Question

Assertion (A): Black cotton soils are clays and they exhibit characteristic property of swelling.
Reason (R): These clays contain Montmorillonite which attracts external water into its lattice structure.

• A. both A and R are true and R is the correct explanation of A
• B. both A and R are true but R is not a correct explanation of A
• C. A is true but R is false
• D. A is false but R is true

Answer 1

The correct option is A both A and R are true and R is the correct explanation of A

(a)
For black cotton soil:
(i) Liquid limit - 40 to 100%
(ii) Plasticity index - 20 to 60%
(iii) Shrinkage limit - 10 to 15%
(iv) Optimum Moisture content - 25% to 30%