Q.1

A well is considered to be good if it is sunk into

  • Clay
  • Sand
  • Coarse gravel
  • Silt.
Q.2

Well treated water is generally supplied for

  • domestic use
  • commercial use
  • public use
  • waste water
  • all the above.
Q.3

Alum is a

  • coagulant
  • flocculant
  • catalyst
  • disinfectant.
Q.4

Pick up the incorrect statement from the following. In take of water supply should

  • be nearer to the treatment plant
  • receive water from purer zone of the source
  • be located downstream of waste water disposal point
  • remain easily accessible during floods.
Q.5

The nitrate concentration in domestic water supplies, is generally limited to

  • 10 ppm
  • 15 ppm
  • 25 ppm
  • 30 ppm
  • 45 ppm.
Q.6

Non-pathogenic bacterias cause the following water borne disease,

  • cholera
  • typhoid
  • infections hepatitis
  • none of these.
Q.7

Normal values of overflow rate for sedimentation tanks using coagulants in litres/hr/m2 , generally range between

  • 250 to 500
  • 500 to 750
  • 750 to 1000
  • 1000 to 1250
Q.8

Reciprocating pumps

  • are not suitable for variable heads
  • are four times costlier than centrifugal pumps
  • are not suitable for pumping water containing sediments
  • single stroke produce pulsating flow
  • none of these.
Q.9

Ground water from artesian wells

  • contains no suspended materials
  • contains dissolved salts
  • may be saltish and hard
  • generally require lesser treatment
  • all the above.
Q.10

Permanent hardness of water can be removed by

  • adding alum
  • adding lime
  • adding chlorine
  • boiling
  • zeolite process.
Q.11

In an artesian acquifer, the draw downs in two observation wells at distancesm, andm were found same after one hour and x hours respectively. The value of x, is

  • 2 hours
  • 4 hours
  • 9 hours
  • 16 hours.
Q.12

While selecting the location of an intake for collecting surface water, the factor considered, is

  • The intake point should be near as far as possible to the treatment plant
  • The intake point should be in purer zone of the water source
  • The intake point should be upstream of the point of disposal of waste water
  • The intake point in meandering rivers should be on concave banks
  • All the above;
Q.13

Sluice valves in main water supplies

  • are used to regulate the flow of water in pipes
  • are spaced about 5 km apart
  • are usually placed at the summits
  • all the above.
Q.14

Steel pipe are

  • suitable for withstanding high internal pressure
  • connected by riveted or welded joints
  • generally laid under ground and no expansion joint is required
  • likely to last 100 years under ordinary conditions
  • None of these.
Q.15

In a rapid sand filter, air binding is caused due to excessive

  • negative pressure
  • pressure
  • turbidity
  • water pressure
  • all the above.
Q.16

In a reservoir the average volume of sediment deposition is 0.million cubic per year. If the dead storage and total capacity of the reservoir are 8 million cubic metres andmillion cubic metres respectively,

  • the reservoir will theoretically be silted in 240 years
  • the reservoir will start reducing after 60 years
  • both (a) and (b)
  • neither (a) nor (b).
Q.17

The temporary hardness of water can be removed by

  • boiling
  • adding lime
  • adding alum
  • filtration
  • sedimentation.
Q.18

Property of earth to allow water to pass through it, is known as

  • perviousness
  • porosity
  • permeability
  • transmissibility.
Q.19

Demand for public uses in a city, does not include water required for

  • watering of public parks
  • watering of public gardens
  • sprickling on roads
  • drinking purposes.
Q.20

Dissolved carbon dioxide, can be removed from the supply main by

  • sedimentation
  • aeration
  • chlorination
  • coagulation
  • none of these.
Q.21

Aqueducts are generally designed

  • circular
  • rectangular
  • horse shoe section
  • all the above.
Q.22

The coefficient of permeability of soils, is generally expressed in

  • cm/sec
  • cm/minute
  • cm2/sec
  • cm2/minute.
Q.23

Water losses in water supply, is assumed as

  • 5%
  • 7.5%
  • 10%
  • 22.5%
  • 15%.
Q.24

If average volume of sediment deposits is one-tenth million cubic metres per year in a reservoir of total capacitymillion cubic metres, the dead storage will be filled up, in

  • 10 years
  • 15 years
  • 20 years
  • 25 years
  • 50 years.
Q.25

Rapid gravity filters

  • were developed by G.W. Fullar
  • make use of coarser sand with effective size as 0.5 mm
  • yield as high as 30 times the yield of slow sand filters
  • are fed with coagulation treated water
  • all the above.
Q.26

The chloride content of treated water for public supplies should not exceed

  • 100 ppm
  • 150 ppm
  • 200 ppm
  • 250 ppm
  • 300 ppm.
Q.27

Slow sand filter is used if maximum turbidity of raw water is less than

  • 10 gm/litre
  • 20 gm/litre
  • 30 gm/litre
  • 40 gm/litre
  • 50 gm/litre.
Q.28

Pick up the correct statement from the following :

  • Head loss in smaller size pipes at equal velocities, is less
  • Cost of pumping is less in smaller size pipes
  • Cost of smaller pipes is comparatively more
  • None of these.
Q.29

Pick up the correct statement from the following :

  • Deposition of calcium carbonate on the inside of the well pipe, causes incrustation of the pipe
  • Incrustation of the pipe reduces the discharge
  • Acidic waters cause corrosion of the pipes
  • Corrosion results due to excessive withdrawal of sand along with water
  • All the above.
Q.30

The pH value of water is kept slightly less than 7 so that hydrochloride ions may combine with ammonia ions to form

  • Mono-chloramine (NHCl)
  • Di-chloramine (NH2Cl)
  • Nitrogen trichloramine (NCl3)
  • All the above.
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