A. Are water seals which prevent the entry of foul gases
B. Are used to trap the rats entering sewers
C. Dissolve the foul gases
D. Create symphonic action to increase the quick disposal of sewerage
Related Mcqs:
- 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 - For treating the sewage of a large city, you will recommend_________________?
A. A sedimentation tank and an activated sludge treatment plant
B. A plant consisting of Imhoff tanks with low rate trickling filters
C. Sedimentation tanks with high rate trickling filters
D. None of these - The settling velocity of a spherical particle of diameter less than 0.1 mm as per Stock’s law, is__________________?
A. Vs = 418 (Gs – Gw) d [(3T + 70)/100]
B. Vs = 418 (Gs – Gw)d² [(3T + 70)/100]
C. Vs = 218 (Gs – Gw)d² [(3T + 70)/100]
D. Vs = 218 (Gs – Gw)d [(3T + 70)/100] - In detritus tanks______________________?
A. Flow velocity is kept 0.09 m/sec
B. Detention period is kept 3 to 4 minutes
C. Organic and inorganic materials are separated
D. All the above - A rainfall may be classified as acidic if its pH value is less or equal to________________?
A. 6
B. 7
C. 5
D. 6.5 - 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 following is the physical characteristic of sewage___________________?
A. Turbidity
B. Colour
C. Odour
D. All the above - The minimum diameter of a sewer is kept __________________?
A. 10 cm
B. 15 cm
C. 20 cm
D. 25 cm - Pick up the in-correct statement from the following?
A. Manholes are provided in sewer pipes at suitable intervals
B. Catch basins are generally provided in sewers for carrying drainage discharge
C. Inlets are generally provided in all sewers
D. None of these - For a grit chamber, if the recommended velocity of flow is 0.2 m/sec and detention period is 2 minutes, the length of the tank, is__________________?
A. 16 m
B. 20 m
C. 24 m
D. 30 m
