Geotechnical Engineering Questions and Answers – Application of Flow Net

Geotechnical Engineering Objective Questions

Civil Engineering MCQs

This set of Geotechnical Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Application of Flow Net”.

1. A flow net can be used for which of the following purpose?

A) Determination of seepage
B) Determination of seepage pressure
C) Determination of hydrostatic pressure
D) All of the mentioned

Answer is D)
Explanation: A flow net can be utilized for determination of seepage, seepage pressure, hydrostatic pressure, and exit gradient.

2. The portion between two successive flow lines is known as ___________

A) Field channel
B) Flow channel
C) Open channel
D) All of the mentioned

Answer is B)
Explanation: The portion between any two successive flow lines is called a flow channel and the portion enclosed between two successive equipotential lines and successive flow lines are known as field.

3. Who was the first to give a graphical method of flow net construction?

A) Casagrande
B) Darcy
C) Forchheimer
D) Kozney

Answer is C)
Explanation: The graphical method of flow net construction first given by Forchheimer in 1930, based on trial sketching.

4. The Darcy’s law governing the flow of water through is related to which of the following law?

A) Ohm’s law
B) Stokes law
C) Faraday’s law
D) None of the mentioned

Answer is A)
Explanation: The electric models suggested by ohm, have the same geometric shape as the soil through which the water flows. And both Darcy and ohm’s law have corresponding analogous quantities.

5. The flow lines and equipotential lines are ____________

A) Parallel
B) Perpendicular
C) Elliptical
D) All of the mentioned

Answer is B)
Explanation: The flow lines and equipotential lines always meet at right angles to one another.

6. The hydrostatic pressure in terms of piezometric head can be calculated from which of the following equation?

A) hW = h – Z
B) hW = h + Z
C) hW = u/γW
D) hW = h/z

Answer is A)
Explanation: The equation hW=h – Z, can be used to plot pressure net representing lines of equal water pressure without the saturated soil mass since all the three quantities in the equation can be expressed a the percentage of total hydraulic head H.

7. The seepage medium can be replaced by ____________electric model having the same geometric shape.

A) Potential divider
B) Insulator
C) Electric conductor
D) Potentiometer

Answer is C)
Explanation: The seepage medium is replaced by an electric conductor consisting of water with some salt or dilutes hydrochloric acid.

8. What will be the hydrostatic pressure if, hW = 30 % and Z = 10 %?

A) 30%
B) 10%
C) 40%
D) 50%

Answer is C)
Explanation: Using the formula, hW = h -Z 30 = h -10 h=30+10 = 40 Hydrostatic pressure, h=40 %.

9. In homogeneous soil, every transition in the shape of curves drawn in flow net must be ____________

A) Smooth
B) Sharp
C) Rough
D) All of the mentioned

Answer is A)
Explanation: According to practical suggestion given by A.Casagrande, every transition in the shape of curve is smooth, being either elliptical or parabolic in shape.

10. The exit gradient can be expressed by which of the following expression?

A) ie = Δ h/i
B) ie = Δ h.i
C) ie = l/h
D) ie = h/i

... Answer is A)
Explanation: ie =Δ h /l, represent gradient formula where Δ h=potential drop and l is the average of last field in the flow net at the exit end.