MCQ
17821. The minimum size of a fire hydrant is--
5cm
10cm
15cm
20cm
17822. Air vent pipe is not essentially required in a septic tank-
true
false
17823. The cross-section recommended for separate system of sewerage is--
circular
rectangular
egg-shaped
none of these
17824. Grit chambers of a sewage plant are usually changed after-
1 day
2 weeks
1 week
4 weeks
17825. The equipment used for cleaning the sewers easily is called-
gauge
claw
scoop
scraper
17826. A pipe installed for ventilation purpose is called-
wash pipe
vent pipe
soil pipe
anti-siphonage pipe
17827. The minimum diameter of a manhole cover should be-
25cm
50cm
75cm
100cm
17828. In primary settling tank, suspended solids are reduced from-
10 to 20%
20 to 40%
40 to 70%
70 to 90%
17829. The secondary treatment of sewage is carried out by the use of-
screens
grit chambers
trickling filters
chlorinators
17830. Biological action is used in-
screens
trickling filters
sedimentation tank
all of these
17831. The sewage is treated by aerobic bacteria action in-
settling tank
trickling filter
oxidation pond
all of these
17832. In high rate activated sludge treatment, bacteria are removed from-
20 to 40%
40 to 60%
60 to 80%
80 to 95%
17833. The biochemical treatment of sewage effluent is a process of-
oxidation
self-purification
deoxidation
sedimentation
17834. In one pipe system of plumbing, waste water is carried away from-
bathrooms
kitchens
wash basins
all of these
17835. The water from kitchens, bathrooms, wash basins is called-
sewage
raw sewage
sullage
none of this
17836. The effluents from the septic tank are discharged into--
soak pit
drainage
oxidation pond
sewer
17837. The human excreta is a ---waste.
dry
liquid
semi-liquid
solid
17838. The internal diameter of the sewer should not be less than-
15cm
25cm
50cm
75cm
17839. Aerobic bacteria takes place in the of ---light.
Presence
absence
17840. The sewage is treated by aerobic bacteria action in -
settling tank
oxidation pond
trickling filter
all of these