1) Absolutely soft waters are required for
a) prevention of corrosion in pipes
b) drinking
c) washing with synthetic detergent soap
d) boilers
2) Hardness is desirable for
a) cardiovascular diseases
b) laundering
c) wash water of sinks and porcelain tubs
d) boiler feed water
3) A desirable feature of hardness is
a) vegetables toughened
b) more soap consumed
c) scales formed inside pipes protect them from corrosion
d) skin roughened
4) A factor affecting domestic demand is
a) dead end system or reticulation system of network of pipes
b) timing of water supply
c) water supplied is soft or hard
d) climatic conditions
5) For an old city with constraints for growth the best method of forecasting future population is
a) incremental increase method
b) geometrical increase method
c) arithmetical increase method
d) graphical method
6) Design period mainly depends on
a) rate of growth of population
b) capacity of the municipality to repay
c) quality of fittings used
d) percentage interest at which the loan is taken
7) A good source of water requiring practically the least treatment is
a) a deep well
b) an impounded reservoir
c) an elevated lake
d) a perennial river
8) The distribution mains are designed for
a) maximum daily demand
b) average daily demand
c) maximum hourly demand
d) maximum hourly demand on maximum day
9) As compared to geometrical increase method of forecasting population, arithmetical increase method gives
a) lesser value
b) same value
c) accurate value
d) higher value
10) The suitable method of forecasting population for a young and rapidly increasing city is
a) graphical method
b) geometrical increase method
c) arithmetical increase method
d) incremental increase method
11) Ground water is usually free from
a) suspended impurities
b) dissolved impurities
c) both suspended and dissolved impurities
d) none of the above
12) Turbidity is measured on
a) standard platinum scale
b) standard silica scale
c) standard cobalt scale
d) platinum cobalt scale
13) Residual chlorine in water is determined by
a) starch iodide method
b) orthotolidine method
c) both (a) and (b)
d) none of the above
14) Orthotolidine test is used for determination of
a) residual chlorine
b) dose of coagulant
c) biochemical oxygen demand
d) dissolved oxygen
15) Disinfection of water results in
a) removal of turbidity
b) removal of hardness
c) killing of disease bacteria
d) complete sterilisation
16) Chlorine demand of water is equal to
a) difference of applied and residual chlorine
b) applied chlorine
c) residual chlorine
d) sum of applied and residual chlorine
17) The process in which the chlorination is done beyond the break point is known as
a) super chlorination
b) post chlorination
c) break point chlorination
d) pre- chlorination
18) Treatment of water powder is known as
a) hypo- chlorination
b) de- chlorination
c) pre- chlorination
d) super chlorination
19) In chlorination, with the rise in temperature of water, death rate of bacteria
a) increases
b) decreases
c) remains unaffected
d) none of the above
20) The layout of distribution system in which water flows towards the outer periphery is
a) grid iron system
b) dead end system
c) radial system
d) ring system
21) The suitable layout of distribution system for a city with roads of rectangular pattern
a) radial system
b) dead end system
c) ring system
d) grid iron system
22) The suitable system of sanitation for area of distributed rainfall throughout the year with less intensity is
a) partially separate system
b) combined system
c) partially combined system
d) separate system
23) The water carriage system of collection of waste product
a) is cheaper in initial cost than dry conservancy system
b) requires treatment before disposal
c) creates hygenic problem
d) all of the above
24) slope of sewer shall be
a) given in the direction of natural slope of ground
b) given in the direction opposite to natural slope of ground
c) zero
d) steeper than 1 in 20
25) The velocity of flow does not depend on
a) grade of sewer
b) length of sewer
c) hydraulic mean depth of sewer
d) roughness of sewer
26) The main disadvantage of cement concrete sewers is
a) less strength
b) difficulty in transportation due to heavy weight
c) less life
d) difficulty in construction
27) Most suitable section of sewer in separate sewage system is
a) standard form of egg shaped sewer
b) rectangular section
c) circular section
d) modified egg shaped section
28) An egg shaped section of sewer
a) provides self cleansing velocity at low discharges
b) is more stable than circular section
c) is easy to construct
d) is economical than circular section
29) The type of sewer which is suitable for both combined and separate system is
a) circular sewer
b) horse- shoe type sewer
c) semi- elliptical sewer
d) egg shaped sewer
30) Dissolved oxygen in streams is
a) maximum at noon
b) maximum at midnight
c) mimimum at noon
d) same throughout the day
31) Sewerage system is designed for
a) minimum flow only
b) maximum and minimum flow
c) maximum flow only
d) average flow only
32) Facultative bacteria are able to work in
a) presence of water
b) absence of oxygen only
c) presence as well as in absence of oxygen
d) presence of oxygen only
33) Sewage treatment units are designed for
a) minimum flow only
b) average flow only
c) maximum flow only
d) maximum and minimum flow
34) The pipe which is used to carry the discharge from sanitary fittings like bathrooms, kitchens etc. is called
a) antisiphonage pipe
b) waste pipe
c) vent pipe
d) soil pipe
35) Most of the bacteria in sewage are
a) pathogenic
b) parasitic
c) saprophytic
d) anaerobic
36) The biochemical treatment of sewage effluents is essentially a process of
a) dehydration
b) reduction
c) alkalinization
d) oxidation
37) Shrouding is provided in
a) slotted pipe tubewell
b) cavity type tubewell
c) strainer type tubewell
d) none of above
38) Select the primary air pollutants among the following:
a) nitrogen oxide and ozone
b) ozone and carbon monoxide
c) sulphur dioxide and nitrogen oxides
d) sulphur dioxide and ozone
39) The depletion of ozone in the outer atmosphere may result in increased
a) heart attack cases
b) skin cancer cases
c) asthma cases
d) none of the above
40) Blue baby disease (methemoglobinemia) in children is caused by the presence of
a) fluorides
b) nitrates
c) lead
d) chlorides
41) De-chlorination of water is achieved by adding
a) sodium thiosulphate
b) sodium sulphate
c) sodium hexametaphosphate
d) sodium bisulphate
42) If present in water, chlorination of water does not reduce the
a) dissolved oxygen content
b) organic matter content
c) B.O.D.
d) ammonia content
43) The efficiency of a sedimentation tank does not depend upon
a) length of the tank
b) detention time
c) depth of the tank
d) horizontal velocity of water
44) Sewage sickness relates to
a) reduction in the waste purifying capacity of the soil
b) clogging of pores in soil due to excessive application of sewage to land, obstructing aeration and leading to septic conditions
c) toxicity of sewage interfering with response to treatment
d) destruction of aquatic flora and fauna due to gross pollution of receiving bodies of water by sewage
45) For the combined sewerage system, egg-shaped sewers are preferred because
a) their construction is economical
b) they are structurally more stable
c) they offer good flow velocity during
d) their maintenance is easier
46) Traps are used in household drainage systems to
a) provide a partial vacuum
b) restrict the flow of water
c) prevent entry of foul gases in the house
d) trap the solid wastes
47) Area method of land filling is most suitable when
a) natural or artificial depressions exist
b) area is unsuitable for excavation of trenches
c) adequate depth of cover material is available at the site
d) the water table is near the surface
48) In transition of sewers from smaller diameter sewers to larger diameter sewers, the continuity of sewers is maintained at the
a) crown of the sewers
b) bottom of the concrete bed of sewers
c) inverts of the sewers
d) hydraulic gradients of the sewers
49) Which one of the following would contain water with the maximum amount of turbidity?
a) oceans
b) wells
c) lakes
d) rivers
50) The waste stabilization ponds can be
a) aerobic
b) anaerobic
c) facultative
d) any of the above
51) Eutrophication of water bodies is caused by the
a) excessive discharge of nutrients
b) excessive discharge of chlorides
c) discharge of toxic substances
d) excessive discharge of suspended solids
52) Zero hardness of water is achieved by
a) ion exchange method
b) using lime soda process
c) excess lime treatment
d) using excess alum dosage
53) Self-purification of running streams may be due to
a) dilution, oxidation and coagulation
b) sedimentation, oxidation and coagulation
c) dilution, sedimentation and coagulation
d) dilution, sedimentation and oxidation sedimentation
54) In the design of storm sewers, “time of concentration” is relevant to determine the
a) time of travel
b) rainfall intensity
c) velocity in the sewer
d) area served by the sewer
55) In the oxidation ditch, the excess sludge is taken to
a) anaerobic digester
b) aerobic digester
c) incinerator
d) drying beds
56) Aerosol is
a) carbon particles of mictoscopic size
b) finely divided particles of ash
c) diffused liquid particles
d) dispersion of small solid or liquid particles in gaseous media
57) Water present in an artesian aquifer is usually.
a) above atmospheric pressure
b) at atmospheric pressure
c) at 0.5 times of the atmospheric
d) at sub atmospheric pressure
58) A commonly used hand pump is the
a) axial flow pump
b) centrifugal pump
c) rotary pump
d) reciprocating pump
59) The trap used for a water closet is called
a) intercepting trap
b) p- trap
c) gully trap
d) anti- siphon trap
60) The controlling design parameter in the design of all settling tanks is:
a) depth
b) detention time
c) percent removal of suspended solids
d) overflow rate
