Q.1

Increase in population of a rapidly growing city, may be estimated by

  • arithmetical mean method
  • geometrical method
  • incremental increase method
  • graphical comparison method.
Q.2

The formula for the head loss in conduits is generally known as

  • Hazen-William's formula
  • Manning's formula
  • Darcy-Weisbach formula
  • Nikuradse formula.
Q.3

The most commonly used chemical for dechlorination of water, is

  • sodium thiosulphate
  • sodium bisulphate
  • sodium sulphite
  • sulphur-dioxide
  • all the above.
Q.4

Disappearance of pink colour of water of a well due of KMnO4 indicates that water contains

  • acidity
  • alkalinity
  • turbidity
  • organic matter
  • all the above.
Q.5

Mostly used coagulant, is

  • chlorine
  • alum
  • lime
  • bleaching powder.
Q.6

The maximum permissible colour for domestic supplies based on cobalt scale, is

  • 5 ppm
  • 10 ppm
  • 15 ppm
  • 20 ppm
  • 25 ppm.
Q.7

Mathamoglobinemia, or blue baby disease is caused due to

  • chlorides
  • nitrites
  • nitrates
  • sulphides.
Q.8

The formula for the head loss in conduits is generally known as

  • Hazen-William's formula
  • Manning's formula
  • Darcy-Weisbach formula
  • Nikuradse formula.
Q.9

After cleaning a slow sand filter, the filtered water is not used for

  • 6 hours to 12 hours
  • 12 hours to 18 hours
  • 18 hours to 24 hours
  • 24 hours to 36 hours
  • 48 hours.
Q.10

The prescribed hardness limit of potable water ranges between

  • 50 to 75 P.P.M.
  • 75 to 115 P.P.M.
  • 100 to 150 P.P.M.
  • 150 to 200 P.P.M.
  • none of these.
Q.11

Water is supplied from the source to the treatment plant under gravity in

  • Calcutta
  • Delhi
  • Madras
  • Bombay.
Q.12

Shales are

  • porous
  • permeable
  • porous and permeable
  • porous but not permeable
  • neither porous nor permeable.
Q.13

The dilution ratio at which the odour is hardly detectable is generally called threshold odour number and for public supplies it should not exceed

  • 3
  • 5
  • 7
  • 9
  • 10
Q.14

The main process to purify water by filtration, is

  • mechanical straining
  • flocculation and sedimentation
  • biological metabolism
  • electronic change
  • all the above.
Q.15

A pressure conduit laid under ground, may not be subjected to

  • internal pressure of water
  • pressure due to external load
  • longitudinal temperature stress
  • longitudinal stresses due to unbalanced pressure to bends
  • none of these.
Q.16

The standard B.O.D. at 20&Deg;C, is taken for the consumption in

  • one day
  • 2 days
  • 3 days
  • 4 days
  • 5 days.
Q.17

For centrifugal pumps

  • initial cost is low
  • limited space is required
  • the discharge obtained is steady and non-pulsating
  • all the above.
Q.18

The standard B.O.D. at 20&Deg;C, is taken for the consumption in

  • one day
  • 2 days
  • 3 days
  • 4 days
  • 5 days.
Q.19

Water is distributed to consumers by gravitational system, in

  • Dehradun
  • Bombay
  • Delhi
  • Calcutta
  • Both (a) and (b).
Q.20

Velocity of flow of water in plain sedimentation water tank, is normally kept

  • 3 cm/minute
  • 10 cm/minute
  • 20 cm/minute
  • 30 cm/minute
  • 40 cm/minute.
Q.21

The joint used for joining the plain ends of cast iron pipes, is

  • flanged joint
  • socket and spigot joint .
  • dresser coupling joint
  • flexible joint
  • expansion joint.
Q.22

The period of cleaning of a slow sand filter, is usually

  • 5 to 10 days
  • two weeks to three weeks
  • one month to three months
  • three months to six months
  • one year.
Q.23

If G is the specific gravity of particles of diameter d, the velocity of settlement V in still water at T°C, according to Stoke's law, is

  • none of these.
Q.24

The cast iron pipes for water supply system are used for

  • durability
  • strength
  • easy connection
  • low maintenance cost
  • all the above.
Q.25

In distribution pipes, air valves are provided at

  • lower points
  • junction points
  • higher points
  • any where.
Q.26

The most important and widely used tube well in India, is

  • strainer well
  • cavity well
  • slotted well
  • perforated pipe well.
Q.27

Pick up the incorrect statement from the following. The source of surface water is from

  • streams and rivers
  • storage reservoirs
  • springs
  • ponds and lakes
  • none of these.
Q.28

litres of water per person per day, is provided in

  • nurses homes
  • hostels
  • residential schools
  • all the above.
Q.29

Growth of population can be conveniently represented by

  • an arithmetical curve
  • a semi-logarithmic curve
  • a logistic curve
  • a straight line curve
  • all the above.
Q.30

The bacterias which may survive with or without free oxygen, are called

  • Aerobic bacterias
  • Anaerobic bacterias
  • Faculative bacteria's
  • None of these.
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