what will happen if an unpolarised light is passed through two perpendicular poloroids

when unpolarised light is passed through first polaroid then its intensity become half of initial because the first polaroid only allows vibration of light thar are parallel to its axis.

And when this light further passed through second polaroid then its intensity become zero because axis of second polaroid is perpendicular to axis of first polaroid. So all the vibration remaining after passing through first polaroid will not allowed to pass.

 

Or you can see mathematically

using malus’ law I = (I₀/2)cos²θ

 

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