As per USCS, a soil is classified as organic soil if ratio of LL after oven drying to that before oven drying is
- A< 0.75Correct
- B> 0.75
- C< 0.5
- D> 0.5
Solution
Concept
Organic soil criterion
Formula
LL(oven dried)/LL(not dried) < 0.75
Step-by-step solution
1. Organic soils lose liquid limit on drying.
Explanation
A ratio below 0.75 classifies the soil as organic.
Why the other options are wrong
Higher ratios show mineral soil.
Shortcut
< 0.75 = organic.
Correct answer: A) < 0.75