Practice Test: Question Set - 12
1. At break point of chlorination,
- (A) Chlorine
is used to oxidize
- (B) Residual
chloride is zero
- (C) Residual
chloride is maximum
- (D) Residual
chlorine reappears
2. Pick up the correct statement from the following:
- (A) Detention
period for plain sedimentation tanks ranges between 4 to 8 hours
- (B) Detention
period for sedimentation tanks, using coagulants usually ranges between 2 to 4
hours
- (C) The
horizontally flow velocity in sedimentation tanks, is generally limited to 0.3
m/minute
- (D) All
the above
3. The capability of a soil mass of full width and depth to transmit water, is known as
- (A) Porosity
- (B) Permeability
- (C) Transmissibility
- (D) None
of these
4. The head against which the motor works for lifting water, is
- (A) Maximum
depth of water table below ground level
- (B) Maximum
depression head
- (C) Velocity
head
- (D) All
the above
5. By boiling water, hardness can be removed if it is due to
- (A) Calcium
sulphate
- (B) Magnesium
sulphate
- (C) Calcium
nitrate
- (D) Calcium
bicarbonate
6. Derivation of Thiem's formula Q = 2πT (s1 - s2)/2.3 log10 (r2/r1) is based on the assumption
- (A) The
aquifer is homogeneous, isotropic and of infinite depth and area
- (B) The
well is sunk through the full depth of the aquifer
- (C) The
flow lines are radial and horizontal, and the flow is laminar
- (D) All
the above
7. Pick up the correct statement from the following:
- (A) The
volume of underground water extracted by gravity drainage from a saturated
soil, is known as yield
- (B) The
ratio of volume drained to the total volume of material drained, is known as
specific yield
- (C) The
sum of specific yield and specific retention, is equal to porosity
- (D) All
the above
8. Percussion drilling is unsuitable in
- (A) Unconsolidated
sand
- (B) Unconsolidated
gravel
- (C) Quick
sand
- (D) Consolidated
rocks
9. In an artesian aquifer, the draw downs in two observation wells at distances 100 m, and 200 m were found same after one hour and x hours respectively. The value of x, is
- (A) 2
hours
- (B) 4 hours
- (C) 9 hours
- (D) 16 hours
10. Rapid gravity filters can remove bacterial impurities up to a maximum of
- (A) 50 %
- (B) 60 %
- (C) 70 %
- (D) 80 %
11. Continuous flow of water can be expected from
- (A) Gravity
springs
- (B) Surface
springs
- (C) Artesian
springs
- (D) None
of these
12. Reciprocating pumps
- (A) Are
not suitable for variable heads
- (B) Are
four times costlier than centrifugal pumps
- (C) Are
not suitable for pumping water containing sediments
- (D) Single
stroke produce pulsating flow
13. Low turbidity of water is detected by
- (A) Turbidity
tube
- (B) Jackson
turbidity meter
- (C) Baylis
turbidimeter
- (D) Hellige
turbidimeter
14. Pick up the correct statement from the following regarding radial flow centrifugal pumps:
- (A) These
are provided with volute type or turbine type casings
- (B) In
involute type of radial flow centrifugal pump, the impeller discharges into a
gradually expanding spiral casing
- (C) The
efficiency of turbine type of radial flow centrifugal pump, is always higher
than that of volute type
- (D) All
the above
15. Pick up the correct statement from the following:
- (A) Deposition
of calcium carbonate on the inside of the well pipe, causes incrustation of the
pipe
- (B) Incrustation
of the pipe reduces the discharge
- (C) Acidic
waters cause corrosion of the pipes
- (D) All
the above
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