Unpolarized light is incident on a series of polarizing disks. We have three polarizers A, B and C have transmission axes that make angles of 30, 90 and 180 degrees, respectively, measured CW from the vertical y-axis. You want to maximize the relative transmission and can place them in any order. What is the maximum possible relative transmission (is. Final/I0) passing through a series of all three polarizers

Explanation:

Formula for intensity of light after transmission for unpolarised light is

I₀ / 2 , We shall take up 180 degree disk first .

For second transmission , the formula is

I = I₀ Cos²θ , θ is angle between axis of polarizer and axis of vibration.

If we take up 30 degree polariser

I = I₀ / 2  Cos²( 180 - 30 )

= .375 I₀

For third transmission

I_ final = .375 I₀  x cos( 90 - 30 )

= .1875  I₀

Final/I₀ = .1875  

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