2. The total count of bacteria per cubic centimetre for domestic purposes varies from
Correct : A. 0 to 100
3. The internal diameter of the sewer should not be less than
Correct : A. 15 cm
4. The minimum dissolved oxygen required in water to save the aquatic life is
Correct : C. 4 ppm
5. Which of the following statement is wrong?
Correct : D. none of the above
6. B-coli or E-coli are harmless organisms but their presence in water indicates the
Correct : A. presence of pathogenic bacteria
7. In combined system, automatic flushing is not possible.
Correct : B. Incorrect
8. The copper contents in water for domestic purposes should not be
Correct : B. more than
9. The maximum permissible quantity of iron and manganese in water for domestic purposes should be
Correct : B. 0.3 ppm
10. The maximum permissible fluorine content in water for domestic supplies should be
Correct : B. 1.5 ppm
11. When high level spots are not available for the construction of ground level reservoirs, elevated reservoirs can be used.
Correct : A. Agree
12. The capacity of the pumps is normally expressed as
Correct : D. all of these
13. In presure filters, water is forced at a pressure
Correct : C. greater than
14. No deposition will take place in
Correct : B. smaller
15. The volume of a settling basin is large due to
Correct : D. none of the above
16. The main object of sewage disposal is
Correct : D. all of the above
17. For building drainage pipes, a smoke test is applied.
Correct : A. Correct
18. The maximum permissible colour for domestic supplies, on platinum cobalt scale is
Correct : B. 10 to 20 ppm
19. The maximum permissible turbidity for domestic supplies, on silica scale is
Correct : A. 5 to 10 ppm
20. The rate of settling of a particle in water depends upon the
Correct : D. all of these
21. The quantity of water available from an infiltration gallery depends upon the
Correct : D. all of these
22. The treatment which employs mechanical and hydraulic separation principles is referred as secondary treatment.
Correct : B. No
23. A good trap should
Correct : C. provide an adequate water seal at all times
24. The organic impurities in water form a layer on the top of a filtering media. Such a layer is called
Correct : C. dirty skin
25. In one pipe system of plumbing, waste water is carried away from
Correct : D. all of these
26. In designing a water works for a city to meet the water demand for public use, a provision of about
Correct : B. 10%
27. A pipe used to carry discharge from sanitary fittings like bathrooms, kitchens etc, is called
Correct : A. waste pipe
28. When the pH value of water is
Correct : B. less than 7
29. The equipment used for checking the levels of the sewer inverts is
Correct : C. boning rod
30. The pH value of water for public supplies is limited from
Correct : B. 6.5 to 8
31. The yield of a underground source may be obtained by
Correct : C. both (a) and (b)
32. The coefficient of uniformity for rapid sand filters is
Correct : B. less
33. For house drainage and lateral connections, we shall use
Correct : A. stone ware sewers
34. The cross-section recommended for separate system of sewerage is
Correct : C. rectangular
35. In the design of a sedimentation tank, the essential factor to be considered is
Correct : D. all of these
36. House plumbing is difficult in
Correct : A. separate
37. pH value is a symbol for
Correct : B. hydrogen
38. The quantity of arsenic in water for domestic purposes should not be more than 0.05 ppm.
Correct : A. True
39. After cleaning the slow sand filter, the filtered water should not be used for a period of
Correct : D. 24 hours to 48 hours
40. By lime soda process, hardness can be reduced to less than
Correct : A. 50 ppm
41. In pre-chlorination, the raw water is treated with chlorine only.
Correct : B. Disagree
42. Aluminium sulphate may be used for coagulation.
Correct : A. Correct
43. Disposal by dilution will be suitable where
Correct : D. all of the above
44. Cleaning period for a slow sand filter is taken as
Correct : D. 1 month to 3 months
45. The open wells or dug wells wells
Correct : D. all of these
46. In Zeolite process
Correct : D. all of tha above
47. Hard water may cause bursting of boilers.
Correct : A. Agree
48. The amount of water collected in a reservoir is divided into three portions and the order of their existance from bottom to the top is
Correct : C. dead storage, useful storage, surcharge storage
49. The permanent hardness of water can be removed by
Correct : D. zeolite process
50. Coagulation is required when the particles are of
Correct : A. fine
51. A sewer which receives sewage from the collection system and conducts it to a point of final disposal is called a
Correct : D. outfall sewer
52. The effective size of sand particles for rapid sand filters varies from
Correct : B. 0.35 to 0.50 mm
53. Which of the following statement is correct?
Correct : C. Primary clarifiers are to the sedimentation tanks located just after the girt chambers.
54. In India, as per Indian standards, water consumption per capita per day for domestic purpose is
Correct : D. 135 litres
55. Bacteria which can survive with or without free oxygen is known as facultative bacteria.
Correct : A. Correct
56. The minimum size of a fire hydrant is
Correct : C. 15 cm
57. The treatment of water with only chlorine is known as
Correct : A. plain chlorination
58. The under drainage system in a rapid sand filters
Correct : C. both (a) and (b)
59. The under drainage system in slow sand filters
Correct : A. receives and collects the filtered water
60. The storm sewers are essentially required to
Correct : D. all of the above
61. In a rapid sand filter
Correct : C. raw water passed through coagulation tank is supplied
62. In primary settling tank, suspended solids are reduced from
Correct : C. 40 to 70%
63. The domestic use of water amounts to
Correct : D. 50%
64. A combined system will be favourable when
Correct : D. the locality to be served has narrow streets
65. The presence of carbon dioxide in water causes acidity.
Correct : A. True
66. The maximum permissible temperature for domestic supply is
Correct : B. 10 to 15?C
67. Which of the following is not a coagulating agent?
Correct : D. Copper sulphate
68. The bio-chemical treatment of sewage effluent is a process of
Correct : A. oxidation
69. The design period for a water supply project is taken as
Correct : D. 20 to 30 years
70. Which of the following statement is correct?
Correct : A. Pre-chlorination reduces the bacterial load on filters.
71. The bacterias which do not cause any disease are called pathogenic bacterias.
Correct : B. Wrong
72. In order to prevent water to flow back in opposite direction, we shall use a
Correct : D. reflux valve
73. A reflux valve is also known as
Correct : D. check valve
74. The effluents from the septic tank are discharged into
Correct : A. soak pit
75. Which of the following statement is wrong?
Correct : D. The water closet is provided for receiving garbage.
76. Zeolite process is also known as
Correct : C. both (a) and (b)
77. The privy pit should be located at least
Correct : A. 3 m
78. The most common coagulant is
Correct : B. alum
79. A pipe conveying sewage from the plumbing system of a singe building to a common sewer or to the point of immediate disposal is called
Correct : B. house sewer
80. The process of adding certain chemicals to water in order to form flocculent precipitate for absorbing and entraining colloidal mater is called sedimentation with coagulation.
Correct : A. Agree
81. The particle will settle down more rapidly in water at high temperatures than at lower temperatures.
Correct : A. True
82. For a well planned city, we whall use the grid iron system for the distribution of pipes.
Correct : A. Right
83. Which of the following statement is wrong?
Correct : C. Scour valves are provided at high points
84. In a plain sedimentation tank, under normal conditions, impurities are removed upto
Correct : C. 70%
85. The colour of water is expressed in numbers of a
Correct : B. platinum cobalt scale
86. Cess pool is not recommended by the health authorities.
Correct : A. Agree
87. The percentage of chlorine in fresh bleaching powder is
Correct : C. 30 to 35%
88. The amount of chlorine used for plain chlorination of water is about
Correct : D. 0.5 ppm
89. The maximum acidity in water will occur at a pH value of
Correct : A. 0
90. The corrosion in pipe is due to
Correct : D. all of the above
91. The method in which different types of refuse are collected, carried and disposed off separately is called
Correct : D. either (a) and (b)
92. Membrane filter technique is used for testing
Correct : A. E-coli
93. The commercial osmoscope is graduated with pO values from
Correct : A. 0 to 5
94. The sanitation system in which a small portion of storm water is allowed to enter in the sanitary sewage sewers and the remaining storm water flows in separate set of sewers, is known as
Correct : C. partially separate system
95. The effective size of sand particles for slow sand filters varies from
Correct : A. 0.30 to 0.35 mm
96. The process of purifying water by passing it through a bed of fine granular material, is called
Correct : B. filteration
97. In one pipe system of plumbing,
Correct : D. all of the above
98. The water of a river has an important property called