Geotechnical Engineering

Well Hydraulics

Question 1
Marks : +2 | -2
Pass Ratio : 100%
Which of the following flow is less efficient than radial flow?
Bottom flow
Spherical flow
Turbulent flow
Linear flow
Explanation:
The discharge of spherical flow qs is given by, qs/q =2.3(r/b) log10 1000
Question 2
Marks : +2 | -2
Pass Ratio : 100%
Dupuit’s theory was later modified by _________
Thiem
Darcy
Alam Singh
Louden
Explanation:
The theory proposed by Dupuit’s on radial flow was modified by Thiem in 1906.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
The co-efficient of transmissibility (T) of an aquifer is given by which of the following equation?
T=b k
T=b/k
T=(b k)2
T=k/b
Explanation:
The coefficient of transmissibility T is equals the field of co-efficient of permeability K multiplied by the aquifer thickness b:
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%
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.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
Dupuit’s theory states that, the Darcy’s law equation is not valid near_________
Well face
Top Surface of well
Sides of the well
All of the mentioned
Explanation:
Since the flow of water is not horizontal near wall and the flow no longer remains laminar. Thus, Darcy’s law equation is not valid near the well face.
Question 7
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 8
Marks : +2 | -2
Pass Ratio : 100%
For fine-grained soil,the value of K/A as specified by Marrio is _________
1.00
0.50
0.25
2.00
Explanation:
For fine-grained type of soil, the value of K/A is 0.25 cubic meter per hour, per sq. m of the area under 1m depression head.
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%
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.