In sewage having fully oxidised organic matter, the nitrogen exists in the form of________________?
(A) Nitrites
(B) Nitrates
(C) Free ammonia
(D) Aluminoid nitrogen
Clogging of sewers, is caused due to_______________?
(A) Silting
(B) Low discharge
(C) Greasy and oily matters
(D) All the above
The sewer pipe which carries sewage from a building for immediate disposal is______________?
(A) House sewer
(B) Lateral sewer
(C) Intercepting sewer
(D) Main sewer
If the diameter of sewer is 225 mm, the gradient required for generating self cleansing velocity, is___________________?
(A) 1 in 60
(B) 1 in 100
(C) 1 in 120
(D) None of these
The following is the physical characteristic of sewage___________________?
(A) Turbidity
(B) Colour
(C) Odour
(D) All the above
Fresh sewage is generally_____________________?
(A) Alkaline
(B) Acidic
(C) Highly decomposed
(D) A source of objectionable odour
It is customary to design a sewer for D.W.F. on the basis of________________?
(A) Average demand
(B) Twice the average demand
(C) Thrice the average demand
(D) Four times the average demand
For detecting the nitrites in the sewage, the matching colour may be developed by adding_________________?
(A) Potassium permanganate
(B) Sulphuric acid and napthamine
(C) Phenol-di -sulphuric acid potassium hydroxide
(D) None of these
The laying of sewers is done with____________________?
(A) Magnetic compass
(B) Theodolite
(C) Level
(D) Clinometer
The settlement velocity of a solid (diameter 0.5 mm, specific gravity 1.75) in water having temperature 10°C, is______________________?
(A) 213.5 cm/sec
(B) 313.5 cm/sec
(C) 413.5 cm/sec
(D) 500 cm/sec