Water Supply Engineering Questions and Answers - Set 03 - ObjectiveBooks

# Practice Test: Question Set - 03

1. 'Shrouding' is essentially provided in
(A) Strainer type wells
(B) Cavity type wells
(C) Slotted type well
(D) All the above

2. The maximum permissible hardness for public supplies is
(A) 95 mg/liter
(B) 105 mg/liter
(C) 115 mg/liter
(D) 125 mg/liter

3. Time of concentration
(A) Is the time taken, for precipitation
(B) Duration of rainfall
(C) Time taken for all the ran off to reach the drain
(D) Time taken for the storm water to travel from the most remote point to the drain

4. The chlorine supply cylinders are generally kept at 38°C to 40°C to prevent
(A) Conversion into crystals
(B) It from burning
(C) It from explosion
(D) None of these

5. For calculation of economical diameter D of a pipe in meters for a discharge Q to be pumped in cumecs, Lea suggested the empirical formula
(A) D = 0.22 √Q
(B) D = 1.22 √Q
(C) D = 2.22 √Q
(D) D = 3.22 √Q

6. An earth formation which, although porous and capable of absorbing water does not provide an appreciable supply to wells, is known as
(A) Aquifer
(B) Aquiclude
(C) Aquifuge
(D) None of these

7. Property of earth to allow water to pass through it, is known as
(A) Perviousness
(B) Porosity
(C) Permeability
(D) Transmissibility

8. Plain chlorination is used for water
(A) Obtained from clear lakes
(B) Consumed during emergencies
(C) Supplies to armies during war
(D) All the above

9. A city supply includes
(A) Domestic water demand
(B) Industrial and commercial water demands
(C) Demand for public uses and fire
(D) All the above

10. The pH value of water is kept slightly less than 7 so that hydrochloride ions may combine with ammonia ions to form
(A) Mono-chloramine (NHCl)
(B) Di-chloramine (NH2Cl)
(C) Nitrogen tri-chloramine (NCl3)
(D) All the above

11. Pick up the correct statement from the following:
(A) Copper pipes are highly resistant to acidic and alkaline water
(B) Wrought iron pipes are lighter than cast iron pipes
(C) Wrought iron pipes corrode quickly and are less durable
(D) All the above

12. Pick up the correct statement from the following:
(A) A hydrograph is a plot of discharge versus time
(B) A mass curve is a plot of accumulated flow versus time
(C) The mass curve continuously rises
(D) All the above

13. If LB and D length, breadth and depth of water in a rectangular sedimentation tank of total discharge Q, the settling velocity, is
(A) Q/H
(B) Q/D
(C) Q/(D × B)
(D) Q/(L × B)

14. The difference in the reservoir level and the lowest point of the water mains is 180 m. The expected pressure due to water hammer is 7.5 kg/cm2 in a pressure conduit of diameter 1 m. Assuming the efficiency of the riveted joints of the pipe as 0.6 and minimum cover 3 mm for corrosion, the thickness of the pipe materials, is
(A) 10 mm
(B) 15 mm
(C) 20 mm
(D) 25 mm

15. If G is the specific gravity of particles of diameter d, the velocity of settlement V in still water at T°C, according to Stoke's law, is
(A) V = 418 (G - 1) d² [(3T + 70)/100]
(B) V = 418 (G - 1) d [(3T - 70)/100]
(C) V = 418 (G - 1) d² [(2T + 70)/100]
(D) V = 418 (G - 1) d4 [(3T + 70)/100]

Show and hide multiple DIV using JavaScript View All Answers

Blogger Comment