Soil Classification MCQ with answer and solution

Concept

Indian Standard Soil Classification System (ISSCS)

Formula

N/A

Step-by-step solution

1. Identify the ISSCS soil symbol 'SM'. 2. Interpret 'S' as Sand (primary soil type) and 'M' as Silt (modifier/fines). 3. Combine them to get Silty Sand, corresponding to Option (a).

Explanation

Option A (Silty Sand) is correct because in the soil classification system, the letter 'S' represents Sand and 'M' represents Silt. Therefore, the symbol 'SM' stands for Silty Sand.

Shortcut

To remember ISSCS soil symbols like 'SM', use the rule "First Letter = Primary Soil, Second Letter = Fine/Modifier": - S = Sand (Primary coarse-grained soil) - M = Silt (Fine-grained modifier, remember 'M' for Silt/Mo) - Result: SM = Silty Sand (Sand with Silt)

Common mistake

A common mistake is selecting option C (Clayey Silt) by confusing the order of the letters, mistakenly thinking 'S' stands for silt and 'M' for main soil component, or confusing 'M' (silt) with 'C' (clay). Another mistake is picking non-standard terminology like option B (Sandy Mud) instead of following standard ISSCS conventions where 'S' is Sand and 'M' is Silt.