Question

Mention two natural conditions required for construction of canals

Answer 1

Explanation:

Two favourable conditions required for the construction of tanks are:

Two favourable conditions required for the construction of tanks are:The presence of rocky surface as hard rocks prevents the seepage of water deep into the Earth.

Two favourable conditions required for the construction of tanks are:The presence of rocky surface as hard rocks prevents the seepage of water deep into the Earth.Adequate rainfall is required as tanks could be refilled as and when required.

Answer 2

Answer:

The soils displaying a certain degree of plasticity are called cohesive, e.g., the Hungarian Standard Specifications MSZ 4487-58 define a soil as cohesive if the index of plasticity surpasses the value 15.

Plasticity in cohesive soils is due to the interaction between water and the cohesive plastic components present in the soil. These plastic components may be classified into microscopic and submicroscopic clay minerals, with a definite crystal structure (kaolinite, illite, montmorillonite, etc.) and into the amorphous components. The latter are either originally vitreous volcanic ashes, or clay minerals weathered and decomposed by the lime present in the soil. Over the extremely large specific surface (up to 800 m2 /g) of the clay minerals, the unbonded interface atoms produce a strong negative electric field, the role of which surpasses by several orders of magnitude that of gravity related to the negligible mass of these particles.