Engineering Questions with Answers - Multiple Choice Questions
Seepage Analysis – Head, Gradient and Potential
1 - Question
When water flows through a saturated soil mass, piezometric head is the sum of velocity head and position head.
a) True
b) False
View Answer
Explanation: When water flows through a saturated soil mass, total head is the sum of piezometric head, velocity head and position head.
2 - Question
A piezometric surface is the line joining ________
a) water level in piezometers
b) soil stratum
c) equal voids ratio in soil mass
d) equal velocity of flow
View Answer
Explanation: A piezometric surface is the surface formed by the line joining water level in piezometers. The piezometric head is equal to the height of water rise in piezometric tube.
3 - Question
The piezometric head is also called ________
a) position head
b) elevation head
c) velocity head
d) pressure head
View Answer
Explanation: A piezometric head is a measurement of liquid pressure above a vertical datum. Hence piezometric head is also known as pressure head.
4 - Question
The difference between the elevation of water surfaces in piezometers is _______
a) hydraulic gradient
b) velocity
c) head loss
d) depth or length of sample
View Answer
Explanation: Head loss refers to the measurement of energy dissipated in a system due to friction. This energy dissipation is measured by the difference in the elevation of water surfaces in piezometers.
5 - Question
The position head is also called ________
a) total head
b) elevation head
c) velocity head
d) pressure head
View Answer
Explanation: The position or elevation head is the elevation of a point with respect to any arbitrary datum. The elevation head can be taken at any point with respect to a datum.
6 - Question
The elevation head is taken as negative if the point is situated above the datum and positive if below the datum.
a) True
b) False
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Explanation: The datum for elevation head is considered as abscissa of a graph for calculation purpose, where the region above it positive and the region below it is negative.
7 - Question
The total head at any point may be regarded as _________ measure with respect to the datum.
a) potential energy
b) potential energy per unit weight of water
c) unit weight of water
d) volume of water
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Explanation: The total head consists of pressure head, velocity head and position head. The velocity head is considered negligible due to small flow of water.
8 - Question
Total head is the sum of ________
a) piezometric head and velocity head
b) piezometric head and position head
c) position head and velocity head
d) velocity head and pressure head
View Answer
Explanation: The total head is the sum of pressure head, velocity head and position head. The velocity head is considered negligible due to small flow of water. Therefore, total head is the sum of pressure head and position head.
9 - Question
Flow occurs between two points only if _______
a) there is difference in total heads
b) there is no difference in total heads
c) the total heads are equal
d) the total heads are equal to zero
View Answer
Explanation: Flow occurs between two points when there is a difference in elevation of the points which implies to the difference in total heads or potential energies. When there is no difference in total heads, no flow occurs.
10 - Question
The hydraulic gradient is equal to the __________
a) hydraulic head
b) velocity head
c) hydraulic head per unit distance
d) pressure head
View Answer
Explanation: The hydraulic gradient i=hL, Where h= hydraulic head L=distance.
11 - Question
The hydraulic potential at any point is given by _________ a) h=hw±Z
b) h=hw*Z
c) h=hw/Z
d) h=Z/hw
View Answer
Explanation: The hydraulic head is also designated as hydraulic potential. The hydraulic head is the sum of pressure head hw and position head Z.