A circular sewer section is preferred to because
1. it provides maximum hydraulic mea depth
2.it provides maximum area for a given perimeter
3.it is cheaper in construction
4.All of the above
A commonly used handpump is
1.axial flow pump
2.centrifugal pump
3.rotary pump
4.reciprocating pump
A garden developed over top of surface water tank is known as
1.water tank garden
2.hanging garden
3.municipal garden
4.none of these
A pipe sunk into the well to tap underground water is called
1.artesian well
2.open well
3. infiltration well
4. tube well
A timber dam is a
1.detention dam
2.rigid dam
3. non-rigid dam
4.non-overflow dam
Aerosol is
1.diffused liquid particles
2.carbon particles of microscopic size
3.dispersion of small solid or liquid particles in gaseous media
4.finely divided particles of ash
All major and important gravity dams are nowadays constructed with
1.concrete
2.earth and rock fill
3. brick masonry
4.stone masonry
Bacteria that need oxygen to live are known as
1. pathogenic bacteria
2.facultative bacteria
3.anaerobic bacteria
4.aerobic bacteria
Bacteria that survive in the absence of oxygen are known as (B) aerobic bacteria (C) facultative bacteria (D)
1.anaerobic bacteria
2.aerobic bacteria
3.facultative bacteria
4.pathogenic bacteria
Bacteria that survive in the absence of oxygen are known as
1.anaerobic bacteria
2.aerobic bacteria
3.facultative bacteria
4.pathogenic bacteria
Coli or E. Coli are harmless organisms but their presence in water indicates the
1. Absence of pathogenic bacteria
2.Absence of non pathogenic bacteria
3.Presence of non pathogenic bacteria
4.Presence of pathogenic bacteria
Colorimetric method of testing water is to determine
1. turbidity
2.hardness
3.chlorides
4.pH value
Cowl is provided at
1. first step in manhole
2.upper end of the manhole
3. lower end of ventilating column
4.upper end of ventilating column
Depletion of ozone layer in the outer atmosphere may causes
1.heart disorder
2.bronchitis
3.skin cancer
4.lung cancer
detention dam
1.algae
2.rigid dam
3.non-rigid dam
4.non-overflow dam
Floatation is a method of water purification by
1.Ion transfer
2.Gas transfer
3.Solid transfer
4.Solute stabilization
For an area developed in haphazard way, the type of layout of water distribution system preferred as
1. radial system
2. ring system
3.grid iron system
4. dead end system
For trunk and out fall, the type of sewers generally used is
1. circular shaped
2.horse shoe shaped
3.parabolic shaped
4.standard egg shaped
Ground water is usually free from
1.dissolved impurities
2.suspended impurities
3. both suspended and dissolved impurities
4.none of the above
In a dam project geological investigations are to get information about
1. Structural features of rock such as folds, faults, fissures
2.Type and depth of overburden
3.Water tightness of the reservoir basin
4. All the above
In a rapid sand filter
1.Water from sedimentation tank is supplied
2.Water from coagulation tank is supplied
3.Raw water from the source is supplied
4. Any one of the above
In sewers the effect of scouring is more on
1.horizontal side
2.top side
3.bottom side
4.all sides
In treatment swimming pool water the filtration system to be used is
1.slow sand filters
2.pressure filters
3.rapid sand filters
4. All of the above
Meyer's and Rohwer's formula are used to determine.
1.evaporation
2.average rainfall over a basin
3.transpiration
4.precipitation
Permanent hardness of water can be removed by
1.adding alum
2.adding chlorine
3.boiling
4. lime soda process
pH value of water indicates
1.acidity of alkalinity
2.turbidity
3.turbidity
4.turbidity
Process of killing pathogenic bacteria from water is known as
1.sedimentation
2.disinfection
3.coagulation
4.filtration
Rainwater of the locality which flows in sewer is called
1.subsoil water
2. storm water
3.combined sewage
4.sullage
Sphere shaped bacteria are called
1.trichobacteria
2.cocci
3.bacilli
4.spirilla
Stone ware pipes are
1. specially suited to pressure pipes
2.hydraulically efficient because of their smooth interior surface
3.highly impervious
4.highly resistant to sulphide corrosion
Suspended impurities in water is
1.algae
2.bacteria
3.silts
4.all of these
Temporary hardness in water is caused by the presence of
1.chlorides of Ca and Mg
2.bicarbonate of Ca and Mg
3.sulphates of Ca and Mg
4.nitrates of Ca and Mg
Temporary hardness of water may be removed by
1.De-ionization method
2.Zeoloite process
3.Lime soda process
4.Boiling
The chemical most commonly used to increase speed of sedimentation of sewage is
1.lime
2.sodium permanganate
3.sodium permanganate
4.sodium permanganate
The controlling design parameter in the design of all setting tanks is
1.depth
2.percent removal of suspended solids
3.overflow rate
4.detention time
The flowing river water in natural drainage gets cleaned by
1.photosynthesis
2. self purification
3.oxidation
4.none of these
The layer on the top of a filtering medium formed by organic impurities is known as
1.dirty skin
2.tube settler
3.permeable layer
4.filtering layer
The most common and universal coagulant used in water works is
1. magnesium sulphate
2.calcium sulphate
3.chlorine
4.aluminium sulphate
The sewer which obtains its discharge from two or more sewers is known as
1.common sewer
2.common sewer
3.trunk sewer
4.depressed sewer
The suitable method for disinfection of swimming pool water is
1.chlorination
2. by using potassium permanganate
3.ultra violet rays treatment
4. lime treatment
The suitable method of forecasting population for a young and rapidly increasing city is
1.graphical method
2. incremental increase method
3.geometrical increase method
4. arithmetical increase method
Turbidity is measured on
1. platinum cobalt scale
2.standard platinum scale
3.standard cobalt scale
4. standard silica scale
Water obtained from _____ is generally known as sub surface water.
1.Artesian wells
2.Reservoirs
3.Rivers
4.Rains
Water with maximum alkalinity pH value is
1.4
2.7
3.14
4.18
Which one of the following causes cumulative poisoning by water?
1. lead
2.iron
3.barium
4.manganese
Which one of the following is not a coagulating agent?
1. Aluminium sulphate
2.Copper sulphate
3.Chlorinated coppers
4.Sodium aluminate
Which one of the following is not a dissolved impurity of water
1. Iron oxide
2.Bacteria
3.Carbon dioxide
4.Calcium carbonate
Which one of the following is not a type of tube well?
1.Strainer well
2.Slotted well
3.Cavity well
4.Gravity welll
Which one of the following is not ground water?
1.from river side radial collector wells
2.from infiltration gallaries
3.water from natural springs
4.rooftop water stored in underground tank
Which one of the following is not turbidity test on water?
1.Hehner's method
2.Nephelometer
3. Baylis
4.Jackson's
Which one of the following would contain water with the maximum amount of turbidity?
1.wells
2.rivers
3.oceans
4.lakes
Winter rainfall in Tamil Nadu is mainly due to
1.orographic precipitation
2. precipitation due to turbulent ascent
3.cyclonic precipitation
4.convective precipitation
With self cleansing velocity in sewers
1.With self cleansing velocity in sewers
2.neither silting nor scouring occurs at bottom
3.both silting and scouring occur at bottom
4.scouring occurs at bottom
Zero hardness of water is achieved by
1.using excess alum dosage
2.ion exchange method
3.excess lime treatment
4.using lime soda process