MCQ
61. The water obtained from is generally known as sub-surface water---
rain
reservoirs
rivers
artesian wells
62. Absolute zero temperature = ?
0°C
273°C
-273°C
None
63. The water obtained from a lake is known as surface water.
Agree
Disagree
64. Main element of biogas is
CO2
Cow dung
Water
CH4
65. Absolute pure water is good for health.
right
wrong
66. The maximum permissible limit for iron in drinking water is-
0.1 mg/L
0.3-1 mg/L
2-2.5 mg/L
5 mg/L
67. Disinfection of water results in-
Removal of turbidity
Removal of taste
Killing of disease bacteria
Removal of hardness
68. The diameter of a domestic sewer pipe laid at gradient 1 in 100 is recommended ------
100 mm
200mm
150mm
175mm
69. Standard BOD is measured at-
20°C-1 day
25°C-3 day
20°C-5 day
30°C-5 day
70. What do you mean by BOD?
Best organized demand
Biochemical oxygen demand
Before oxidation damage
Bacteria of damage
71. Which of the following protects penstock due to sudden variation of flow or velocity of water?
Anchors
Trash rack
Forebays
Surge tank
72. What is the example of metamorphic rock?
granite
genesis
marble
all of these
73. The presence of sodium chloride in water-
stops epidemic
increases hardness of water
causes bad taste
softens the water
74. The maximum permissible quantity of lead in water for domestic supplies is-
0.01 ppm
0.05 ppm
0.50 ppm
1 ppm
75. A manhole is generally provided at each-
bend
change of gradient
junction
all the above
76. Slow sand filter is efficient to remove the bacteria from the raw water to an extent of-
50%
70%
85%
99%
77. The quality of tube well water is ---as compaired to surface water
good
poor
78. A pipe conveying sewage from plumbing system of a single building to common sewer is called-
house sewer
lateral sewer
main sewer
submain sewer
79. Arsenic contamination has primarily affected-
the deep aquifer
the river
the shallow aquifer
none
80. The term sullage refers to-
fresh waste water
waste water from kitchen and laundry
septic waste water
toxic waste water