Water Supply Civil Engineering Free Online Test - Set 11 - ObjectiveBooks

# Practice Test: Question Set - 11

1. The bacterias which may survive with or without free oxygen, are called
(A) Aerobic bacterias
(B) Anaerobic bacterias
(C) Facultative bacteria's
(D) None of these

2. Aeration of water is done to remove
(A) Odour
(B) Color
(C) Bacterias
(D) Turbidity

3. The maximum pressure to which cast iron pipes may be subjected to, is
(A) 3 kg/cm2
(B) 5 kg/cm2
(C) 7 kg/cm2
(D) 10 kg/cm2

4. Water may not contain much impurity if its source is
(A) Reservoirs
(B) Stream flowing in plains
(C) Lakes in lower regions
(D) Spring along hill slopes

5. If p is total internal pressure, d is diameter of pressure conduit and t is thickness of conduit, the Hoop's stress is
(A) Ï€dp/t
(B) Ï€dp/2t
(C) dp/2t
(D) dt/2p

6. Turbidity of water is expressed
(A) In ppm
(B) In numbers in an arbitrary scale
(C) By pH value
(D) By color code

7. In plain sedimentation tanks under normal conditions, impurities are removed up to
(A) 60 %
(B) 70 %
(C) 80 %
(D) 90 %

8. The equation 0.368 [p/(1.87 + 32)] × (H/√A)0.155 in which Q is yearly run off in cm, P is yearly total rainfall in cm, H is difference of R.L.s. of lowest and highest points and A is area of catchment in square meters, is known as
(A) English formula
(B) Khosla's formula
(C) Justin's formula
(D) Vermule's formula

9. In slow sand filters, the turbidity of raw water can be removed only up to
(A) 60 mg/liter
(B) 75 mg/liter
(C) 100 gm/liter
(D) 150 mg/liter

10. Pressure relief valves are provided in water mains
(A) To reduce the pressure
(B) At low points
(C) Upstream of sluice
(D) All the above

11. Quality of water is said to be good if it is
(A) Free from suspended matter
(B) Colorless
(C) Free from pathogenic organism
(D) All the above

12. Sluice valves in main water supplies
(A) Are used to regulate the flow of water in pipes
(B) Are spaced about 5 km apart
(C) Are usually placed at the summits
(D) All the above

13. The head against which the motor works for lifting water, is
(A) Maximum depth of water table below ground level
(D) All the above

14. Biochemical Oxygen Demand (B.O.D.) of safe drinking water must be
(A) Nil
(B) 5
(C) 10
(D) 15

15. Gravity conduits
(A) Carry water under gravity