Water Supply Engineering Quiz | Water Supply Engineering Multiple Choice Questions and Answers

Questions
1 Pick up the correct statement from the following :
A Detention period for plain sedimentation tanks ranges between 4 to 8 hours
B Detention period for sedimentation tanks, using coagulants usually ranges between 2 to 4 hours
C The horizontally flow velocity in sedimentation tanks, is generally limited to 0.3 m/minute
D All the above.

Answer: All the above.
2 Corrosion of a pipe
A reduces its life span
B reduces its carrying capacity
C adds colour to water
D all the above.

Answer: all the above.
3 Water supply system includes
A digging a well for water
B construction of dams
C construction of canals
D entire arrangement from source to distribution.

Answer: entire arrangement from source to distribution.
4 In pressure supply mains, water hammer pressure is reduced by providing
A sluice valves
B air valves
C pressure relief valves
D none of the these

Answer: pressure relief valves
5 If pH value of water is
A 7 water it is said to be neutral
B less than 7 it is said to be acidic
C more than 7 it is said to be alkaline
D all the above.

Answer: all the above.
6 Distribution mains of any water supply, is normally designed for its average daily requirement
A 100%
B 150%
C 200%
D 225%.

Answer: 225%.
7 Economic height of a dam is the height corresponding to which
A cost of the dam per unit of storage is minimum
B amount of silting is less
C cost of dam per unit storage is maximum
D free board provided is least

Answer: cost of the dam per unit of storage is minimum
8 Most commonly used pump for lifting water in water supply mains, is
A axialflow pump
B reciprocating pump
C rotary type pump
D centrifugal pumps

Answer: axialflow pump
9 B.O.D. of treated water should be
A 10 ppm
B 25 ppm
C 30 ppm
D Nil

Answer: Nil
10 The specific retention is least in case of
A Clay
B Sand
C Silt
D Coarse gravel

Answer: Coarse gravel
11 Pick up the incorrect statement from the following regarding fire hydrants
A Fire hydrants are fitted in water mains at 100 m to 150 m apart at fire
B The minimum water pressure hydrants, is kept 1.5 kg/cm2
C The water at pressure 1 to 1.5 kg/cm2 is made available for 4 to 5 hours for constant use
D None of these

Answer: None of these
12 Pick up the correct statement from the following :
A Excess quantities of iron and manganese in water, cause discolouration of clothes
B Lead and barium salts have toxic effect
C Arsenic and selenium are poisonous to human health
D All the above

Answer: All the above
13 The transitional middle portion of a logistic curve follows
A constant rate
B first over curve
C logarithmic growth
D geometric growth

Answer: constant rate
14 Acidity in water is caused due to
A Mineral acids
B Free CO2
C Iron sulphate
D All the above

Answer: All the above
15 Biochemical Oxygen Demand (B.O.D.) of safe drinking water must be
A nil
B 5
C 10
D 20

Answer: nil
16 In slow sland filters, the turbidity of raw water can be removed only up to
A 60 mg/litre
B 75 mg/litre
C 100 gm/litre
D 150 mg/litre.

Answer: 60 mg/litre
17 As per IS : 1172-1963, water required per head per day for average domestic purposes, is
A 50 litres
B 135 litres
C 105 litres
D 65 litres

Answer: 135 litres
18 Surge tanks are used
A for storage water
B to increase the velocity in a pipeline
C as overflow valves
D to guard against water hammer

Answer: to guard against water hammer
19 The yield of a rapid gravity filter as compared to that of slow sand filter, is
A 10 times
B 15 times
C 20 times
D 30 times

Answer: 30 times
20 Aeration of water is done to remove
A odour
B colour
C bacterias
D hardness

Answer: odour
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