A. helps growth of bacterias
B. impedes growth of algae
C. increases dissolved oxygen content
D. reduces turbidity
Related Mcqs:
- Disinfection of drinking water, is done to remove_________________?
A. odour
B. bacterias
C. turbidity
D. colour - The yield of a rapid gravity filter as compared to that of slow sand filter, is__________________?
A. 10 times
B. 15 times
C. 20 times
D. 30 times
E. 35 times - For determining the velocity of flow of underground water, the most commonly used non-empirical formula is________________?
A. Darcy’s formula
B. Slichter’s formula
C. Hazen’s formula
D. Lacy’s formula - The maximum depth of sedimentation tanks is limited to________________?
A. 2 m
B. 3 m
C. 4 m
D. 5 m
E. 6 m - Corrosion of well pipes may not be reduced by_________________?
A. reducing the draw down and the pumping rate
B. reducing the flow velocity
C. using thicker pipes
D. using screens having larger area of openings
E. none of these - Surge tanks are used_______________?
A. for storage water
B. to increase the velocity in a pipeline
C. as overflow valves
D. to guard against water hammer - Biochemical Oxygen Demand (B.O.D.) of safe drinking water must be________________?
A. nil
B. 5
C. 10
D. 15
E. 20 - In distribution pipes, drain valves are provided at_______________?
A. lower point
B. higher point
C. junction points
D. any where - The R.L. of ground water table on the sides of a valley is 1505 m whereas R.L. of the stream water is 1475 m. If 60° slope consists of pervious soil between R.L. 1485 m to 1500 m, the gravity spring may be expected at the point of reduced level_______________?
A. 1500 m
B. 1505 m
C. 1475 m
D. 1485 m - Aeration of water is done to remove______________?
A. odour
B. colour
C. bacterias
D. hardness
E. turbidity
