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%
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 3
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 4
Marks : +2 | -2
Pass Ratio : 100%
The pumping-in test was devised by _________
U.S. Bureau of soil and PRA
U.S. Bureau of reclamation
Indian standard of Bureau
None of the mentioned
Explanation:
The U.S. bureau of Reclamation (Earth Manual, 1960) has devised two types of pumping-in test.
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%
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 7
Marks : +2 | -2
Pass Ratio : 100%
Which of the following test is commonly adopted for determining soil permeability of soil formations?
Pumping-in test and Pumping-out test
Horizontal capillary test
None of the mentioned
All of the mentioned
Explanation:
Pumping-out test is the frequently used field method, as it involves discharging water from the ground.
Question 8
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 9
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 10
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.