In slow sland filters, the turbidity of raw water can be removed only up to_________________?
(A) 60 mg/litre
(B) 75 mg/litre
(C) 100 gm/litre
(D) 150 mg/litre
Acidity in water is caused due to_______________?
(A) Mineral acids
(B) Free CO2
(C) Iron sulphate
(D) Aluminium sulphate
(D) All the above
Corrosion of well pipes may not be reduced by_________________?
(A) reducing the draw down and the pumping rate
(B) reducing the flow velocity
(C) using thicker pipes
(D) using screens having larger area of openings
(D) none of these
The maximum depth of sedimentation tanks is limited to________________?
(A) 2 m
(B) 3 m
(C) 4 m
(D) 5 m
(D) 6 m
For determining the velocity of flow of underground water, the most commonly used non-empirical formula is________________?
(A) Darcy’s formula
(B) Slichter’s formula
(C) Hazen’s formula
(D) Lacy’s formula
The specific retention is least in case of_______________?
(A) Clay
(B) Sand
(C) Silt
(D) Coarse gravel
The factor affecting per capita demand, is___________________?
(A) size of the city
(B) climatic conditions
(C) pressure in water mains
(D) cost of water
(D) all the above
The assumption on which the trapezoidal formula for volumes is based, is________________?
(A) The end sections are parallel planes
(B) The mid-area of a pyramid is half the average area of the ends
(C) The volume of the Prismoidal is over-estimated and hence a Prismoidal correction is applied
(D) All the above
The brick work is not measured in cu m in case of_______________?
(A) One or more than one brick wall
(B) Brick work in arches
(C) Reinforced brick work
(D) Half brick wall
While estimating the qualities for the construction of a building, the correct metric unit is________________?
(A) Metre for length
(B) Cubic metre for area
(C) Square metres for volume
(D) Litre for capacity