Q.1

The pH value of water fit for drinking, is

  • 13
  • 11
  • 9
  • 7
  • 5
Q.2

Bacterias which can survive with or without free oxygen, are known

  • aerobic bacterias
  • anerobic bacterias
  • facultative bacterias
  • none of these.
Q.3

To remove very fine suspended particles from water, the method adopted is

  • screening
  • sedimentation
  • boiling
  • filtration.
Q.4

The average domestic consumption under normal conditions in an Indian city per day per person, is

  • 105 litres
  • 115 litres
  • 125 litres
  • 135 litres
  • 150 litres.
Q.5

Pick up the incorrect statement from the following :

  • Iron salts produce heavy flocs and hence remove more suspended matter
  • Iron salts remove hydrogen sulphides
  • Iron salts can be used over a limited range of pH values
  • Iron salts impart corrosiveness to water.
Q.6

Open channels supported over tres-les, are generally known as

  • raised canals
  • acqueducts
  • syphons
  • flumes.
Q.7

For 3.x 10-2 cumecs discharging from a well, a pump is installed to lift water against a total head ofm. The minimum required horse power, is

  • 10 H.P.
  • 15 H.P.
  • 18 H.P.
  • 20 H.P.
  • 25 H.P.
Q.8

Perched acquifers generally occur

  • below water table
  • above water table
  • in acquicludes
  • in artesian acquifers
  • none of these.
Q.9

Pick up the correct statement from the following :

  • If ports are closed, the dry intake towers will not have any water
  • Even if ports are closed, the wet intake tower will have water filled up to reservoir level
  • The dry intake towers are generally constructed with heavier construction to resist buoyant forces
  • No buoyant force acts on wet intake towers
  • All the above.
Q.10

The level of underground water is called

  • water level
  • water table
  • negative level
  • invert level.
Q.11

At break point of chlorination,

  • chlorine is used to oxidise
  • residual chloride is zero
  • residual chloride is maximum
  • residual chlorine reappears.
Q.12

Plain chlorination is used for water

  • with turbidities less than 20 mg/litre
  • obtained from clear lakes
  • consumed during emergencies
  • supplies to armies during war
  • all the above.
Q.13

Pick up the incorrect statement from the following :

  • The water entering the slow sand filters should be treated by 9.386 coagulants
  • The depth of water on the filter should be twice the depth of the filter sand
  • When the filter head is 0.75 times the depth of filter sand, the water obtained is purest
  • The cleaning of slow sand filters is done by back washing
  • All the above.
Q.14

From the surface of reservoir, evaporation may be minimised by sprinkling

  • Spirit
  • Hydrochloric acid
  • Cetyl alcohol
  • Methane
  • None of these.
Q.15

Run off is the quantity of water which flows

  • in sewer pipes
  • due to leakage in pipes
  • in rivers
  • none of these.
Q.16

The pH value of water fit for drinking, is

  • 13
  • 11
  • 9
  • 7
  • 5
Q.17

The percentage of chlorine in fresh bleaching powder is roughly

  • 50 to 60
  • 30 to 35
  • 40 to 50
  • 20 to 25
Q.18

For least effect on the water table, the tube wells must be dug one in every

  • 0.5 sq km
  • 0.75 sq km
  • 1.0 sq km
  • 1.25 sq km
  • 1.5 sq km.
Q.19

S1 and S2 are the draw downs in an observation well at times t1 and t2 after pumping. For discharge Q and coefficient of transmissibility T, the relationship, is

Q.20

Silt storage is the same as

  • dead storage
  • live storage
  • effective storage
  • none of these.
Q.21

While designing a water supply of an industrial township, industrial and commercial water demand of total supply, is assumed

  • 10%
  • 10 to 15%
  • 15 to 20%
  • 20 to 25%.
Q.22

Per capita demand of water is calculated in litres

  • per person per day
  • per person per month
  • per person per year
  • none of these.
Q.23

The difference in the reservoir level and the lowest point of the water mains ism. The expected pressure due to water hammer is 7.5 kg/cm2 in a pressure conduit of diameter 1 m. Assuming the efficiency of the riveted joints of the pipe as 0.6 and minimum cover 3 mm for corrosion, the thickness of the pipe materials, is

  • 10 mm
  • 15 mm
  • 20 mm
  • 25 mm
  • 30 mm.
Q.24

The head against which the motor works for lifting water, is

  • maximum depth of water table below ground level
  • maximum depression head
  • velocity head
  • frictional losses in the delivery pipe
  • all the above.
Q.25

Underground water is obtained from

  • rains
  • rivers
  • lakes
  • reservoirs
  • springs.
Q.26

m and n are monsoon duration factor and catchment factor respectively. If P is yearly rainfall in cm, runoff can be calculated by

  • velocity area method
  • weir or spillway method
  • use of venturi-meter
  • using power plant consumption
  • none of these.
Q.27

Gravity conduits are generally in the form of

  • canals
  • flumes
  • aqueduct
  • tunnels
  • all the above.
Q.28

The head against which the motor works for lifting water, is

  • maximum depth of water table below ground level
  • maximum depression head
  • velocity head
  • frictional losses in the delivery pipe
  • all the above.
Q.29

Higher yield may be expected from

  • gravity springs
  • surface springs
  • artesian springs
  • all the above.
Q.30

In plain sedimentation tanks under normal conditions, impurities are removed upto

  • 60%
  • 70%
  • 80%
  • 90%.
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