The yield of a rapid gravity filter as compared to that of slow sand filter, is__________________?

Related Mcqs:

1. In slow sland filters, the turbidity of raw water can be removed only up to_________________?

   A. 60 mg/litre
   B. 75 mg/litre
   C. 100 gm/litre
   D. 150 mg/litre

2. The expected discharge to be obtained from an open well sunk in coarse sand is 0.0059 cumec. If the working depression head of the well is 3 m, the minimum diameter of the well, is________________?

   A. 2 m
   B. 2.25 m
   C. 2.50 m
   D. 2.75 m
   E. 3.00 m

3. 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

4. Disinfection of drinking water, is done to remove_________________?

   A. odour
   B. bacterias
   C. turbidity
   D. colour

5. The specific retention is least in case of_______________?

   A. Clay
   B. Sand
   C. Silt
   D. Coarse gravel

6. 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

7. The maximum depth of sedimentation tanks is limited to________________?

   A. 2 m
   B. 3 m
   C. 4 m
   D. 5 m
   E. 6 m

8. Average annual rainfall at any station is the average of annual rainfall over a period of________________?

   A. 7 years
   B. 14 years
   C. 21 years
   D. 28 years
   E. 35 years

9. 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

10. The least thickness of class B cast iron (spun) pipe, is_________________?

    A. 7.2 mm
    B. 7.9 mm
    C. 8.6 mm
    D. 10 mm