Polarization and decreasing intensity of light to 10%

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Homework Help Overview

The discussion revolves around the problem of determining the angle between the transmission axes of two polarizers needed to reduce the intensity of unpolarized light to 10% of its original intensity. The subject area includes concepts of light polarization and relevant equations.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the application of the Law of Malus and Brewster's law, with some uncertainty about the correct equations to use. There are attempts to manipulate equations to find the angle θ, and questions arise regarding the setup and assumptions involved.

Discussion Status

The discussion is active, with participants sharing their attempts at solving the problem and providing feedback on each other's reasoning. Some guidance has been offered regarding the relevant laws of polarization, but there is no explicit consensus on the final answer yet.

Contextual Notes

Participants note a lack of examples in their textbook, which may be influencing their understanding and approach to the problem.

aChordate
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Homework Statement



In order to decrease the intensity of a beam of unpolarized light to 10% of its original
intensity using two polarizers, what is the required value of θ, the angle between the
transmission axes of the two polarizers?


Homework Equations



tanθB=n2/n1


The Attempt at a Solution



tanθB=n2/n1

I'm not sure how to do this. I read the section on polarization and there are no examples in the book.
 
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aChordate said:

Homework Statement



In order to decrease the intensity of a beam of unpolarized light to 10% of its original
intensity using two polarizers, what is the required value of θ, the angle between the
transmission axes of the two polarizers?


Homework Equations



tanθB=n2/n1


The Attempt at a Solution



tanθB=n2/n1

I'm not sure how to do this. I read the section on polarization and there are no examples in the book.

You seem to have mixed up Brewster's law with the Law of Malus. Check you textbook about the Law of Malus.
 
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So my equation would change to S=So=cos2θ

Would it be:

1/10*I=1/2*I*cos2θ ?


1/5=cos2θ

θ=63.4°

?
 
aChordate said:
So my equation would change to S=So=cos2θ

Would it be:

1/10*I=1/2*I*cos2θ ?


1/5=cos2θ

θ=63.4°

?

Looks good to me.
 

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