Day 31-Oct 20-PWD-worksheet-Origin of soil,grain size analysis

…………………soil exhibits swelling mainly because it contains montmorillonite

(a)  

Varved clay shows alternating dark and light layers because of —

• Alternating wetting-drying cycles

• Alternate glacial and interglacial deposition

• Organic decomposition

• Differential compaction

The soil type formed in-situ by chemical leaching in warm humid climates is —

• Drift

• Caliche

• Laterite

• Aeolian

Hydrometer method is applicable only for particles finer than —

• 425 µ

• 150 µ

• 75 µ

• 4.75 mm

The most accurate laboratory method of determining water content among the following is —

• Sand bath

• Alcohol method

• Oven drying

• Radiation method

Stoke’s law becomes invalid when Brownian motion dominates.

• True

• False

Core-cutter method is suitable for non-cohesive soils.

• True

• False

The three-phase diagram becomes a two-phase diagram in………… soil and (a)   soil

The method used for in-situ density of cohesionless soils is (a)   .

Specific gravity in hydrometer method is obtained from corrected hydrometer reading R at the (a)