Civil Engineering - Water Supply Engineering MCQs Part 6

1. Manholes are less common in

A.
cast iron pipes

B.
steel pipes

C.
hume steel pipes

D.
R.C.C. pipes.

 Answer Option A

2. Pick up the correct statement from the following :

A.
If ports are closed, the dry intake towers will not have any water

B.
Even if ports are closed, the wet intake tower will have water filled up to reservoir level

C.
The dry intake towers are generally constructed with heavier construction to resist buoyant forces

D.
No buoyant force acts on wet intake towers

E.
All the above.

 Answer Option E

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

A.
10%

B.
10 to 15%

C.
15 to 20%

D.
20 to 25%.

 Answer Option D

4. The storage capacity of a reservoir may be divided into three zones. The lowest zone is

A.
Dead storage

B.
Useful storage

C.
Surcharge storage

D.
None of these.

 Answer Option A

5. In a rapid gravity filter

A.
raw water from the source is supplied

B.
disinfected raw water is supplied

C.
raw water passed through coagulation tank is supplied

D.
none of these.

 Answer Option C

6. In distribution pipes, air valves are provided at

A. lower points

B. junction points

C. higher points

D. any where.

 Answer Option C

7. The flow of water gets retarded, in

A. settling tank

B. sedimentation tank

C. clarifer

D. sedimentation basin

E. all the above.

 Answer Option E

8. Surcharge storage zone of a reservoir, is

A. below dead storage

B. between dead storage and useful storage

C. above useful storage

D. also known as valley storage.

 Answer Option C

9. Surface water may

A. contain large amount of impurities

B. be contaminated by impurities

C. contain disease producing bacterias

D. all the above.

 Answer Option D

10. For a city developed haphazardly, the layout of distribution pipes preferred to, is

A. ring system

B. radial system

C. grid iron system

D. dead end system.

 Answer Option D

11. Asbestos pipes are joined by means of

A. flanged joint

B. flexible joint

C. dresser coupling joint

D. simplex joint

E. socket and spigot joint.

 Answer Option D

12. Abyssinian tube well is a special type of

A. slotted type wells

B. cavity type wells

C. strainer type well

D. none of these.

 Answer Option C

13. Chlorination of water does not remove

A. ammonia content

B. B.O.D.

C. organic matter content

D. dissolved oxygen.

 Answer Option D

14. The efficiency of a pumping set, is generally assumed

A. 50%

B. 55%

C. 60%

D. 65%

E. 70%.

 Answer Option D

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

A. screening

B. sedimentation

C. boiling

D. filtration.

 Answer Option D

16. Velocity of flow of water in plain sedimentation water tank, is normally kept

A. 3 cm/minute

B. 10 cm/minute

C. 20 cm/minute

D. 30 cm/minute

E. 40 cm/minute.

 Answer Option D

17. The most important and widely used tube well in India, is

A. strainer well

B. cavity well

C. slotted well

D. perforated pipe well.

 Answer Option A

18. Pick up the correct statement from the following :

A. The precipitation during its travel in atmosphere dissolves certain gases

B. Rain water which percolates through the ground, is free from suspended materials

C. Under ground water may dissolve minerals and salts present in the earth's layers

D. Small quantities of iron, calcium and magnesium dissolved in water, may be useful for human health

E. All the above.

 Answer Option E

19. The maximum permissible chloride content in treated water of public water supplies should not exceed

A. 50 P.P.M.

B. 100 P.P.M.

C. 150 P.P.M.

D. 200 P.P.M.

E. 250 P.P.M.

 Answer Option E

20. To pump water from a water reservoir 3 m deep and maximum water level at 135 m, a pump is installed to lift water up to R.L. 175 m at a constant rate of 36, 00, 000 litres per hour. If the length of the pipe is 1506 m and f = 0.01, ignoring other minor losses and assuming the economical diameter from Lea's formula D = 1.2 Q, the water horse power of the pump is

A. 400

B. 450

C. 500

D. 580

E. 600

 Answer Option E

21. Disappearance of pink colour of water of a well due of KMnO4 indicates that water contains

A. acidity

B. alkalinity

C. turbidity

D. organic matter

E. all the above.

 Answer Option D

22. Shales are

A. porous

B. permeable

C. porous and permeable

D. porous but not permeable

E. neither porous nor permeable.

 Answer Option D

23. Water is distributed to consumers by gravitational system, in

A. Dehradun

B. Bombay

C. Delhi

D. Calcutta

E. Both (a) and (b).

 Answer Option E

24. Grade aqueducts are not allowed to run

A. full

B. th full

C. full

D. th full.

 Answer Option A

25. The type of joint generally used in cast iron pipes, is

A. socket and spigot joint

B. flanged joint

C. dresser coupling joint

D. flexible joint

E. all the above.

 Answer Option E

26. Growth of population can be conveniently represented by

A. an arithmetical curve

B. a semi-logarithmic curve

C. a logistic curve

D. a straight line curve

E. all the above.

 Answer Option C

27. In a well planned city, the layout of distribution pipes generally adopted, is

A. grid-iron system

B. interlaced system

C. reticulation system

D. all the above.

 Answer Option D

28. Air valves are generally provided in pressure pipes of water supply

A. at pipe junctions

B. at summits

C. at low points

D. near service pipes.

 Answer Option B

29. Pick up the correct statement from the following :

A. The water level in a still well, represents the ground water table level

B. The difference between water table level and the water level in a well after pumping, is called depression head

C. The surface of water table surrounding a well during pumping, forms a cone of depression

D. The distance from the centre of the well up to the place where level of water table is not affected, is called radius of influence

E. All the above.

 Answer Option E

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

A. aerobic bacterias

B. anerobic bacterias

C. facultative bacterias

D. none of these.

 Answer Option C

31. The maximum permissible colour for domestic supplies based on cobalt scale, is

A. 5 ppm

B. 10 ppm

C. 15 ppm

D. 20 ppm

E. 25 ppm.

 Answer Option D

32. The dilution ratio at which the odour is hardly detectable is generally called threshold odour number and for public supplies it should not exceed

A. 3

B. 5

C. 7

D. 9

E. 10

 Answer Option A

33. The joint used for joining the plain ends of cast iron pipes, is

A. flanged joint

B. socket and spigot joint .

C. dresser coupling joint

D. flexible joint

E. expansion joint.

 Answer Option C

34. The bacterias which may survive with or without free oxygen, are called

A. Aerobic bacterias

B. Anaerobic bacterias

C. Faculative bacteria's

D. None of these.

 Answer Option C

35. Detention time for plain sedimentation tank usually ranges from

A. 2 to 4 hours

B. 4 to 8 hours

C. 6 to 10 hours

D. 8 to 12 hours

E. 12 to 16 hours.

 Answer Option B

36. The rate of silting in a reservoir

A. is less in the beginning

B. remains constant throughout

C. is more in the beginning

D. is more in the beginning and reduces in the end

E. none of these.

 Answer Option D

37. Estimates of a water supply project depends upon the rate of water supply per capita consumption and probable population estimated at the end of the design period of

A. 5 to 10 years

B. 10 to 15 years

C. 15 to 20 years

D. 20 to 30 years

E. 25 years.

 Answer Option D

38. In centrifugal pump installation,

A. pump is properly primed before starting

B. the diameter of the pipe at inlet as well as at outlet, is kept smaller than the delivery pipe

C. the foot valve fitted at the bottom end of the suction pipe, prevents the movement of water from the pump when it is stopped

D. the motor may burn out if it is started with empty delivery pipe and with open gate valve

E. all the above.

 Answer Option E

39. Pipes are laid parallel

A. to increase the capacity of the water supply

B. to provide a means of repairing without closing water supply

C. to meet the requirement of excessive supply

D. all the above.

 Answer Option D

40. Maximum permissible colour for domestic water supplies, based on Cobalt scale, is

A. 5 P.P.M.

B. 10 P.P.M.

C. 15 P.P.M.

D. 20 P.P.M.

E. 25 P.P.M.

 Answer Option D

41. 135 litres of water per person per day, is provided in

A. nurses homes

B. hostels

C. residential schools

D. all the above.

 Answer Option D

42. For a network of distribution pipes of a proposed township shown in the below figure, the layout of distribution system, is

A. dead end system

B. grid-iron system

C. ring system

D. radial system.

 Answer Option D

43. If P is population of a city in thousands and Q is fire demand in litres per minute, for proper estimate of water, the Empirical formula is suggested by

A. National Board of fire under-writers

B. Freeman

C. Kuichling

D. None of these.

 Answer Option B

44. The gaseous form of chlorine gets converted into liquid form when subjected to a pressure of

A. 5 kg/cm2

B. 6 kg/cm2

C. 7 kg/cm2

D. 8 kg/cm2

E. 10 kg/cm2.

 Answer Option C

45. The pH value of water fit for drinking, is

A. 13

B. 11

C. 9

D. 7

E. 5

 Answer Option D

46. Pick up the incorrect statement from the following. The source of surface water is from

A. streams and rivers

B. storage reservoirs

C. springs

D. ponds and lakes

E. none of these.

 Answer Option C

47. For the prediction of future population of a city, the factor to be considered, is

A. births

B. deaths

C. migrants

D. all the above.

 Answer Option D

48. Pick up the correct statement from the following :

A. Large solids carried along the river bed, is known as bed load

B. The bigger suspended particles get deposited in the head reaches of the reservoir

C. The fine sediment deposits are generally near the face of the dam

D. Deposition of sediment in the reservoir, reduces the capacity of the reservoir

E. All the above.

 Answer Option E

49. Pick up the incorrect statement from the following :

A. The flow in strainer type wells is radial

B. The flow in cavity type wells in spherical

C. In strainer type wells, area of flow depends upon the length of the strainer pipe

D. In cavity type wells, area of flow depends upon the size of the cavity

E. None of these.

 Answer Option C

50. Water may not contain much impurities if its source is

A. reservoirs

B. stream flowing in plains

C. lakes in lower regions

D. spring along hill slopes

E. none of these.

 Answer Option D