A beam of unpolarised light is incident on the boundary between 2 transparent media if the reflected light is completely plane polarised, how is its direction related to the direction of corresponding refracted light?

When unpolarized light is incident on a transparent refracting medium, at a particular angle of incidence the reflected light and refracted light are perpendicular to each other that angle of incident is known as a polarizing angle.


Polarization of reflection, the reflected light gets completely plane-polarized and which makes an angle \(\frac{pi }{2}\) with the refracting light.

According to brewster’s law,

ip + r = 90°

r – is angle of refraction

ip – is polarising angle

r = 90° – ip

by snell’s law

μ1 sin i = μ2 sin r

μ1 = 1 and μ2 = μ

\(\frac{sin i}{sin }=\mu\)


i = ip and

r = 90° – ip

\(\frac{sin {{i}_{p}}}{sin (90{}^circ -{{i}_{p}})}=\mu\) \(\frac{sin {{i}_{p}}}{cos {{i}_{p}}}=\mu\) \(\tan {{i}_{p}}=\mu\) This relation is known as Brewster angle.

Was this answer helpful?


0 (0)

Upvote (0)

Choose An Option That Best Describes Your Problem

Thank you. Your Feedback will Help us Serve you better.

Leave a Comment

Your Mobile number and Email id will not be published. Required fields are marked *




Free Class