# 300+ TOP WATER SUPPLY Engineering Objective Questions and Answers

## WATER SUPPLY Engineering Objective Questions :-

1. If four fires break out in a city of population 40 lakhs and if each hydrant has three streams and duration of each fire is four hours, the total quantity of water required, is
A. 1880 kilo litres
B. 2880 kilo litres
C. 3880 kilo litres
D. 4880 kilo litres.
Ans: B

2. The fire demand of a city may be worked out by
A. Kuichling’s formula
B. Freeman formula
C. Under Writers formula
D. Bustan’s formula
E. All the above.
Ans: E

3. Aeration of water is done to remove
A. odour
B. colour
C. bacterias
D. hardness
E. turbidity.
Ans: A

4. 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
E. 35 times.
Ans: D

5. Disinfection of drinking water, is done to remove
A. odour
B. bacterias
C. turbidity
D. colour.
Ans: B

6. Sunlight
A. helps growth of bacterias
B. impedes growth of algae
C. increases dissolved oxygen content
D. reduces turbidity.
Ans: B

7. The expected discharge to be obtained from an open well sunk in coarse sand is 0.0059 cumec. If the working depression head of the well is 3 m, the minimum diameter of the well, is
A. 2 m
B. 2.25 m
C. 2.50 m
D. 2.75 m
E. 3.00 m.
Ans: E

8. Average annual rainfall at any station is the average of annual rainfall over a period of
A. 7 years
B. 14 years
C. 21 years
D. 28 years
E. 35 years.
Ans: E

9. Time of concentration
A. is the time taken, for precipitation
B. duration of rainfall.
C. time taken for all the ran off to reach the drain
D. time taken for the storm water to travel from the most remote point to the drain.
Ans: D

10. 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.
Ans: D

11. As per IS : 1172-1963, water required per head per day for average domestic purposes, is
A. 50 litres
B. 65 litres
C. 85 litres
D. 105 litres
E. 135 litres.
Ans: E

12. 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.
Ans: A

13. Biochemical Oxygen Demand (B.O.D.) of safe drinking water must be
A. nil
B. 5
C. 10
D. 15
E. 20
Ans: A

14. Acidity in water is caused due to
A. Mineral acids
B. Free CO2
C. Iron sulphate
D. Aluminium sulphate
E. All the above.
Ans: E

15. In distribution pipes, drain valves are provided at
A. lower point
B. higher point
C. junction points
D. any where.
Ans: A

### WATER SUPPLY Engineering Mcqs Pdf ::

16. Corrosion of well pipes may not be reduced by
A. reducing the draw down and the pumping rate
B. reducing the flow velocity
C. using thicker pipes
D. using screens having larger area of openings
E. none of these.
Ans: D

17. Asbestos pipes are
A. light in weight and easy to transport
B. highly resistant to corrosion
C. high flexible to accommodate deflection upto 12°
D. very much smooth and hydraulically efficient
E. all the above.
Ans: E

18. The maximum depth of sedimentation tanks is limited to
A. 2 m
B. 3 m
C. 4 m
D. 5 m
E. 6 m.
Ans: E

19. By boiling water, hardness can be removed if it is due to
A. calcium sulphate
B. magnesium sulphate
C. calcium nitrate
D. calcium bicarbonate
E. none of these.
Ans: D

20. For determining the velocity of flow of underground water, the most commonly used non-empirical formula is
A. Darcy’s formula
B. Slichter’s formula
C. Hazen’s formula
D. Lacy’s formula.
Ans: A

21. The least thickness of class B cast iron (spun) pipe, is
A. 7.2 mm
B. 7.9 mm
C. 8.6 mm
D. 10 mm.
Ans: C

22. According to IS : 1172-1963, a minimum of 135 litres of water capita per day, is required for
A. Boarding schools
B. Nurses home and medical quarters
C. hostels
D. all the above.
Ans: D

23. The R.L. of ground water table on the sides of a valley is 1505 m whereas R.L. of the stream water is 1475 m. If 60° slope consists of pervious soil between R.L. 1485 m to 1500 m, the gravity spring may be expected at the point of reduced level
A. 1500 m
B. 1505 m
C. 1475 m
D. 1485 m.
Ans: D

24. The factor affecting per capita demand, is
A. size of the city
B. climatic conditions
C. pressure in water mains
D. cost of water
E. all the above.
Ans: E

25. Pick up the incorrect statement from the following. The underground sources of water, is from
A. wells
B. springs
C. infiltration wells
D. storage reservoirs
E. none of these.
Ans: D

26. The specific retention is least in case of
A. Clay
B. Sand
C. Silt
D. Coarse gravel.
Ans: D