Imhoff cone is used to determine_____________________?
(A) Settleable solids
(B) Suspended solids
(C) Dissolved solids
(D) None of these
As compared to fresh river water, sea water contains oxygen_________________?
(A) 10% less
(B) 20% less
(C) 10% more
(D) 20% more
With self cleansing velocity in sewers___________________?
(A) Silting occurs at bottom
(B) Scouring occurs at bottom
(C) Both silting and scouring occur at bottom
(D) Neither silting nor scouring occurs at bottom
If the grit in grit chambers is 4.5 million litres per day, its cleaning is done____________________?
(A) Manually
(B) Mechanically
(C) Hydraulically
(D) Electrically
The angle subtended by the surface of sewer water with partial flow, at sewer centre is 120°, the depth of sewerage is________________________?
(A) 20 cm
(B) 25 cm
(C) 40 cm
(D) 50 cm
The gas evolved in sewers is________________?
(A) Carbondioxide
(B) Hydrogen sulphide
(C) Methane
(D) All of these
In sewage, the solids in mg per litre is__________________?
(A) 100 to 500
(B) 500 to 1000
(C) 1000 to 1500
(D) 1500 to 2000
If is the diameter of upper circular portion, the area of cross-section of a standard egg shaped sewer, is____________________?
(A) D²
(B) D²
(C) D²
(D) D²
The small sewers are cleaned by____________________?
(A) Flushing
(B) Cane rodding
(C) Wooden pills
(D) None of these