solve for intensity of light

Question

Light with intensity 500 candela and polarization 27 degrees passes through a linear polarizer at 91 degrees. What is the intensity of light after the filter?

Answer 1

According to Malus's law,

I = I₀cos²θ

I₀ = 500 candela

θ = angle between polarization axis of incident polarized light and transmission axis of analyzer

θ = 91° - 27° = 64°

I = (500)cos²(64°) candela ≅ 96.1 candela