Q.1

Asbestos pipes are joined by means of

  • flanged joint
  • flexible joint
  • dresser coupling joint
  • simplex joint
  • socket and spigot joint.
Q.2

Efficiency of removing bacterias from raw water by a slow sand filter, is

  • 80% to 81%
  • 85% to 86%
  • 90% to 97%
  • 98% to 99%.
Q.3

For plain chlorination of water, the quantity of chlorine used, is

  • 0.1 mg/litre
  • 0.2 mg/litre
  • 0.3 mg/litre
  • 0.4 mg/litre
  • 0.5 mg/litre.
Q.4

Pick up the correct statement from the following :

  • Due to boiling, the bacterias present in water can be destroyed
  • Lime may be used for softening hard water
  • Excess lime when added to water, raises the pH value of water
  • the bacterias do not survive in water having pH value exceeding 9.5
  • All the above.
Q.5

The superimposed load transmitted to the pipe, is generally evaluated by Bousiness formula

Q.6

The type of joint generally used in cast iron pipes, is

  • socket and spigot joint
  • flanged joint
  • dresser coupling joint
  • flexible joint
  • all the above.
Q.7

The flow of water gets retarded, in

  • settling tank
  • sedimentation tank
  • clarifer
  • sedimentation basin
  • all the above.
Q.8

Pick up the correct statement from the following :

  • The precipitation during its travel in atmosphere dissolves certain gases
  • Rain water which percolates through the ground, is free from suspended materials
  • Under ground water may dissolve minerals and salts present in the earth's layers
  • Small quantities of iron, calcium and magnesium dissolved in water, may be useful for human health
  • All the above.
Q.9

For the prediction of future population of a city, the factor to be considered, is

  • births
  • deaths
  • migrants
  • all the above.
Q.10

Rapid sand filter

  • should be preceeded by coagulation and sedimentation
  • uses rapid sand as filter media
  • is used after slow sand filtering has been done
  • can combine disinfection also.
Q.11

The type of joint generally used in cast iron pipes, is

  • socket and spigot joint
  • flanged joint
  • dresser coupling joint
  • flexible joint
  • all the above.
Q.12

In a well planned city, the layout of distribution pipes generally adopted, is

  • grid-iron system
  • interlaced system
  • reticulation system
  • all the above.
Q.13

Detention time for plain sedimentation tank usually ranges from

  • 2 to 4 hours
  • 4 to 8 hours
  • 6 to 10 hours
  • 8 to 12 hours
  • 12 to 16 hours.
Q.14

Abyssinian tube well is a special type of

  • slotted type wells
  • cavity type wells
  • strainer type well
  • none of these.
Q.15

De-chlorination is followed by

  • post-chlorination
  • pre-chlorination
  • double-chlorination
  • super-chlorination.
Q.16

Water may contain

  • bicarbonate alkalinity
  • carbonate alkalinity
  • hydroxide alkalinity
  • caustic alkalinity
  • all the above.
Q.17

The intake opening is generally covered by a screen to prevent entry of debris etc. and its level is kept

  • at the level of water of the source
  • at the bottom of water of the source
  • at about 2.5 m above the bottom
  • none of these.
Q.18

Surcharge storage zone of a reservoir, is

  • below dead storage
  • between dead storage and useful storage
  • above useful storage
  • also known as valley storage.
Q.19

Air inlet valve in water mains, is generally provided at

  • summit of the pipe
  • upstream of sluice valve
  • down stream of sluice valve
  • valley of the pipe
  • both (a) and (c) of above.
Q.20

The maximum permissible chloride content in treated water of public water supplies should not exceed

  • 50 P.P.M.
  • 100 P.P.M.
  • 150 P.P.M.
  • 200 P.P.M.
  • 250 P.P.M.
Q.21

An ideal sand for filters should be

  • free from dirt and other impurities
  • uniform in nature and size
  • hard and resistant
  • all the above.
Q.22

Pick up the correct statement from the following :

  • Large solids carried along the river bed, is known as bed load
  • The bigger suspended particles get deposited in the head reaches of the reservoir
  • The fine sediment deposits are generally near the face of the dam
  • Deposition of sediment in the reservoir, reduces the capacity of the reservoir
  • All the above.
Q.23

Pick up the correct statement from the following :

  • Copper pipes are highly resistant to acidic and alkaline water
  • Wrought iron pipes are lighter than cast iron pipes
  • Wrought iron pipes corrode quickly and are less durable
  • Wrought iron pipes coated with zinc, are called galvanised iron pipes
  • All the above.
Q.24

Air valves are generally provided in pressure pipes of water supply

  • at pipe junctions
  • at summits
  • at low points
  • near service pipes.
Q.25

Chlorination of water does not remove

  • ammonia content
  • B.O.D.
  • organic matter content
  • dissolved oxygen.
Q.26

The bed slope in slow sand filters, is generally kept

  • 1 in 50
  • 1 in 75
  • 1 in 100
  • 1 : 200
Q.27

The valve fitted closely in a recess against an opening in a pipe, is generally

  • wedge shaped circular disc
  • spherical disc
  • parallelopiped disc
  • conical shaped circular disc.
Q.28

Pick up the correct statement from the following :

  • The ratio of the total sediment deposited in the reservoir to the total sediment flowing in the river, is called trap efficiency
  • The ratio of the reservoir capacity to the total inflow of water in it, is generally called capacity inflow ratio
  • Small capacity reservoirs on large rivers generally, silt less
  • Large capacity reservoirs on small rivers generally silt more
  • All the above.
Q.29

Most important method for calculating discharge for planning a water supply project, is

  • velocity area method
  • weir or spillway method
  • use of venturi-meter
  • using power plant consumption
  • none of these.
Q.30

A pressure conduit carrying water beneath a stream or a canal, is known as

  • sag
  • depressed pipe
  • inverted syphon
  • all the above.
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