Does light intensity change with two polarizing sheets?

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SUMMARY

The discussion centers on the behavior of unpolarized light passing through two polarizing sheets with perpendicular axes. After the first polarizing sheet, the intensity of the light is reduced to half of the incident intensity (I = Io/2). After the second sheet, which is oriented at 90 degrees to the first, the intensity becomes zero, as the cosine of 90 degrees is zero (I = 0). The participants confirm that one polarizing sheet does reduce intensity, contrary to the initial assumption that it would not affect the light.

PREREQUISITES
  • Understanding of unpolarized light and its properties
  • Familiarity with the concept of polarization
  • Knowledge of the equation I=(Imax)cos²(Θ)
  • Basic trigonometry, specifically the cosine function
NEXT STEPS
  • Study the effects of varying angles between polarizing sheets on light intensity
  • Research the applications of polarizers in optical devices
  • Explore the concept of Brewster's angle and its relevance to polarization
  • Learn about the principles of light interference and diffraction
USEFUL FOR

Students studying optics, physics educators, and anyone interested in the principles of light behavior and polarization effects.

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Homework Statement



Unpolarized light of intensity Io is incident on two polarizing sheets whose axes are perpendicular.
A) what is the intensity of the light after the first sheet?
B) what is the intensity of the light after the second sheet?

Homework Equations



I=(Imax)cos^2(Θ)

The Attempt at a Solution



A) I thought the intensity would not change since you need two polarizing sheets at certain angles to change the intensity.

B) Intensity is 0? If I plug 90° into the relevant equation, I=0 since cosine at 90 degrees is zero.

Would I be correct in my steps?
 
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Yeah, two linear polarizers tilted at 90 degrees relative to each other will absolutely (or nearly absolutely) block all light from reaching the observer at the other end.
 
Okay thank you! And what about the one sheet? Would I be correct in saying that it would not have any effect regardless of the angle?
 
There would be some reduction in intensity with one polarizer.
 

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