The width of a rectangular sewer is twice its depth while discharging 1.5 m/sec. The width of the sewer is______________?
(A) 0.68 m
(B) 0.88 m
(C) 1.36 m
(D) 1.76 m
In SI units the power of sound is represented in __________________?
(A) Kgs
(B) Joules
(C) Newtons
(D) Watts
For the survival of fish in a river stream, the minimum dissolved oxygen is prescribed________________?
(A) 3 ppm
(B) 4 ppm
(C) 5 ppm
(D) 10 ppm
The coagulant widely used for sewage treatment, is_________________?
(A) Alum
(B) Ferric chloride
(C) Ferric sulphate
(D) Chlorinated copperas
In a sludge digestion tank if the moisture content of sludge V1 litres is reduced from p1 % to p2 % the volume V2 is____________________?
(A) [(100 + P1)/(100 – P2)] V1
(B) [(100 – P1)/(100 + P2)] V1
(C) [(100 – P1)/(100 – P2)] V1
(D) [(100 + P2)/(100 – P1)] V1
The sewage treatment in septic tanks is due to__________________?
(A) Anaerobic decomposition
(B) Aerobic decomposition
(C) Parasitic decomposition
(D) None of these
If is the rugosity coefficient, is the bed slope of sewer, the velocity of flow in m/sec may be obtained by the formula V = (1/n) r2/3 s1/2 evolved by_________________?
(A) Chezy
(B) Manning
(C) Bazin
(D) Kutter
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______________________?
(A) 100 mg/l
(B) 200 mg/l
(C) 300 mg/l
(D) 400 mg/l
Assertion A.: The minimum self cleansing velocity in the sewer, at least once a day, must be generated. Reason (R): If certain deposition takes place and is not removed, it obstructs free flow and causes further deposition leading to complete blocking of the sewer?
(A) Both A and R are true and R is the correct explanation of A
(B) Both A and R are true but R is not a correct explanation of A
(C) A is true but R is false
(D) A is false but R is true
Dry water flow in a combined sewer, is______________________?
(A) Industrial sewage
(B) Domestic sewage
(C) Storm water
(D) Inclusive of domestic and industrial sewage but excludes storm water