Correct Answer - Option 2 : Air content
CONCEPT:
Air content:
Air content is defined as the ratio of the volume of air to the volume of voids. It is denoted by ac.
\({{\bf{a}}_{\bf{c}}} = \frac{{{{\bf{V}}_{\bf{a}}}}}{{{{\bf{V}}_{\bf{v}}}}} = \frac{{{\bf{Volume\ of\ air}}}}{{{\bf{Volume\ of\ voids}}}}\)
Porosity:
Porosity is defined as the ratio of the volume of voids to the total volume of soil. It is denoted by n. It varies between 0 and 1.
\({\bf{n}} = \frac{{{{\bf{V}}_{\bf{v}}}}}{{\bf{V}}} = \frac{{{\bf{Volume\ of\ voids}}}}{{{\bf{Total\ volume}}}}\)
Percentage air voids:
Percentage air voids are defined as the ratio of the volume of air to the total volume of soil. It is denoted by na.
\({{\bf{n}}_{\bf{a}}} = \frac{{{{\bf{V}}_{\bf{a}}}}}{{\bf{V}}} \times 100 = \frac{{{\bf{Volume\ of\ air}}}}{{{\bf{Total\ volume}}}} \times 100\)
Degree of saturation:
The degree of saturation is defined as the ratio of the volume of water present in a given soil mass to the total volume of voids in it. It is represented by S
\(S = \frac{{{V_W}}}{{{V_V}}} \times 100\)
S- Degree of saturation
VW - Volume of water
VV - Volume of voids
S + aC=1
