Drop manholes at the junctions of sewer lines, are provided if________________?
(A) Invert level of a branch sewer is more than 60 cm that of the main sewer
(B) Sewer line runs along a main road
(C) Ordinary manhole cannot be built
(D) Two sewer lines intersect
During purification process of sewage the gas given off, is________________?
(A) Carbon dioxide
(B) Hydrogen
(C) Ammonia
(D) All the above
The sewerage system originates from__________________?
(A) House sewers
(B) Lateral sewers
(C) Branch sewers
(D) Main sewers
In septic tanks, decomposition of organic bacteria, is done by_____________________?
(A) Anaerobic bacteria
(B) Aerobic bacteria
(C) Both types of bacterias
(D) None of these
The sewage is pumped up_______________?
(A) From low lying areas
(B) From flat areas
(C) From basements
(D) All the above
Which one of the following tests is used for testing sewer pipes ?
(A) Water test
(B) Ball test
(C) Mirror test
(D) All of these
The non-clog pump which permits solid matter to pass out with the liquid sewage, is________________?
(A) Centrifugal pump
(B) Reciprocating pump
(C) Pneumatic ejector
(D) None of these
When drainage to sewage ratio is 20, the peak dry weather flow is_______________?
(A) 20% of the design discharge
(B) Slightly less than 5% of the design discharge
(C) Slightly more than 5% of the design discharge
(D) None of these
Flocculated particles do not change their___________________?
(A) Size
(B) Shape
(C) Weight
(D) None of these
For providing an Indian type W.C., the R.C.C. slabs in the toilet portion__________________?
(A) Should be sunk by 20 cm
(B) Should be kept 20 cm above the adjacent portion
(C) Should be sunk by 50 cm
(D) Need not be sunk