Test: Specific Surface - Civil Engineering (CE) MCQ

Specific surface is usually defined as the total surface area of the soil particle in a unit mass.

The subdivision of a mass yields greater surface area, than the same mass itself. Specific surface of a mass increases as the grain size decreases.

Specific surface varies for different shapes of particle having the same mass. Hence grain shape is important factor for determining specific surface.

The electrical force responsible for inter-particle effect is proportional to the specific surface.

The harmonic diameter DH can be found by using kozney’s method using the formula
F=6/ρs×1/Dn.

As specific surface is associated with surface characteristics of a particle, therefore it is related with physical properties.

As the specific surface increases as the size of the grain decreases .Therefore Microscopic particles have a large specific surface.

From the expression, specific surface = surface area of particle/volume of particle ,it can be seen that specific surface is the surface area of a particle.

Permeability of soil greatly depends on specific surface of the soil because of the viscous effects associated with surface characteristics of the grains.

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.