Geotechnical Engineering

Well Hydraulics

Question 1
Marks : +2 | -2
Pass Ratio : 100%
The discharge of an open well can be determined by, which of the following method?
Constant head test
Falling head test
Recuperation test
None of the mentioned
Explanation:
In the recuperation test, water level can be depressed to any level and the discharge from the well can be calculated.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
Volume of water dv entering the well, when the head recuperates by dh is ___________
dV=A/dh
dV=A.dh
dV=Khdt
dV=K.A
Explanation:
Volume of water entering the well, when the head recuperates by dh is given by the equation: dV=Adh
Question 3
Marks : +2 | -2
Pass Ratio : 100%
In most of the confined aquifers,the value of storage coefficient ranges between __________
0.05 to 0.0005
0.5 to 0.005
0.00005 to 0.005
0 to 5
Explanation:
By pumping test method, the value of storage coefficient ranges was found to be in between 0.00005 to 0.005.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
An open well has relatively larger diameter at __________
Base
Middle
Top
Near the bottom
Explanation:
As the velocity of water is larger at the base, the width of base widens up and its diameter increases.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
The value of specific yield SY, of an aquifer depends on ___________
Grain size
Compaction of stratum
Grain shape
All of the mentioned
Explanation:
Since specific yield is the volume of water drained, the drainage of water depend on grain size, shape and compaction of stratum in the soil.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
The type of hydraulics of flows towards open well is __________
Radial flow
Bottom flow
Adjacent flow
All of the mentioned
Explanation:
If the well is open, radial flow takes place all around the well and there is no flow from the bottom of the well.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
Which of the following well, does not penetrate to the full depth of an aquifer?
Fully penetrating artesian gravity wall
Partially penetrating artesian wall
Partially penetrating artesian gravity wall
All of the mentioned
Explanation:
A partially penetrating artesian well is the one in which the well screen does not penetrate to the full depth of the confined aquifer. Such wells extend only partly through the water bearing stratum.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
When two wells, situated near each other is discharged,the total discharge will __________
Increases
Decreases
Remains the same
None of the mentioned
Explanation:
When two wells are discharged, their drawdown curves intersect within their radii of zero drawdown. Thus the total discharge is increased.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
According to Dupuit’s theory,the velocity of flow is proportional to__________
Sine of hydraulic gradient
Tangent of hydraulic gradient
None of the mentioned
All of the mentioned
Explanation:
Based on the assumption proposed by Dupuit’s theory, the velocity of flow is proportional to the tangent of the hydraulic agent instead of its sine.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
In Recuperation test, the expression (K/A ) is known as ___________
Specific yield and Specific capacity
Coefficient of permeability
None of the mentioned
All of the mentioned
Explanation:
K/A is known as the specific yield or specific capacity of an open well, in cubic meter per hour per square meter of the area through which water percolates.