Engineering Questions with Answers - Multiple Choice Questions
Geotechnical Engineering MCQs – Soils Classification – Specific Surface
1 - Question
1. Specific surface is termed as __________ a) Total volume of soil particles b) Total area of soil particles c) Total surface area in a unit mass d) Ratio of total surface to the total volume
Answer: c Explanation: Specific surface is usually defined as the total surface area of the soil particle in a unit mass.
2 - Question
2. Specific surface of the soil particle increase very rapidly, as the grain size ____________ a) Increases b) Decreases c) Bulges d) None of the mentioned
Answer: b Explanation: The subdivision of a mass yields greater surface area than the same mass itself. The specific surface of a mass increases as the grain size decreases.
3 - Question
3. A factor, which is important for the magnitude of specific surface of soil particles is__________ a) Grain shape b) Grain size c) Both size and shape d) Grain molecular structure
Answer: a Explanation: Specific surface varies for different shapes of particle having the same mass. Hence grain shape is important factor for determining specific surface.
4 - Question
4. The specific surface of a soil particle will be ___________ a) Proportional to inter-molecular surface b) Inversely proportional to electric force c) Proportional to the compressive force d) Directly proportional to electric force
Answer: d Explanation: The electrical force responsible for inter-particle effect is proportional to the specific surface.
5 - Question
5. The harmonic diameter, can be found out by using __________ a) kozney’s method b) casagrande method c) Skempton’s method d) Atterberg method
Answer: a Explanation: The harmonic diameter DH can be found by using kozney’s method using the formula F=6/ρs×1/Dn.
6 - Question
6. Specific surface of a soil is related with __________ a) Chemical properties of the soil b) Physical properties of the soil c) General characteristic of the soil d) All of the mentioned
Answer: b Explanation: As specific surface is associated with surface characteristics of a particle, therefore it is related with physical properties.
7 - Question
7. Microscopic soil particles have a very ___________ a) Larger specific surface b) A larger volume c) Small specific surface d) Larger diameter
Answer: a Explanation: As the specific surface increases as the size of the grain decreases. Therefore Microscopic particles have a large specific surface.
8 - Question
8. Specific surface(SS) can also expressed as ________ a) Surface area of the particle per unit volume b) Physical properties of the soil c) Moisture content of the soil d) None of the mentioned
Answer: a Explanation: From the expression, specific surface = surface area of particle/volume of the particle, it can be seen that specific surface is the surface area of a particle.
9 - Question
9. Permeability of the soil depends on __________ a) Size of the soil particle b) Moisture present in soil c) Specific surface of the soil particle d) Density of the soil
Answer: c Explanation: Permeability of soil greatly depends on the specific surface of the soil because of the viscous effects associated with surface characteristics of the grains.
10 - Question
10. Chemical activity of a clay mineral depends on __________ a) Electric charge b) Surface area c) Compactness d) Unit mass
Answer: b Explanation: The chemical activity of the clay mineral depends upon the surface area, because of the electrical charge of clay minerals is high per unit mass.