Unpolarised light is incident on the boundary between two dielectric media, whose dielectric constants are 2.8 (medium $-1$) and 6.8 (medium $-2$), respectively. To satisfy the condition, so that the reflected and refracted rays are perpendicular to each other, the angle of incidence should be ${\tan ^{ - 1}}{\left( {1 + {{10} \over \theta }} \right)^{{1 \over 2}}}$ the value of $\theta$ is __________.
(Given for dielectric media, $\mu_r=1$)
Answer (integer)
7
Solution
<p>We know that</p>
<p>$\tan {\theta _0} = {{{\mu _2}} \over {{\mu _1}}}$</p>
<p>$\tan {\theta _0} = \sqrt {{{6.8} \over {2.8}}} = \sqrt {{{17} \over 7}}$</p>
<p>${\theta _0} = {\tan ^{ - 1}}\sqrt {1 + {{10} \over 7}} \Rightarrow \theta = 7$</p>
About this question
Subject: Physics · Chapter: Optics · Topic: Reflection and Mirrors
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