Alum as a coagulant is found to be most effective when pH range of water is______________?
(A) 2 to 4
(B) 4 to 6
(C) 6 to 8
(D) 8 to 10
The detention period and overflow rate respectively for plain sedimentation as compared to sedimentation with coagulation are generally_______________?
(A) less and more
(B) less and less
(C) more and less
(D) more and more
The type of valve which is provided to control the flow of water in the distribution system at street corners and where the pipe lines intersect is_______________?
(A) check valve
(B) sluice valve
(C) safety valve
(D) scour valve
The method of analysis of distribution system in which the domestic supply is neglected and fire demand is considered is________________?
(A) circle method
(B) equivalent pipe method
(C) electrical analysis method
(D) Hardy cross method
The suitable layout of distribution system for a city with roads of rectangular pattern is______________?
(A) grid iron system
(B) dead end system
(C) ring system
(D) radial system
The suitable layout of a distribution system for irregularly growing town is_______________?
(A) dead end system
(B) grid iron system
(C) radial system
(D) ring system
Activated carbon is used for_____________?
(A) disinfection
(B) removing hardness
(C) removing odours
(D) removing corrosiveness
The major disadvantage of lime soda process of water softening is that_________________?
(A) it is unsuitable for turbid and acidic water
(B) huge amount of precipitate is formed which creates a disposal problem
(C) the effluent cannot be reduced to zero hardness
(D) it is unsuitable for softening the water of excessive hardness
Disinfection efficiency is________________?
(A) reduced at higher pH value of water
(B) unaffected by pH value of water
(C) increased at higher pH value of water
(D) highest at pH value equal to 7
The population of a town in three consecutive years are 5000, 7000 and 8400 respectively. The population of the town in the fourth consecutive year according to geometrical increase method is________________?
(A) 9500
(B) 9800
(C) 10100
(D) 10920