Brewster's law states that when light passes from one transparent medium into another at a particular angle known as Brewster's angle, the reflected light will be completely polarized. The document defines Brewster's angle using the refractive indices of the two media and shows the relationship between Brewster's angle and the critical angle. It provides examples of how Brewster's law is applied in polarized sunglasses and photography filters to reduce glare from reflections at surfaces.

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Topic-Brewster’s Law?

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CONTENTS
 What is Brewster’s Law?
 Relation Between Brewster
Angle and Critical Angle
 Application of Brewster’s Law
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When an unpolarized light of known
wavelength is incident on a
transparent substance surface, it
experiences maximum plan
polarization at the angle of
incidence whose tangent is the
refractive index of the substance for
the wavelength.
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What is Brewster’s Law?

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Brewster’s angle is given as:
Ө b = arc tan (n2/n1)
tanӨ b = n2/n1
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Relation Between Brewster
Angle and Critical Angle

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The c r itic al angle is given as :
Ө c = ar c s in ( n1/n2)
s in Ө c = n1/n2
s in Ө c = 1/( n2/n1)
But w e k now that,
tan Ө p = n/s ub>
s in Ө c = 1/tan Ө b
Ther efor e,
Өc = arc s in (1/tan Ө b)
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One general example of the application
of Brewster’s law is polarized
sunglasses. These glasses use the
principle of Brewster’s angle. The
polarized glasses reduce glare that is
reflected directly from the sun and also
from horizontal surfaces like roads and
water. Photographers also use the
same law to reduce the reflection from
reflective surfaces by using a
polarizing filter for the lens.
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Application of Brewster’s Law

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Thank you
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