MCQ
1. The sewage is treated by aerobic bacteria action in -
settling tank
oxidation pond
trickling filter
all of these
2. They - living here since 2000.
are
have been
are still
will be
ব্যাখ্যা: Since + নির্দিষ্ট সময় উল্লেখ থাকায় বাক্যটি Present perfect continuous tense এ হবে। Present perfect continuous tense এর structure হলো Sub + have/has + been + verb + ing + since/for + time। সুতরাং শূন্যস্থানে have been বসবে।
3. Biological action is used in-
screens
trickling filters
sedimentation tank
all of these
4. The anti-siphonage pipe is not required in ---system.
one pipe
single stack
two pipe
none of these
5. The biochemical treatment of sewage effluent is a process of-
oxidation
self-purification
deoxidation
sedimentation
6. A scour value, in a water distribution system, is provided at-
low points
junction points
high points
all of these
7. The equipment used for cleaning the sewers easily is called-
gauge
claw
scoop
scraper
8. In one pipe system of plumbing, waste water is carried away from-
bathrooms
kitchens
wash basins
all of these
9. Pre-chlorination-
reduces odours
reduces tastes
improves coagulation
all of these
10. Air vent pipe is not essentially required in a septic tank-
true
false
11. The process of dechlorination is followed by-
plain
de
post
super
12. In primary settling tank, suspended solids are reduced from-
10 to 20%
20 to 40%
40 to 70%
70 to 90%
13. Grit chambers of a sewage plant are usually changed after-
1 day
2 weeks
1 week
4 weeks
14. The presence of ---causes red colour in water.
iron
sodium fluoride
manganese
calcium carbonate
15. A pipe installed for ventilation purpose is called-
wash pipe
vent pipe
soil pipe
anti-siphonage pipe
16. Aerobic bacteria takes place in the of ---light.
Presence
absence
17. The secondary treatment of sewage is carried out by the use of-
screens
grit chambers
trickling filters
chlorinators
18. In high rate activated sludge treatment, bacteria are removed from-
20 to 40%
40 to 60%
60 to 80%
80 to 95%
19. The effluents from the septic tank are discharged into--
soak pit
drainage
oxidation pond
sewer
20. The sewage is treated by aerobic bacteria action in-
settling tank
trickling filter
oxidation pond
all of these