What happens to the intensity of light when it passes through two polarizers at

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Question: What happens to the intensity of light when it passes through two polarizers at an angle of 45 degrees?

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Correct Answer: It is quartered

Solution:

The intensity of light passing through two polarizers at an angle of 45 degrees is quartered.

What happens to the intensity of light when it passes through two polarizers at an angle of 45 degrees?

What happens to the intensity of light when it passes through two polarizers at an angle of 45 degrees?

Step 1: Start with unpolarized light. This light has waves vibrating in all directions.
Step 2: The first polarizer only allows light waves that are aligned with its direction to pass through. This reduces the intensity of the light to half of its original value.
Step 3: Now, the light that comes out of the first polarizer is polarized in one direction.
Step 4: The second polarizer is at a 45-degree angle to the first one. It will allow some of the polarized light from the first polarizer to pass through.
Step 5: To find the intensity of light after the second polarizer, use Malus's Law, which states that the intensity of light passing through a polarizer is equal to the intensity of the incoming light times the cosine squared of the angle between the light's polarization direction and the polarizer's direction.
Step 6: The angle between the first and second polarizer is 45 degrees. The cosine of 45 degrees is 0.707 (approximately).
Step 7: Calculate the intensity after the second polarizer: I = I1 * (cos(45 degrees))^2. Since I1 is half of the original intensity, we have I = (0.5 * I0) * (0.707)^2.
Step 8: (0.707)^2 is approximately 0.5, so I = (0.5 * I0) * 0.5 = 0.25 * I0.
Step 9: This means the intensity of light after passing through both polarizers is one quarter of the original intensity.

Malus's Law – The intensity of polarized light passing through a polarizer is reduced according to the cosine square of the angle between the light's polarization direction and the polarizer's axis.
Multiple Polarizers – When light passes through multiple polarizers, the intensity is affected by the angle between each polarizer and the light's polarization direction.