Unpolarized light of intensity I0 is incident on two polarizing filters. The transmitted light intensity is I0/10. What is the angle between the axes of the two filters? Express your answer using two significant figures.

Intensity of unpolarized light = I (0)

After first polarization its intensity becomes I (0) / 2

After second polarization its its intensity becomes I (0) / 2 Cos²θ where θ is angle between two polaroid

So I₁ = I (0) / 2 X Cos²θ.

I₁/I (0) = 1/10 =.5 X Cos²θ

Cos ²θ = 0.2

θ = 63 degree.