A. 30 to 40%
B. 40 to 60%
C. 60 to 80%
D. 80 to 90%
Related Mcqs:
- In a trickling filter_________________?
A. Filtration process is used
B. Biological action is used
C. Neither A. nor B.
D. Both A. and B. - 15 cumecs, the depth d and width are related by For drains up to___________________?
A. d = 0.2 B
B. d = 0.5 B
C. B = 0.2 d
D. B = 0.5 d - Surface energy per unit area of a surface is numerically equal to___________________?
A. atmospheric pressure
B. surface tension
C. force of adhesion
D. force of cohesion
E. viscosity - The velocity of jet of water travelling out of opening in a tank filled with water is proportional to___________________?
A. head of water (h)
B. h2
C. V/T
D. h2
E. h3/1. - 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 moisture content of sludge is reduced from 90% to 80% in a sludge digestion tank. The percentage decrease in the volume of sludge, is_______________?
A. 25 %
B. 50 %
C. 10 %
D. 5 % - The reduced levels of the string at the consecutive sight rails A and B are 203.575 m, 203.475 m respectively. If the difference of their R.D.s is 10 m, the gradient of the sewer line is_________________?
A. 1 in 100 upward
B. 1 in 500 upward
C. 1 in 100 downward
D. 1 in 503 upward - For a continuous flow type of sedimentation tanks__________________?
A. Width of the tank is normally kept about 6 m
B. Length of the tank is normally kept 4 to 5 times the width
C. Maximum horizontal flow velocity is limited to 0.3 m/minute
D. All the above - Skimming tanks are__________________?
A. Used to remove the grease and oil
B. Those from which sludge is skimmed out
C. Tanks provided with self- cleansing screens
D. Improved version of grit chambers - The ratio of maximum sewage flow to average sewage flow for mains up to 1 m in diameter, is___________________?
A. 1.5
B. 2.0
C. 3.0
D. 4.0
