Q.1

If four fires break out in a city of populationlakhs and if each hydrant has three streams and duration of each fire is four hours, the total quantity of water required, is

  • 1880 kilo litres
  • 2880 kilo litres
  • 3880 kilo litres
  • 4880 kilo litres.
Q.2

Turbidity of raw water is a measure of

  • suspended solids
  • acidity of water
  • B.O.D.
  • none of these.
Q.3

By boiling water, hardness can be removed if it is due to

  • calcium sulphate
  • magnesium sulphate
  • calcium nitrate
  • calcium bicarbonate
  • none of these.
Q.4

The maximum permissible nitrites in public water supplies, is

  • Nil
  • 0.5 P.P.M.
  • 1.0. P.P.M.
  • 1.5 P.P.M.
  • 200 P.P.M.
Q.5

Time of concentration

  • is the time taken, for precipitation
  • duration of rainfall.
  • time taken for all the ran off to reach the drain
  • time taken for the storm water to travel from the most remote point to the drain.
Q.6

Pick up the correct statement from the following :

  • Excess quantities of iron and manganese in water, cause discolouration of clothes
  • Lead and barium salts have toxic effect
  • Arsenic and selenium are poisonous to human health
  • Higher copper content affects the lungs
  • All the above.
Q.7

The fire demand of a city may be worked out by

  • Kuichling's formula
  • Freeman formula
  • Under Writers formula
  • Bustan's formula
  • All the above.
Q.8

A high velocity of wash water is required for

  • rapid gravity filter with strainers
  • rapid gravity filter without strainers
  • slow sand filter with strainers
  • slow sand filter without strainers
  • none of these.
Q.9

Pick up the incorrect statement from the following regarding fire hydrants

  • Fire hydrants are fitted in water mains at 100 m to 150 m apart at fire
  • The minimum water pressure hydrants, is kept 1.5 kg/cm2
  • The water at pressure 1 to 1.5 kg/cm2 is made available for 4 to 5 hours for constant use
  • None of these.
Q.10

Aeration of water is done to remove

  • odour
  • colour
  • bacterias
  • hardness
  • turbidity.
Q.11

Water supply includes

  • collection, transportation and treatment of water
  • distribution of water to consumers
  • provision of hydrants for fire fighting
  • mains, sub-mains and branch lines of water supply
  • all the above.
Q.12

For determining the velocity of flow of underground water, the most commonly used non-empirical formula is

  • Darcy's formula
  • Slichter's formula
  • Hazen's formula
  • Lacy's formula.
Q.13

In distribution pipes, drain valves are provided at

  • lower point
  • higher point
  • junction points
  • any where.
Q.14

The specific retention is least in case of

  • Clay
  • Sand
  • Silt
  • Coarse gravel.
Q.15

The yield of a rapid gravity filter as compared to that of slow sand filter, is

  • 10 times
  • 15 times
  • 20 times
  • 30 times
  • 35 times.
Q.16

Corrosion of well pipes may not be reduced by

  • reducing the draw down and the pumping rate
  • reducing the flow velocity
  • using thicker pipes
  • using screens having larger area of openings
  • none of these.
Q.17

Surge tanks are used

  • for storage water
  • to increase the velocity in a pipeline
  • as overflow valves
  • to guard against water hammer.
Q.18

B.O.D. of treated water should be

  • 10 ppm
  • 25 ppm
  • 20 ppm
  • 30 ppm
  • Nil.
Q.19

Corrosion of well pipes may not be reduced by

  • reducing the draw down and the pumping rate
  • reducing the flow velocity
  • using thicker pipes
  • using screens having larger area of openings
  • none of these.
Q.20

As per IS : 1172-water required per head per day for average domestic purposes, is

  • 50 litres
  • 65 litres
  • 85 litres
  • 105 litres
  • 135 litres.
Q.21

In slow sland filters, the turbidity of raw water can be removed only up to

  • 60 mg/litre
  • 75 mg/litre
  • 100 gm/litre
  • 150 mg/litre.
Q.22

Water supply includes

  • collection, transportation and treatment of water
  • distribution of water to consumers
  • provision of hydrants for fire fighting
  • mains, sub-mains and branch lines of water supply
  • all the above.
Q.23

For determining the velocity of flow of underground water, the most commonly used non-empirical formula is

  • Darcy's formula
  • Slichter's formula
  • Hazen's formula
  • Lacy's formula.
Q.24

Biochemical Oxygen Demand (B.O.D.) of safe drinking water must be

  • nil
  • 5
  • 10
  • 15
  • 20
Q.25

Acidity in water is caused due to

  • Mineral acids
  • Free CO2
  • Iron sulphate
  • Aluminium sulphate
  • All the above.
Q.26

Gravity conduits

  • carry water under gravity
  • follow the hydraulic gradient line
  • are carried on trestles in valleys and depressions
  • are carried through tunnels in deep cuttings
  • All the above.
Q.27

Pick up the correct statement from the following :

  • For determination of small colour intensities, tintometer is generally used
  • The odour of water sample is generally measured by a term called odour intensity
  • The colour of water sample may be detected by Nessler tube
  • Specific conductivity of water measures the amount of dissolved salt
  • All the above.
Q.28

The most ideal disinfectant used for drinking water throughout the world, is

  • alum
  • lime
  • chlorine
  • nitrogen
  • ammonia.
Q.29

Carbonates in water produce

  • temporary hardness
  • permanent hardness
  • acidity
  • alkanity.
Q.30

Before constructing a dam, the factor to be considered for controlling sedimentation, is

  • selection of dam site
  • construction of check dams
  • providing vegetation screens
  • providing under-sluices in the dam
  • All the above.
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