Q.1

Hard water for public water supply is discarded because

  • it consumes more soap
  • it contains lot of turbidity
  • it contains pathogenic bacterias
  • it possesses bad taste and odour
  • none of these.
Q.2

Gravity conduits for carrying water from the source are

  • canals
  • flumes
  • acqueducts
  • all the above.
Q.3

Rapid gravity filter can only remove turbidity of water upto

  • 15 to 25 gm/litre
  • 25 to 30 gm/litre
  • 30 to 35 cm/litre
  • 35 to 40 gm/litre
  • 50 gm/litre.
Q.4

E. Coli bacterias die in water having pH greater than

  • 5.5
  • 6.5
  • 7.5
  • 8.5
  • 9.5
Q.5

The main disadvantage of hard water, is

  • greater soap consumption
  • scaling of boilers
  • corrosion and incrustation of pipes
  • making food tasteless
  • all the above.
Q.6

Surface water is obtained from

  • well
  • springs
  • artesian well
  • rain.
Q.7

Pick up the correct statement from the following regarding radial flow centrifugal pumps :

  • These are provided with volute type or turbine type casings
  • In involute type of radial flow centrifugal pump, the impeller discharges into a gradually expanding spiral casing
  • In turbine type of radial flow centrifugal pumps, the impeller is surrounded by stationary guide vanes to reduce the velocity of water
  • The efficiency of turbine type of radial flow centrifugal pump, is always higher than that of volute type
  • All the above.
Q.8

Continuous flow of water can be expected from

  • gravity springs
  • surface springs
  • artesian springs
  • none of these.
Q.9

Pick up the correct statement from the following :

  • The amount of rainfall in 24 hours, is known as daily rainfall
  • The amount of rainfall in one year, is known as annual rainfall
  • The rain cycle period in India is taken as 35 years
  • The ratio of the actual rainfall in the year to the normal rainfall at a place, is called index of the wetness
  • All the above.
Q.10

Check valves are installed

  • on the delivery side of the pumping set
  • at the interconnections between polluted water system and a potable water system
  • both (a) and (b)
  • neither (a) nor (b).
Q.11

An area is declared drought affected if its mean rainfall is less than

  • 50%
  • 60%
  • 75%
  • 80%
  • 85%.
Q.12

Hardness of water is caused due to

  • calcium sulphate
  • magnesium sulphate
  • calcium nitrates
  • calcium bicarbonates
  • all the above.
Q.13

Quality of water is said to be good if it is

  • free from suspended matter
  • colourless
  • free from pathogenic organism
  • tasteless
  • all the above.
Q.14

The maximum hourly consumption, is generally taken as

  • 110%
  • 120%
  • 130%
  • 140%
  • 150%.
Q.15

The best process of disinfection of public water supply, is by

  • boiling
  • chlorination
  • adding lime
  • adding zone.
Q.16

The best quality of filter material is obtained from quartzite if it does not loose weight when placed in hydro-chloric acid forhours, more than

  • 5%
  • 8%
  • 10%
  • 12%
  • 15%.
Q.17

Flow through period, in sedimentation tanks, is

  • equal to detention period
  • more than detention period
  • less than detention period
  • detention period divided by displacement efficiency
  • none of these.
Q.18

Pick up the incorrect statement from the following :

  • An impervious layer a few metres below the water table in the sub-soil, is generally called Mota layer (6) Mota layer is very useful to give structural support to open deep wells
  • A bore hole is generally provided in the mota layer for deep wells
  • Shallow wells are always of less depth as compared to deep wells
  • None of these.
Q.19

A city supply includes

  • domestic water demand
  • industrial and commercial water demands
  • demand for public uses and fire
  • water losses
  • all the above.
Q.20

Pick up the correct statement from the following :

  • A hydrograph is a plot of discharge versus time
  • A mass curve is a plot of accumulated flow versus time
  • The mass curve continuously rises
  • The slope of the mass curve at any time is a measure of the inflow rate at that time
  • All the above.
Q.21

If discharge of a pump is 0.cumecs, the economic diameter of pipe, is

  • 0.488 m
  • 4.88 cm
  • 0.488 cm
  • 4.88 m
  • none of these.
Q.22

Normal values of overflow rate for plain sedimentation tank, is

  • 250 to 500 litres/hr/m2
  • 500 to 750 litres/hr/m2
  • 750 to 1000 litres/hr/m2
  • 1000 to 1250 litres/hr/m2.
Q.23

The main draw-back of centrifugal pump, is

  • necessity of priming
  • discharge from pump varies with the load of water
  • for high heads, efficiency is low up to 50%
  • the suction lift is limited to 6 m
  • all the above.
Q.24

If intensity of rainfall in cm per hour is I, percentage coefficient of run-off is P, area of catchment in square kilometres is A, the total run-off Q, is given by

  • Q = 1.758 x 102 x API
    218-10.216-1.png
    218-10.216-2.png
  • Q = 2.758 x 102 x API
    218-10.216-1.png
    218-10.216-2.png
  • Q = 2.758 x 103 x API
    218-10.216-1.png
    218-10.216-2.png
Q.25

If intensity of rainfall in cm per hour is I, percentage coefficient of run-off is P, area of catchment in square kilometres is A, the total run-off Q, is given by

  • Q = 1.758 x 102 x API
    218-10.216-1.png
    218-10.216-2.png
  • Q = 2.758 x 102 x API
    218-10.216-1.png
    218-10.216-2.png
  • Q = 2.758 x 103 x API
    218-10.216-1.png
    218-10.216-2.png
Q.26

Mud balls may be removed by

  • breaking and washing
  • washing the filter with a solution of caustic soda
  • removing, cleaning and replacing the damaged sand
  • all the above.
Q.27

For estimating the run off of catchments, the mean value of the constant 'K' in the Khosla's formula Qy = Py - K (1.8 Ty +is

  • 1.21
  • 1.23
  • 1.25
  • 1.27
  • 1.31
Q.28

The maximum pressure to which cast iron pipes may be subjected to, is

  • 7 kg/cm2
  • 3 kg/cm2
  • 5 kg/cm2
  • 10 kg/cm2.
Q.29

For maximum alkalinity of water, pH value should be

  • zero
  • less than 7
  • more than 7
  • 14
  • 21
Q.30

Service connections to consumers houses, are generally provided with

  • copper pipes
  • hume pipes
  • galvanised iron pipes
  • P.V.C. pipes
  • none of these.
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