**78) Find the value of the density index if the porosity of soil is 30%. The voids ratio of soil in the loosest & densest form is 0.35 & 0.92, respectively. **

- a) 0.805
- b) 0.872
- c) 0.861
- d) 0.881

Komal Bhandakkar Answered question January 5, 2021

**Answer: c) 0.861**

Explanation:

Given Data:

- Porosity of given soil sample = 30% = 30/100 = 0.3
- Voids ratio in the loosest form, e(min.) = 0.35
- Voids ratio in the densest state e(max.) = 0.92

Solution:The formula of void ratio in terms of porosity is, e = n / (1−n) ….(i)

Where e is void ratio & n is the porosity of the soil.

Put, n = 0.3 in equation (i),

then we will get,

∴ e = 0.3(1−0.3)

∴ e = 0.429 ID = (e (max.) – e)/(e(max.)-e(min.))

ID= (0.92–0.429)/(0.92-0.35)

ID= 0.861.Hence, the value of density index is 0.861

Komal Bhandakkar Edited answer January 5, 2021