rotates at constant angular velocity about
a vertical axis as a rigid body the pressure
Varies as the square of the radial distance
Occurs when the fluid rotates as a solid
forced vortex
The losses in open-channel flow generally varies as the:
square of the velocity
Occurs when conditions are the same at adjacent points at any instant
Steady flow
Is larger when the fluid is more compressible
bulk modulus of elasticity
The normal stress is the same in all directions at a point
in a fluid:
when there is no motion of one fluid layer relative to an
adjacent layer
The velocity of a known flowing gas may be determined
from measurement of:
static pressure and temperature only
The losses in open-channel flow generally vary as the:
square of the velocity
Drawn normal to the velocity vector at every point
streamline
Pressure drag results from:
skin friction
