Malus's Law Practice Problems with Solutions

📚 Topic Summary

Malus's Law describes the relationship between the intensity of polarized light and the angle of a polarizer. Simply put, when polarized light passes through a polarizer, the intensity of the light that gets through depends on the cosine squared of the angle between the light's polarization direction and the polarizer's axis. This law is crucial for understanding how polarized sunglasses, LCD screens, and other optical devices work. It's also great practice for trig! 💡

Mathematically, Malus's Law is expressed as: $I = I_0 \cos^2(\theta)$, where $I$ is the intensity of the light after passing through the polarizer, $I_0$ is the initial intensity of the polarized light, and $\theta$ is the angle between the polarization direction and the axis of the polarizer.

🧠 Part A: Vocabulary

Match the terms with their correct definitions:

✏️ Part B: Fill in the Blanks

Complete the following paragraph using the words provided below.

Malus's Law states that the intensity of polarized light after passing through a polarizer is proportional to the __________ of the angle between the light's polarization direction and the polarizer's axis. The formula for Malus's Law is $I = I_0 \cos^2(\theta)$, where $I$ is the final __________, $I_0$ is the initial intensity, and $\theta$ is the __________. Therefore, when $\theta$ is 0 degrees, the intensity is __________, and when $\theta$ is 90 degrees, the intensity is __________.

Words: Angle, Maximum, Intensity, Zero, Cosine Squared

🤔 Part C: Critical Thinking

Explain, in your own words, how polarized sunglasses use Malus's Law to reduce glare.