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

Related Mcqs:

1. The specific retention is least in case of_______________?

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

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

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

3. 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

4. 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

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

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

6. 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

7. 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

8. Biochemical Oxygen Demand (B.O.D.) of safe drinking water must be________________?

   A. nil
   B. 5
   C. 10
   D. 15
   E. 20

9. 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

10. Aeration of water is done to remove______________?

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