A. 15 cm c/c
B. 22.5 cm c/c
C. 30 cm c/c
D. 50 cm c/c
Related Mcqs:
- The bottom of the sewage inlet chamber of septic tanks, is provided an outward slope_________________?
A. 1 in 5
B. 1 in 10
C. 1 in 15
D. 1 in 20 - To prevent settling down of sewage both at the bottom and on the sides of a large sewer, self-cleaning velocity recommended for Indian conditions, is_________________?
A. 0.50 m/sec
B. 0.60 m/sec
C. 0.70 m/sec
D. 0.75 m/sec - The pressure exerted by_____________?
A. The sewage when running full from inside, is called internal pressure
B. The internal pressure if any, causes tensile stress in the pipe material
C. Pressure sewers are designed to be safe in tension
D. All the above - Hume steel pipes are__________________?
A. Steel pipes
B. Steel shell coated from inside with cement mortar
C. Steel shell coated from outside with cement mortar
D. Both B. and C. - Chlorination of water is done for the removal of____________________?
A. Bacterias
B. Suspended solids
C. Sediments
D. Hardness - Facultative bacteria survive in_____________________?
A. The presence of oxygen
B. The absence of oxygen
C. Both cases A. and B.
D. Neither A. nor B. - The presence of free ammonia in sewage, is detected by___________________?
A. Boiling
B. Adding potassium permanganate
C. Adding sulphuric acid
D. Phenol-di-sulphuric acid - 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 - If D.O. concentration falls down to zero in any natural drainage, it indicates the zone of__________________?
A. Degradation
B. Active decomposition
C. Recovery
D. Cleaner water - pH value of sludge during alkaline regression stage, is__________________?
A. More than 7
B. Less than 7
C. Less than 6
D. More than 6
