51
A rain sanitary sewer is constructed to carry
A)
Sanitary sewage
B)
Storm sewage
C)
Surface water
D)
Ground water
Answer & Solution
Answer: Option
B
52
Primary treatment of sewage consists of removal of
A)
Large suspended organic solids
B)
Oil and grease
C)
Sand and girt
D)
Floating materials
Answer & Solution
Answer: Option
A
53
For efficient working of a sewer, it must be ensured that
A)
Minimum velocity of 0.45 m/sec, is maintained at its minimum flow
B)
A maximum velocity of 0.90 m/sec, is maintained at its maximum flow
C)
Both (A) and (B)
D)
Neither (A) nor (B)
Answer & Solution
Answer: Option
C
54
In olden days the type of section adopted in trunk and out fall sewers was
A)
Parabolic shaped
B)
Horse shoe shaped
C)
Egg shaped
D)
Circular shaped
Answer & Solution
Answer: Option
B
55
The sewer which collects the discharge from a collecting system and delivers it to a treatment plant, is known
A)
House sewer
B)
Lateral sewer
C)
Branch sewer
D)
Sewer outfall
Answer & Solution
Answer: Option
D
56
Lead acetate test in sewer manhole is done to test the presence of
A)
Methane gas
B)
Hydrogen sulphide
C)
Carbondioxide gas
D)
Diesel vapours
Answer & Solution
Answer: Option
B
57
The sewers . . . . . . . .
A)
Must be of adequate size to avoid over flow
B)
Must flow under gravity $$\frac{1}{2}$$ to $$\frac{3}{4}$$ full
C)
Must be laid at least 2 to 3 m deep to collect /water from the basements
D)
All the above
Answer & Solution
Answer: Option
D
58
The normal values of over flow rates for sedimentation tanks using coagulant, ranges between
A)
25,000 to 35,000 litres/sqm/day
B)
40,000 to 50,000 litres/sqm/day
C)
50,000 to 60,000 litres/sqm/day
D)
80,000 to 100,000 litres/sqm/day
Answer & Solution
Answer: Option
C
59
The detention period for plain sedimentation water tanks, is usually
A)
4 to 8 hours
B)
8 to 16 hours
C)
16 to 24 hours
D)
24 to 36 hours
Answer & Solution
Answer: Option
A
60
The minimum recommended diameter of sewers, is
A)
5 cm
B)
10 cm
C)
15 cm
D)
20 cm
Answer & Solution
Answer: Option
C
