Quiznetik

Water Supply Engineering | Set 2

1. In which unit operation, gases are released or absorbed in the water?

Correct : A. gas transfer

2. How many types of aerators are commonly used in the treatment of water?

Correct : C. 4

3. Which of the following process is used to remove the colloidal particles from water?

Correct : B. chemical coagulation

4. Flocculation of iron from water by the addition of lime is an example of which of the following process?

Correct : A. chemical precipitation

5. In which unit operation objectionable solutes are converted into unobjectionable forms without removal?

Correct : C. solute stabilization

6. In which form of solute stabilization, hydrogen sulfide in water is oxidized into sulfate?

Correct : A. chlorination

7. Which form of solute stabilization occurs when water passes through limestone?

Correct : B. liming

8. In which process, excess lime is converted into bicarbonate?

Correct : C. re-carbonation

9. By which process, odour producing substances is oxidized?

Correct : D. super-chlorination

10. Solids are removed from the water by which of the following unit operation?

Correct : D. solids transfer

11. Dealkalization results in removal of all the ions from the water.

Correct : B. false

12. Organic contaminants are removed from the water by the process of

Correct : D. adsorption

13. is an operation designed to force agitation in the fluid and induce coagulation.

Correct : B. flocculation

14. What is the dimension formula of mean velocity gradient?

Correct : A. 1/t

15. What is the normal value of the detention period adopted in a flocculator for design purpose?

Correct : A. 30min

16. The design value of the velocity of flow in a flocculator is

Correct : A. 0.2-0.8m/s

17. What is the detention period of a clarifier used in the treatment of water?

Correct : C. 3hours

18. The pulsator clarifier is a type of

Correct : B. vertical flow sludge tank

19. Which device solved the problem of unstable hydraulic conditions and operation of sludge removal equipment?

Correct : C. tube settler

20. In which device, the primary mixing is followed by a secondary reaction zone resulting in formation of sludge blanket?

Correct : D. solid contact clarifier

21. In which type of tube settler, tubes are slightly inclined in the direction of normal flow?

Correct : D. horizontal tube settler

22. Ion exchange units are known as

Correct : B. water softeners

23. Water softener units work most efficiently with particulate water.

Correct : B. false

24. Which of these have a negative electrical charge?

Correct : D. chloride

25. The ions with opposite charge can be exchanged.

Correct : B. false

26. While designing the demineralisation plant what is considered as the weak acidic cation load?

Correct : A. alkaline hardness

27. While designing the demineralisation plant what is considered as the strong acidic cation load?

Correct : B. alkaline hardness + ema

28. While designing the demineralisation plant what is considered as the strong basic anion load?

Correct : D. silica+co2+ alkalinity+ema

29. While designing the demineralisation plant what is considered as the weak basic anion load?

Correct : C. ema

30. When is strong basic anion not necessary?

Correct : A. silica is nil

31. When the hardness and alkalinity are around 30% what should be used?

Correct : C. wac, sac

32. In case along with silica, there is high content in sulphide and chloride what should be used?

Correct : B. wba and sba

33. What is the preferred regenerant in case of cation exchanger?

Correct : A. hcl

34. What is the preferred regenerant in case of anion exchanger?

Correct : B. naoh

35. For obtaining Silica<5 ppm which of these should be utilized?

Correct : A. sba followed by mixed be

36. In which year was the Ferrosand process patented?

Correct : B. 1965

37. What is the permitted concentration of manganese in drinking water?

Correct : C. 50 g/l

38. What is the permitted concentration of arsenic in drinking water?

Correct : A. 10 g/l

39. What is the minimum time of aeration?

Correct : C. 60 minutes

40. What is the tank volume of aeration for water flow of 50m3/h?

Correct : B. 50 m3

41. At what pH should the water be maintained?

Correct : B. 7.5

42. The aeration system will decrease the redox potential of the water.

Correct : B. false

43. What is the minimum required redox potential of water?

Correct : B. 200 mv

44. Manganese oxidation requires a high oxidation potential.

Correct : A. true

45. What is the desirable bed depth for AFM filtration?

Correct : B. 1200 mm

46. What is the maximum allowable flow for backwash?

Correct : C. 60 m/hr

47. The fluoride concentration for prevention of dental caries is

Correct : A. 1mg/l

48. In which process, the fluoride content of water is raised?

Correct : B. fluoridation

49. Which of the following is not used as a fluoride compound?

Correct : D. sodium fluro carbonate

50. Which of the following is the pure compound?

Correct : A. sodium fluoride

51. Fluorides in solution form are preferred over powdered form for fluoridation.

Correct : B. false

52. What happens when water contains 8-20 ppm of fluoride concentration?

Correct : B. crippling fluorosis

53. The process of reducing the fluoride content from water is called

Correct : C. defluoridation

54. Which of the following is not used for defluoridation?

Correct : B. copper sulfate

55. Which material is used in contact filters for the removal of fluorides?

Correct : C. synthetic tri-calcium phosphate

56. Which material is used for removing fluorides from hard water containing 3ppm of fluorides?

Correct : A. lime

57. Fluorex is a special mixture of

Correct : B. tri-calcium phosphate and hydroxyapatite

58. Which of the following is not a component of plumbing water supply system?

Correct : A. washbasin

59. Which of the following is not a component of the plumbing drainage system?

Correct : B. taps

60. Light gauge copper tubes are used for general purpose work where the pressure is not more than 0.15 N/mm2.

Correct : A. true

61. Which of the following is not true about lead pipes?

Correct : B. they have a low hydraulic coefficient of flow

62. Which of the following is not true about plastic pipes?

Correct : D. plastic pipes are corrosive

63. is used to measure flows to domestic buildings.

Correct : D. water meter

64. is used to measure the flow velocity across a cross-section with a known area.

Correct : A. inferential meter

65. Inferential meters can be used for both low and high flows.

Correct : B. false

66. The method of distribution of water is divided into how many types?

Correct : C. 3

67. In which of the following distribution system, the clean water flows entirely under gravity?

Correct : A. gravity system

68. The pressure in the distribution mains does not depend on

Correct : D. quality of water

69. There is a 8 storey residential building in Lucknow. What is the pressure in the distribution mains?

Correct : B. 5kg/cm2

70. The velocity of water in a 10 cm diameter pipe should be

Correct : C. 0.9m/sec

71. In which system of water supply, water is available for 24 hours but uneconomically used?

Correct : A. continuous supply

72. In which system of water supply, water is supplied only during fixed hours of the day?

Correct : C. intermittent supply

73. The velocity of water in the pipe is 1.8m/Sec. What is the diameter of pipe used?

Correct : D. 40cm

74. The hourly demand rate is constant throughout the day.

Correct : B. false

75. According the mass curve method, the storage capacity is defined as

Correct : D. maximum excess of supply + maximum excess of demand

76. causes hoop tension in pipe shell.

Correct : A. internal water pressure

77. The water supply pipes are buried underground. The load on the buried pipe due to earth filling is given by

Correct : C. w = c*y*b2

78. Which of the following stress in pipe depends on temperature?

Correct : D. temperature stress

79. Pipe corrosion can be minimized by

Correct : D. removal of dissolved oxygen

80. How many types of pumps are present?

Correct : B. 2

81. Submersible pumps require high maintenance.

Correct : B. false

82. What is the minimum diameter of pipes used for drainage of waste water?

Correct : B. 75 mm

83. What is the wastewater from kitchen sinks called?

Correct : A. grey water

84. What is the water from urinals called?

Correct : A. black water

85. What is the minimum diameter of the pipe used to collect black water?

Correct : C. 100 mm

86. What is the recommended slope ratio for soil water pipes?

Correct : D. 1:40

87. Grease should not be allowed to enter the normal drainage system.

Correct : A. true

88. is used to clean blockage in the line.

Correct : C. inspection chamber

89. What is the shape of the septic tank?

Correct : B. rectangle

90. What is the percentage of purification of septic tank effluent?

Correct : C. 70%

91. should not be placed near water body.

Correct : B. soak pit