Geotechnical Engineering Questions and Answers – Capillary Water

Geotechnical Engineering Objective Questions

This set of Geotechnical Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Capillary Water”.

1. Capillary water is located in part of ___________ soil mass.

A) Within the voids in soil
B) Above the ground water surface
C) Pores in the soil mass
D) Surface of soil particles

Answer is A)
Explanation: Capillary water is the soil moisture located within the interstices and voids of capillary forces.

2. The capillary force of water depends on __________

A) Surface tension of water
B) Pressure in water
C) Conformation of soil pores
D) All of the mentioned

Answer is D)
Explanation: The capillary force of soil moisture depends upon various factors such as surface tension of water, pressure in water relation to atmospheric pressure, and the size and conformation of soil pores.

3. The surface tension of water (TS) is __________

A) 29 dynes per cm
B) 72.8 dynes per cm
C) 0.29 dynes per cm
D) 2.45 dynes per cm

Answer is B)
Explanation: The surface tension = 0.728×10-6 KN/cm at 20°c =072.8 dynes per cm.

4. The coefficient of surface tension depends on which of the following?

A) Chemical nature of liquids
B) Surface area of the liquid
C) Forces acting
D) Atmospheric pressure

Answer is A)
Explanation: Since surface tension is the property of the molecules on the surface of the liquid body, the coefficient depends on the chemical nature.

5. The meniscus formation in capillary tubes always be ___________

A) Convex
B) Concave
C) Equilibrium
D) None of the mentioned

Answer is B)
Explanation: Since the soil pores always carry adsorbed water, the meniscus formation in capillary tube will always be concave.

6. When a capillary tube of uniform-section is lifted from the water surface, water in the tube will be __________

A) Retained
B) Not retained
C) Retained partially
D) None of the mentioned

Answer is A)
Explanation: Since the upward force due to surface tension are balanced by downward force at the lower end there will be no water retained in the tube.

7. The height of capillary rise in capillary tube, depends on ____________

A) Diameter of the tube
B) Surface tension
C) Direction of flow of water
D) All of the mentioned

Answer is C)
Explanation: If a capillary tube is of non-uniform diameter height of capillary rise will be depending upon the direction of flow of water in the tube.

8. The formation of concave meniscus in capillary tubes takes place, only if ___________

A) Inner tubes is dry
B) Tube has non-uniform diameter
C) Inner tube is wet
D) Diameter of the tube is larger

Answer is C)
Explanation: Concave meniscus will only take place if the inner walls of the tubes are initially wet. If the walls are dry, a depressed convex meniscus will be formed.

9. The water in the sandy soil is __________

A) Pore water
B) Ground water
C) Free water
D) Infiltrated water

Answer is A)
Explanation: In the sandy soil there is no significant force of attraction between the soil particles, hence it contains pore water.

10. Coarse grained soil relatively has __________ hygroscopic capacity.

A) High
B) Low
C) Very low
D) Very high

... Answer is B)
Explanation: Coarse-grained soils have relatively low hygroscopic moisture due to their limited specific surface.