The self-cleansing velocity of water flowing through pipe lines, is___________________ ?

Related Mcqs:

1. If the diameter of sewer is 225 mm, the gradient required for generating self cleansing velocity, is___________________?

   A. 1 in 60
   B. 1 in 100
   C. 1 in 120
   D. None of these

2. Self-cleansing velocity is__________________?

   A. Velocity at dry weather flow
   B. Velocity of water at flushing
   C. Velocity at which no accumulation remains in the drains
   D. Velocity of water in a pressure filter

3. With self cleansing velocity in sewers___________________?

   A. Silting occurs at bottom
   B. Scouring occurs at bottom
   C. Both silting and scouring occur at bottom
   D. Neither silting nor scouring occurs at bottom

4. If the diameter of a sewer is 100 mm, the gradient required for generating self cleansing velocity is__________________?

   A. 1 in 60
   B. 1 in 100
   C. 1 in 120
   D. None of these

5. Assertion A.: The minimum self cleansing velocity in the sewer, at least once a day, must be generated. Reason (R): If certain deposition takes place and is not removed, it obstructs free flow and causes further deposition leading to complete blocking of the sewer?

   A. Both A and R are true and R is the correct explanation of A
   B. Both A and R are true but R is not a correct explanation of A
   C. A is true but R is false
   D. A is false but R is true

6. If the diameter of a sewer is 150 mm, the gradient required for generating self cleansing velocity, is________________?

   A. 1 in 60
   B. 1 in 100
   C. 1 in 120
   D. None of these

7. In sewers designed with self cleansing velocity________________?

   A. The bottom is silted
   B. The bottom is scoured
   C. Both silting and scouring occur at the bottom
   D. Neither silting nor scouring occurs at the bottom

8. At the centre line of a pipe flowing under pressure where the velocity gradient is zero, the shear stress will be_______________?

   A. minimum
   B. maximum
   C. zero
   D. negative value
   E. could be any value

9. weight of water, the hydraulic mean depth of the sewer and the bed slope w is the unit of the sewer, then the tractive force exerted by flowing water, is________________________?

   A. w r S S
   B. w r1/2
   C. w r S
   D. w r2/3

10. A sewer pipe contains 1 mm sand particles of specific gravity 2.65 and 5 mm organic particles of specific gravity 1.2, the minimum velocity required for removing the sewerage, is_____________________?

    A. 0.30 m/sec
    B. 0.35 m/sec
    C. 0.40 m/sec
    D. 0.45 m/sec