MCQ
1. In primary settling tank, suspended solids are reduced from-
10 to 20%
20 to 40%
40 to 70%
70 to 90%
2. Biological action is used in-
screens
trickling filters
sedimentation tank
all of these
3. The effluents from the septic tank are discharged into--
soak pit
drainage
oxidation pond
sewer
4. Pre-chlorination-
reduces odours
reduces tastes
improves coagulation
all of these
5. The process of dechlorination is followed by-
plain
de
post
super
6. The biochemical treatment of sewage effluent is a process of-
oxidation
self-purification
deoxidation
sedimentation
7. The secondary treatment of sewage is carried out by the use of-
screens
grit chambers
trickling filters
chlorinators
8. The sewage is treated by aerobic bacteria action in-
settling tank
trickling filter
oxidation pond
all of these
9. A pipe installed for ventilation purpose is called-
wash pipe
vent pipe
soil pipe
anti-siphonage pipe
10. The sewage is treated by aerobic bacteria action in -
settling tank
oxidation pond
trickling filter
all of these
11. Aerobic bacteria takes place in the of ---light.
Presence
absence
12. Air vent pipe is not essentially required in a septic tank-
true
false
13. The equipment used for cleaning the sewers easily is called-
gauge
claw
scoop
scraper
14. The minimum diameter of a manhole cover should be-
25cm
50cm
75cm
100cm
15. A scour value, in a water distribution system, is provided at-
low points
junction points
high points
all of these
16. The anti-siphonage pipe is not required in ---system.
one pipe
single stack
two pipe
none of these
17. In high rate activated sludge treatment, bacteria are removed from-
20 to 40%
40 to 60%
60 to 80%
80 to 95%
18. The presence of ---causes red colour in water.
iron
sodium fluoride
manganese
calcium carbonate
19. Grit chambers of a sewage plant are usually changed after-
1 day
2 weeks
1 week
4 weeks
20. In one pipe system of plumbing, waste water is carried away from-
bathrooms
kitchens
wash basins
all of these