Q.1
Flocculated particles do not change their
Q.2
The dimensions of a rectangular settling tank are: length 24 m, width 6 m and depth 3 m. If 2 hour detention period for tanks is recommended, the rate of flow of sewage per hour, is
Q.3
Bottom openings 15 cm × 15 cm in the standing baffle wall are provided
Q.4
If the grit in grit chambers is 4.5 million litres per day, its cleaning is done
Q.5
In R.C. sewer pipes, the percentage longitudinal reinforcement to the cross-sectional area of concrete is kept
Q.6
The most dangerous pollutant in vehicular emissions is
Q.7
The moisture content of sludge is reduced from 90% to 80% in a sludge digestion tank. The percentage decrease in the volume of sludge, is
Q.8
The effluent of a septic tank is
Q.9
5 days-biochemical oxygen demand (BOD5) is taken at a temperature of
Q.10
Imhoff cone is used to determine
Q.11
The algae dies out in the zone of
Q.12
For detecting the nitrates in sewage, the colour may be developed by adding
Q.13
Ventilating shafts are provided to a sewer line at every
Q.14
A manhole is classified as shallow if its depth is between
Q.15
The design period in years for pumping plants, is
Q.16
At the junction of sewers
Q.17
The most effective arrangement for diverting excess storm water into a natural drainage, is
Q.18
The bottom of the sewage inlet chamber of septic tanks, is provided an outward slope
Q.19
Drop manholes are the manholes
Q.20
For laying a sewer line in a trench of 2 m width, an offset line is marked on the ground parallel to the given centre line at a distance of
Q.21
For detecting the nitrites in the sewage, the matching colour may be developed by adding
Q.22
The average temperature of sewage in India, is
Q.23
In a fully mechanised composting plant, involves
Q.24
For drainage pipes in buildings the test applied before putting them to use, is
Q.25
During purification process of sewage the gas given off, is
Q.26
Which of the following pumps in used to pump sewage solids with liquid sewage without clogging the pump is?
Q.27
The width of a rectangular sewer is twice its depth while discharging 1.5 m/sec. The width of the sewer is
Q.28
The water carried sewerage system removes
Q.29
For the survival of fish in a river stream, the minimum dissolved oxygen is prescribed
Q.30
Antisyphonage pipe is fitted
Q.31
The detention time of a circular tank of diameter d and water depth H, for receiving the sewage Q per hour, is
Q.32
For a grit chamber, if the recommended velocity of flow is 0.2 m/sec and detention period is 2 minutes, the length of the tank, is
Q.33
If is the diameter of upper circular portion, the overall depth of a standard egg shaped section, is
Q.34
For a peak discharge of 0.0157 cumec, with a velocity of 0.9 m/sec, the diameter of the sewer main, is
Q.35
3.0 ml of raw sewage is diluted to 300 ml. The D.O. concentration of the diluted sample at the beginning of the test was 8 mg/l. After 5 day-incubation at 20°C, the D.O. concentration was 5 mg/l. The BOD of raw sewerage is
Q.36
1000 kg of sewage contains
Q.37
Pick up the incorrect statement from the following:
Q.38
Pick up the correct statement from the following:
Q.39
The most efficient cross section of sewers in a separate sewerage system is
Q.40
Rate of flow of sewage is generally assumed
Q.41
House connections to the laterals is generally made by
Q.42
The self-cleansing velocity of water flowing through pipe lines, is
Q.43
If a paper moistened with lead acetate for five minutes when placed in manhole turns black. The sewer certainly contains
Q.44
If the flame of a miner’s safety lamp in a manhole extinguishes within 5 minutes, the sewer certainly contains
Q.45
Sewer pipes need be checked for
Q.46
In the activated sludge process
Q.47
Water content of sewage is about
Q.48
A circular sewer section is preferred to because
Q.49
The most efficient cross-section of sewers in a combined sewerage system is
Q.50
The minimum diameter of a sewer is kept
0 h : 0 m : 1 s