62) If e is a void ratio, G is specific gravity, w is water content & S is the degree of saturation, then what is the relationship between them?
a) e = Sw/G
b) e = GS/w
c) e = wGS
d) e = Gw/S
Answer: d) e= Gw/S
- The degree of saturation is simply a ratio of the volume of water to the volume of void. i.e. S= Vw/Vv
- The volume of water volume to the volume of the void is equal to the ratio of the water void ratio to the void ratio.
- i.e., S= Vw/Vv = e_w/e, Where, e_w= Water void ratio
- The water void ratio is the product of void ratio & degree of saturation. i.e., e_w=eS——–(i)
- As we know that the moisture content is the ratio of the weight of water to the weight of dry soil samples.
- i.e., Water content, w =Ww/Wd
- But γ_s = G γ_w
- ∴ w = (e_w γ_w)/(G γ_w )
- ∴ w = e_w/G
- e_w = wG———–(ii)
- From the above-mentioned equation (i) & (ii),
- We get, e_w=eS = wG
- ∴ e= Gw/S