Correct Answer - Option 1 : 0.781

__Concept__:

we use the following equation to find out the applied shear stress;

τ = C + σ tanϕ

Where, τ = Shear stress; σ = normal stress

C = cohession of soil; ϕ = angle of internal friction or failure plane;

__Calculation__:

Given:

ϕ = 38∘

As the given soil is cohessionless, hence C = 0

Now, let's put the values into the equation.

∴ τ = 0 + σ × tan 38∘

⇒ τ/σ = tan 38∘

**∴ τ/σ = 0.781**