a) 0.58
b) 0.66
c) 0.53
d) 0.94

Answer: c
Explanation: Given,
The ratio of saturated unit weight to dry unit weight is equal to 1.2
γ_sat/γ_d= 1.2
Specific gravity of solids G is 2.65
γ_sat = \(\frac{(G+e)}{1+e} \gamma_w \,and\, \gamma_d = \frac{G}{1+e}\gamma_w\)
→ γ_sat/γ_d= \(\frac{(G+e)}{1+e} \gamma_w /\frac{G}{1+e}\gamma_w\)
γ_sat/γ_d = (G+e) / e
→(G+e) / e = 1.2
e = 1.2*G – G
e = 1.2*2.65 – 2.65
e = 0.53.