Water Supply & Sanitation Engineering Online Test – Paper 3

1. The bacteria which require free oxygen for their survival are called:

2. Poppet valve is a type of

3. According to the guidelines of DWSS, the maximum number of users in each stand post should be:

4. The water carriage sewage system:

5. To determine the velocity of the flow of underground water, the most commonly used non-empirical formula is....formula:

6. Disinfection of water involves.....

7. The factor to be considered for the source of water supply is:

8. The head developed in a centrifugal pump, at zero discharge is known as

9. The alum, when mixed with water as a coagulant...... PH value of water.

10. Sanitary sewage means:

11. The sewer meant to carry excess discharge from an existing sewer is called:

12. The most dangerous metal for human health is

13. Copper pipes are

14. For separate and partially separate systems, the pattern of collection suitable is:

15. Air inlet valve is provided in water mains at

16. The maximum amount of copper in domestic water should be

17. Before entering a manhole, a candle is lowered into the manhole:

18. Which one is correct?

19. The slope of the hydraulic grade line is always towards the well due to pumping. This line of depressed water table is called

20. A sewer, which gets its flow from a number of transverse sewers, is known as:

21. The relation between porosity, specific yield, and specific retention is given by

22. For a 150mm diameter sewer, the gradient required to generate self-cleaning velocity is:

23. Water of zero hardness is obtained by

24. The gradient to be provided for sewers depends upon:

25. The flow in the sewers is minimum during which hours?

26. The water supply system whose main, sub-main, and branches are interconnected with each other is:

27. A 1 m cast iron pipe carries a discharge of 0.785 cum/sec, the velocity of flow will be

28. The aquifer having the least water-bearing capacity is

29. Pressure relief valve is provided in the water main

30. Turbidity of water is measured in

31. The factor for the selection of the pumping station site is

32. If 10 ml of raw sewage is diluted to 250 ml, and the dissolved oxygen content of the diluted sample changes from 9 mg/l to 5 mg/l after incubation at 20°C. for 5 days, BODs of raw sewage is:

33. Mass action' during sedimentation is the property of:

34. A G.I. pipe has a coating of

35. Which traps have parallel legs?

36. The ratio of the maximum daily consumption to the average demand is

37. Two sewer sections laid at the same grade will be hydraulically equivalent if:

38. Inverted siphon is made of:

39. A goose neck is:

40. Thrust blocks are installed wherever there is a

41. If the diameter of a sewer is 150 mm, the gradient required for generating a self-cleaning velocity is:

42. In the two-pipe system of plumbing, the number of vertical pipes is:

43. When the limiting non-scouring velocity is 5 m/sec, the type of sewer generally used is:

44. Sewer which gets discharge from two or more main sewers is called:

45. Depth of shallow tube well shall not be more than (considering economic point):

46. Excess concentration of sodium salts in water causes

47. Where it is not possible to obtain self-cleansing velocities for sewers, flush are provided with the minimum available head of:

48. The hourly variation factor is generally taken

49. Gravity conduits are generally in the form of

50. Sluice valves in main water supplies are