Index Properties MCQ with answer and solution

Concept

Air content is the ratio of the volume of air voids to the total volume of voids.

Formula

a_c = V_a / V_v = 1 - S

Step-by-step solution

1. Void ratio e = V_v / V_s. 2. Porosity n = V_v / V. 3. Degree of saturation S = V_w / V_v. 4. Air content a_c = V_a / V_v. 5. So the answer is (B) Air Content.

Explanation

Air content compares the air volume with the total void volume. It is linked to the degree of saturation by a_c = 1 - S. Do not confuse it with percentage air voids, n_a = V_a / V.

Why the other options are wrong

(A) Void ratio is V_v / V_s. (C) Degree of saturation is V_w / V_v. (D) Porosity is V_v / V.

Shortcut

Air content + Degree of saturation = 1.

Common mistake

Confusing air content (V_a / V_v) with percentage air voids (V_a / V).