Terms I

Question 1

An instrument to measure the density of oils.

Answer 1

Acrometer

Question 2

A semi liquid mass removed from the liquid flow of sewage
and subjected to aeration and aerobic microbial action: the
end product is dark to golden brown, partially decomposed,
granular and flocculent and has an earth odor when fresh.

Answer 2

Activated sludge

Question 3

A fluid property which refers to the attractive force between
its molecules and any solid substance with which they are in
contact.

Answer 3

Adhesion

Question 4

Soil formed from wind transported soil material.

Answer 4

Aeolian Soil

Question 5

A concrete, steel or fiberglass tank in which sewage effluent
is brought into contact with dissolved oxygen and flocs in
the activated-sludge process.

Answer 5

Aeration tank

Question 6

A self-recording instrument used on aircraft for the
simultaneous recording of atmospheric pressure,
temperature and humidity.

Answer 6

Aerometeorograph

Question 7

An instrument to ascertain the weight or density of air or
other gases.

Answer 7

Aerometer

Question 8

A device for measuring the proportion of the total volume of the soil which is occupied by air.

Answer 8

Air Picnometer

Question 9

A barometer with no liquid: _ is used
for measuring the pressure of the atmosphere.

Answer 9

Aneroid barometer

Question 10

A device used for measuring atmospheric pressure.

Answer 10

Barometer

Question 11

Also known as Bend meter or Bendometer. A calibrated
bend or elbow with suitable upstream and downstream
straight lengths for measurement of flows.

Answer 11

Bentometer

Question 12

An instrument designed by Bentzel for measuring velocity of
fluids.

Answer 12

Bentzel tube

Question 13

Neglecting friction, the total head, of the total amount of
energy per unit of weight is the same at every point in the
path of flow.

Answer 13

Bernoulli’s energy theorem

Question 14

A re-entrant tube consisting of a thin tube projecting into
the reservoir about one diameter which uses the principle of
pressure momentum theory which states that force equals
the rate of change of momentum.

Answer 14

Bordas mouth piece

Question 15

The ratio of the change in unit pressure to the
corresponding volume change per unit volume.

Answer 15

Bulk modulus of elasticity

Question 16

A contracted sharp-crested measuring weir, in which each
side of the notch has a slope of 1 horizontal to 4 vertical, to
compensate for end contractions; named after Cesare
Cipolletti, an Italian engineer.

Answer 16

Cipolletti (weir also known as Trapezoidal weir)

Question 17

The ratio of the cross sectional area of the jet at the vena
contracta to the area of the orifice.

Answer 17

Coefficient of contraction

Question 18

The product of the coefficient velocity by the coefficient of
contraction.

Answer 18

Coefficient of discharge

Question 19

Term for impermeability factor.

Answer 19

Coefficient of imperviousness

Question 20

The tangent of the angle o, the angle of internal friction.

Answer 20

Coefficient of internal friction

Question 21

The ratio of absolute viscosity to the mass density.

Answer 21

Coefficient of Kinematic viscosity

Question 22

The imaginary average velocity of flow through the total
(voids and solids) area of soil under a hydraulic gradient of 1.

Answer 22

Coefficient of permeability

Question 23

The ratio of the actual mean velocity of jet to the velocity
which would exist without friction.

Answer 23

Coefficient of velocity

Question 24

The ratio between the grain diameter which is larger than
60% by weight of the particles in a soil sample, to that
diameter the effective size, which is larger than 10% by
weight of the particles. It is more briefly expressed as
D6o/D10.

Answer 24

Coefficient of uniformity, modulus of uniformity

Question 25

A fluid property which refers to the intermolecular attraction by which the separate particles of the fluid are held together.

Answer 25

Cohesion

Question 26

Rate of discharge of water through a porous medium per unit of total area perpendicular to the direction of flow.

Answer 26

Discharge velocity

Question 27

Also known as Secondary canals which take off from the main canals or branches and supply water to minors and outlets or turnouts.

Answer 27

Distributaries

Question 28

A fixed dam for diverting stream water away from its course.

Answer 28

Diversion dam

Question 29

A shear test or triaxial compression test applied to a specimen of cohesive soil after completed consolidation under normal load, carried out in drained conditions slowly enough to allow further consolidation due to shear during the test.

Answer 29

Drained shear test, slow test

Question 30

Lowering of a water level.

Answer 30

Drawdown

Question 31

The ratio of the tail water elevation to the head water elevation, when both are higher than the crest, the overflow crest of the structure being the datum of reference.

Answer 31

Drawing ratio

Question 32

The weight of dry material in unit volume a soil sample after drying at 105°C.

Answer 32

Dry density

Question 33

The property of a fluid which determines the amount of its resistance to a shearing stress.

Answer 33

Dynamic viscosity

Question 34

The pressure or force exerted by soil on any boundary.

Answer 34

Earth pressure

Question 35

A branch of science which deals with the study of water and other fluids that are at rest or in motion.

Answer 35

Fluid mechanics

Question 36

The study of fluid problems in which there is no relative motion between fluid elements and thus no velocity gradients and no shear stress to exist.

Answer 36

Fluid statics

Question 37

An open channel constructed of steel, reinforced concrete or wood and used to convey water to be utilized for power, to transport logs, and so on.

Answer 37

Flume

Question 38

A reservoir at the end of a pipeline, particularly above hydroelectric power station.

Answer 38

Forebay

Question 39

In an open channel, a ratio which should be the same for the model analysis as in the full size project. It is the velocity squared divided by depth times the acceleration of gravity.

Answer 39

Froude number

Question 40

A law, complementary to Charles' Law defining the behavior of a perfect gas at constant volume. The law states that if the volume of a given mass of a perfect gas be kept constant, then its absolute pressure will vary in direct proportion to temperature.

Answer 40

Gay Lussac's law

Question 41

The design and manufacturing of pumping plant, reservoir valves, penstocks, pipelines and so on.

Answer 41

Hydraulic engineering

Question 42

A phenomenon where the flow is super critical in an upstream section of channel and is then forced to become sub critical in a downstream section (the change in depth can be forced by a sill in the downstream part of the channel or just be the prevailing depth in the stream further downstream) a rather abrupt change in depth usually occurs.

Answer 42

Hydraulic jump

Question 43

The branch of mechanics which deals with the laws governing the behavior of water and other liquids in the states of rest and motion.

Answer 43

Hydraulics

Question 44

A branch of hydraulics which deals with the study of forces (including velocity, and acceleration) exerted by or upon liquids in motion.

Answer 44

Hydrodynamics

Question 45

Deals with liquids that are in motion with respect to both to the earth and to their containers.

Answer 45

Hydrokinetics

Question 46

Pressure caused by a head of water.

Answer 46

Hydrostatic pressure

Question 47

A branch of hydraulics which deals on the study of fluids at rest.

Answer 47

Hydrostatics

Question 48

A sewer connecting individual drains which formerly went direct to a river or the sea. It takes their flows to the sewage treatment plant.

Answer 48

Interceptor

Question 49

The ability of a mass to do work by virtue of its velocity.

Answer 49

Kinetic energy

Question 50

The three forms of energy which must be considered in connection with flow of liquids.

Answer 50

Kinetic energy, Elevation energy, Pressure energy

Question 51

Type of flow when the paths of individual particles do not cross or intersect.

Answer 51

Laminar

Question 52

A device for measuring fluid pressure which consists of a bent tube containing one or more liquids of different specific gravity.

Answer 52

Manometer

Question 53

The ratio of mass per unit volume.

Answer 53

Mass density of a body

Question 54

Fluids which undergo a proportionality of shear stress to the rate of shear strain holds.

Answer 54

Newtonian Fluids

Question 55

Fluid for which the shear stress is directly proportional to the rate of strain.

Answer 55

Newtonian fluids

Question 56

A converging tube attached to the end of a pipe or hose which serves to increase the velocity of the issuing jet.

Answer 56

Nozzle

Question 57

A conduit in which a liquid flows with a free surface.

Answer 57

Open channel

Question 58

An opening with a closed perimeter through which a fluid flows.

Answer 58

Orifice

Question 59

The pressure intensity at a point is of equal magnitude in all direction, this principle.

Answer 59

Pascal's Law

Question 60

A device for measuring fluid pressure by determining the height to which liquid rises.

Answer 60

Piezometer

Question 61

A closed conduit through which liquid or gases flow

Answer 61

Pipe

Question 62

Any body immersed in fluid is subjected to a buoyant for equal to the weight of displaced liquid.

Answer 62

Principle of Archimedes

Question 63

It the ratio of inertial forces to viscous forces.

Answer 63

Reynolds No.

Question 64

Ratio of weight of substance to the weight of equal volume of water.

Answer 64

Specific gravity

Question 65

The point which flow occurs around a body, part of it will go to one side and part to the other side. The stream line that follows the flow division (that divides on the upstream side of the body and join again on the down stream side is called dividing streamline). Also at the point of division the velocity will be zero.

Answer 65

Stagnation point

Question 66

A tube with square-cornered entrance and a length about 1/2 times its diameter.

Answer 66

Standard short tube

Question 67

The force per unit length that an "imaginary film" formed on the surface of a liquid due to the intermolecular attraction is capable of exerting.

Answer 67

Surface Tension

Question 68

The speed of efflux is equal to the speed of force fall from the surface of reservoir.

Answer 68

Torricelli Theorem

Question 69

A space that has a pressure less than atmospheric pressure.

Answer 69

Vacuum

Question 70

The pressure at which a liquid will boil.

Answer 70

Vapor pressure

Question 71

An instrument which is used for measuring the discharge through pipes which consists of a short converging tube connected to the approach pipe at the inlet and ending in a cylindrical section called the throat.

Answer 71

Venturi meter

Question 72

The property of a fluid which determines the amount of its resistance to shearing force.

Answer 72

Viscosity

Question 73

An over flow structure built across an open channel for the purpose measuring the flow.

Answer 73

Weir