Unpolarized light with an intensity of (25.0 A) units is passed through two successive polarizing filters, the first with its polarization axis aligned with the vertical and the second with its polarization axis rotated (55.0 B) from the vertical. Find the intensity of the light after passing through the two polarizing filters. Give your answer in same unit as the original light and with 3 significant figures.

the intensity of the light after passing through the two polarizing filters is 4.11 units  

Explanation:

Given the data in the question;

the intensity of an unpolarized light; I₀ = 25.0 units

when the unpolarized light passes through the first polarizer, its intensity reduces to half of its initial value;

⇒ I₁ = I₀/2 = 25/2 = 12.5 units

the angle between the transmission axes of two polarizers is;

∅ = 55° - 0° = 55°

The intensity of the light after passing through two polarizing filters will be;

I₂ = I₁cos²∅      

we substitute

I₂ = 12.5 × cos²(55)

I₂ = 12.5 × 0.3289899

I₂ = 4.11 units

Therefore, the intensity of the light after passing through the two polarizing filters is 4.11 units

it is the second option.