1. Grit chambers of a sewage plant are usually changed after
Correct : C. 2 weeks
2. Low turbidity of water can be determined by
Correct : C. Baylis turbidimeter
3. High turbidity of water can be determined by
Correct : B. Jacksons turbidimeter
4. The maximum permissible hardness in water for drinking purposes should not exceed 100 ppm.
Correct : A. Correct
5. When the pH value of water is more than 7, it represents
Correct : C. alkaline
6. Copper sulphate is the most common chemical used for controlling
Correct : B. algae
7. Flush type fire hydrants remain standing above the road.
Correct : B. Incorrect
8. Rapid sand filter can remove turbidity from water upto an extent of
Correct : C. 35 to 40 ppm
9. Bio-chemical oxygen demand (B.O.D.) of safe drinking water must be
Correct : A. 0
10. Sphere shaped bacterias are called
Correct : C. cocci
11. A sewer which receives storm water, surface run-off and sewage is called a
Correct : B. combined sewer
12. The amount of oxygen consumed by sewage from an oxidising agent like potassium dichromate is termd as
Correct : B. chemical oxygen demand (C.O.D.)
13. A separate system will be favourable when
Correct : D. all of the above
14. The valve provided on the suction pipe in a tube well is
Correct : D. reflux valve
15. The equipment used for cleaning the sewers easily is called
Correct : D. scraper
16. The water obtianed from
Correct : B. springs
17. Which of the following statement is correct?
Correct : D. all of the above
18. According to Indian standards, the consumption of water per capita per day for nursing homes, boarding schools and hostels is
Correct : D. 135 litres
19. The equipment used for removing paper and rags from sewers is called
Correct : C. claw
20. Run-off is the water which flows
Correct : D. in rivers
21. In preliminary treatment of sewage, the operation which takes place, is
Correct : C. removal of lighter floating material
22. The hydrants are used for tapping waer from mains for
Correct : D. all of these
23. The presence of calcium and magnesium bi-carbonates in water causes hardness in the water.
Correct : A. Correct
24. The acration of water is done to remove
Correct : D. all of these
25. The time of contact for chlorination should be at least
Correct : B. 20 minutes
26. A sewer which receives discharge of a number of house sewers is called a
Correct : C. lateral sewer
27. The artesian spring has too much hydraulic gradient and water flows out automatically.
Correct : A. Right
28. The slow sand filter should be cleaned if the loss of head becomes more than
Correct : B. 1.2 m
29. The self cleaning velocity, recommended for Indian conditions, in order to prevent settling down of seqage at the bottom or on the sides of a large sewer is
Correct : C. 0.75 m/s
30. The ground water is generally free from
Correct : A. suspended
31. The amount of oxygen required for the biological decomposition of dissovled organic solids to occur under aerobic conditions is called bio-chemical oxygen demand (B.O.D.)
Correct : A. Correct
32. Sodium carbonate causes
Correct : B. softness
33. The yield of the well is measured in
Correct : C. either (a) or (b)
34. In the freshly produced sewage, aerobic activity is maximum.
Correct : A. True
35. Turbidity is the measure of resistance to the passage of
Correct : A. light
36. The yield of the well dpends upon the
Correct : D. all of these
37. The layers such as sand and gravel which allow the water to pass through them are known as
Correct : D. all of these
38. The presence of bacteria in water causes
Correct : C. diseases
39. Which of the following statement is correct?
Correct : D. all of the above
40. Alkalinity is caused by positively charged hydrogen ions.
Correct : B. Wrong
41. A drop manhole is provided if
Correct : B. a branch sewer discharges into the main sewer at a higher level
42. A reflux valve, in water distribution system, is used to
Correct : C. prevent water to flow back in the opposite direction
43. For an area developed in haphazard way, the type of layout used for the distribution of pipes is known as
Correct : A. dead end system
44. The apparatus used for feeding chlorine into water is called
Correct : C. chlorinator
45. For the sewers of diameter less than 600 mm, the type of joint preferred is
Correct : A. spigot and socket joint
46. The layers such as lime stone and snd store which do not allow the water to pass through them are known as
Correct : B. aquiclude
47. When lead is present in water, it
Correct : D. none of these
48. For the sewers of diameter more than 600 mm, the type of joint preferred is
Correct : B. collar joint
49. The odour of water does not change with the temperature.
Correct : B. Disagree
50. A sluice valve, in water distribution system, is used to
Correct : B. regulate the flow of water through the pipe
51. Plain chlorination is adopted for treating the water having turbidities less than 20 to 30 ppm.
Correct : A. Correct
52. The formula, F = R - K (1.8 T + 32), for obtaining the annual run-off is known as
Correct : D. Khosla's formula
53. The product of H+ ions and OH- ions in a water solution is equal to
Correct : D. 10?14
54. The water supplysystem should be designed for the present population only.
Correct : B. Disagree
55. Dissolved impurities consist of
Correct : B. iron
56. Water is forced at a preseure higher than the atmospheric pressure in rapid gravity filters.
Correct : B. Wrong
57. Plain sedimentation is a process of retaining water in a basin so that the suspended particles settles down as a result of the
Correct : B. action of gravity and forces
58. The pipe through which liquid waste carrying human excreta flows, is called
Correct : B. soil pipe
59. Which of the following formula is used for computing the quantity of water for fire demand?
Correct : D. all of these
60. The finely divided dispersion of solid particles which are not visible to the naked eye and cannot be removed by ordinary filters are known as
Correct : C. colloidal impurities
61. Rate of filteration of a slow sand filter ranges from
Correct : B. 100 to 200 litres / h / m2
62. For large sewers, the maximum distance between manholes should be
Correct : D. 300 m
63. The velocity of flow in any sedimentation tank should not exceed
Correct : C. 5 mm/s
64. Which of the following statement is correct?
Correct : D. all of the above
65. An arrangement for back washing is provided in
Correct : C. rapid sand filter
66. The seqage is treated by aerobic bacteria action in
Correct : C. oxidation pond
67. Ventilation of house drainage is required to
Correct : D. all of these
68. By base exchange method, water of zero degree hardness can be obtained.
Correct : A. Yes
69. The alkalinity in water is caused by
Correct : D. all of these
70. The quantity of liquid waste which flows in sewers during rainy season is called
Correct : A. storm sewage
71. Cleaning period for a rapid sand filter is taken as
Correct : B. 2 to 3 days
72. The activated sludge
Correct : D. all of these
73. Lead should be present in large quantity in water.
Correct : B. No
74. The water obtained from a lake is known as surface water.
Correct : A. Agree
75. The most commonly used disinfectant for drinking water throughout the world is
Correct : D. chlorine
76. In high rate activated sludge treatment, bacterias are removed from
Correct : D. 80 to 95%
77. The water mains should be designed for
Correct : C. 225%
78. Pressure filters are not used for treating municipal water supplies, because
Correct : D. they are more costly
79. The process of killing pathogenic bacterias from water is called
Correct : D. disinfection
80. Bacterias which cause disease are called
Correct : D. none of these
81. The sewage should be disposed off without causing odour and nuisance.
Correct : A. Right
82. The permanent hardness in water is caused due to the salts like
Correct : D. all of these
83. The sodium carbonate in water
Correct : B. softens the water
84. An artesian spring is formed
Correct : C. when a porous strata gets enclosed between two impervious strata
85. If the size of the sewer is small, then the velocity of flow will be high.
Correct : B. No
86. Slow sand filter is efficient to remove the bacterias from the raw water to an extent of
Correct : D. 99%
87. The bacteria which can survive without oxygen is called
Correct : A. anaerobic bacteria
88. For large cities, the suitable method for forecasting population is
Correct : A. arithmetical increase method
89. When the sewage is to be distributed over a level area surrounded by dykes (i.e. trenches), the mothod of sewage used is called
Correct : A. flooding
90. In order to control the flow of water through pipes, a
Correct : C. gate valve
91. The underground structure in the form of a circular or rectangular tank for the purposes of admitting sewage into it from the intercepting chamber is called a
Correct : B. cess pool
92. A sewer which gets discharge from two or more main sewers is called
Correct : B. trunk sewer
93. Zeolite is
Correct : B. sodium silicate
94. In orthotolodine test, safe residual for drinking water is indicated by
Correct : A. yellow colour
95. The secondary treatment of sewage is carried out by the use of
Correct : C. trickling filters
96. According to Indian standards, 45 litres of water per person per day is provided in case of
Correct : C. offices
97. The plain ends of cast iron pipes are joined by
Correct : D. dresser coupling joint
98. Pressure filters are best suited for
Correct : D. all of these
99. A pressure relief valve is provided to prevent
Correct : C. the increase of pressure after certain safe limit