Question

What is Snell's law Brewster's angle?

Answer 1

Snell's law describes how light bends (refracts) when it passes from one medium to another, like from air to water or from air to glass. It’s based on the idea that light travels at different speeds in different materials. Snell's law is expressed by the equation:

\[
n_1 \sin(\theta_1) = n_2 \sin(\theta_2)
\]

Where:

1. \(n_1\) and \(n_2\) are the refractive indices of the two media.
   

1. \(\theta_1\) is the angle of incidence (the angle the incoming light makes with the normal to the surface).
   

1. \(\theta_2\) is the angle of refraction (the angle the light makes after bending).
   

Brewster’s Angle:

Brewster's angle, also known as the polarization angle, is a special angle of incidence where light that is reflected from a surface is completely polarized in the plane parallel to that surface.

At this angle, the reflected light and refracted light are at right angles (90°) to each other. It occurs when the angle of incidence \(\theta_i\) satisfies the following relationship:

\[
\tan(\theta_B) = \frac{n_2}{n_1}
\]

Where:

1. \(\theta_B\) is Brewster's angle.
   

1. \(n_1\) is the refractive index of the first medium (like air).
   

1. \(n_2\) is the refractive index of the second medium (like glass or water).
   

At Brewster's angle, the reflected light is fully polarized, which means all the reflected waves vibrate in a single direction, parallel to the surface. This is the principle behind polarized sunglasses, which block out glare from reflective surfaces like water or roads.

In summary:

1. Snell's Law governs how light bends when moving between different media.
   

1. Brewster's Angle is the angle where light reflected from a surface is completely polarized.