# Unpolrized light passes through 2 polarizers

• Cheezay
In summary, the problem involves unpolarized light passing through two polarizers at an angle of 28.1°. The fraction of the incident intensity that is transmitted through the polarizers can be found by using the equation I/Io = 0.5 x cos^2(theta). This ratio represents the transmitted intensity divided by the incident intensity, and can be used to solve for the fraction of incident intensity that is transmitted.
Cheezay

## Homework Statement

Unpolarized light passes through two polarizers whose transmission axes are at an angle of 28.1° with respect to each other. What fraction of the incident intensity is transmitted through the polarizers?

## Homework Equations

I=.5xIoxcos^2(theta)

## The Attempt at a Solution

Im pretty sure that i have the correct equation, but I'm confused because in the problem I am not given an Incident Intensity, therefore how can i solve for the transmitted intensity? If someone could please start me in the right direction, i would appreciate it very much!

Hi Cheezay,

Cheezay said:

## Homework Statement

Unpolarized light passes through two polarizers whose transmission axes are at an angle of 28.1° with respect to each other. What fraction of the incident intensity is transmitted through the polarizers?

## Homework Equations

I=.5xIoxcos^2(theta)

## The Attempt at a Solution

Im pretty sure that i have the correct equation, but I'm confused because in the problem I am not given an Incident Intensity, therefore how can i solve for the transmitted intensity?
They are not asking for the transmitted intensity, they are asking for the fraction of the incident intensity that is transmitted, which is the ratio of transmitted intensity to incident intensity. Do you see how to solve for that?

No, I'm sorry i don't see how to solve for that. I thought maybe it might be 1/2 the incident intensity, but that answer is not correct.

Cheezay said:
No, I'm sorry i don't see how to solve for that. I thought maybe it might be 1/2 the incident intensity, but that answer is not correct.

The ratio you're looking for is:

(transmitted intensity) / (incident intensity) = I / Io

Using your equation (from your first post), what is that quantity equal to?

Then I/Io= .5 x cos^2(theta). Thanks so much for the help!

## 1. What is unpolarized light?

Unpolarized light refers to light that is oscillating in all directions perpendicular to the direction of its propagation. This means that the electric field of unpolarized light is vibrating in all possible planes.

## 2. How do polarizers work?

Polarizers are filters that only allow light with a specific polarization direction to pass through. They work by absorbing or reflecting light with certain polarization orientations, while allowing light with other orientations to pass through.

## 3. What happens when unpolarized light passes through two polarizers?

When unpolarized light passes through two polarizers, the intensity of the light decreases as each polarizer filters out a portion of the light. The resulting light that passes through the second polarizer will have a polarization direction that is aligned with the second polarizer.

## 4. Can polarized light be converted back to unpolarized light?

Yes, polarized light can be converted back to unpolarized light by passing it through a depolarizer. A depolarizer is a material that randomly changes the polarization direction of light passing through it, effectively converting polarized light into unpolarized light.

## 5. What are some real-world applications of polarizers?

Polarizers have many practical applications, such as in sunglasses, camera filters, 3D glasses, LCD screens, and polarizing microscopes. They are also used in scientific research to study the properties of light and in various optical instruments.

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