Question

The plasticity index is the numerical difference between

a.Liquid limit and plastic limit

b.Plastic limit and shrinkage limit

c.Liquid limit and shrinkage limit

d.None of these

Answer 1

The answer is A. Liquid limit and plastic limit

The plasticity index measures the plasticity of the soil. It denotes the amount of moisture, that the soil particles posses in plastic state, while changing from semisolid state to liquid state. It is calculated by the difference of liquid limit and plastic limit of a soil.

Plasticity (PI) = Liquid limit (LL) - Plastic limit (PL).

It is actually a measure of the amount of clay present in a soil. It helps to identify the characteristics of various soils.