Question

If plasticity index and percentage of grain size finer than 2 micron m of a clay are 25 and 15 respectively, then the activity ratio is
1. 1.67
2. 10.00
3. 5.00
4. 12.50
5. 7.50

Answer 1

Correct Answer - Option 1 : 1.67

Concept:

Activity of the soil is defined as the ratio of plasticity index of the soil to the percentage of particles finner than 2μ or 0.002 mm.

\({A_t} = \frac{{{I_P}}}{c}\)

Ip = Plasticity index of the soil = wL – wP

wL = Liquid limit of the soil 

wP = Plastic limit of the soil 

Calculation:

Ip = 25%

c = 15 %

\({A_t} = \frac{{25}}{{15}} = 1.67\)