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The \mathrm{X-Y} plane be taken as the boundary between two transparent media \mathrm{M_{1}\: and \: M_{2} . \: M_{1} \: in\: \mathrm{Z} \geqslant 0} has a refractive index of \sqrt{2}$ and $\mathrm{M}_{2}  with \mathrm{Z}<0 has a refractive index of \sqrt{3}. A ray of light travelling in \mathrm{M}_{1} along the direction given by the vector \overrightarrow{\mathrm{P}}=4 \sqrt{3} \hat{i}-3 \sqrt{3} \hat{j}-5 \hat{k}, is incident on the plane of separation. The value of difference between the angle of incident in \mathrm{M}_{1} and the angle of refraction in \mathrm{M}_{2}  will be___________ degree.

Option: 1

15


Option: 2

-


Option: 3

-


Option: 4

-


Answers (1)

best_answer

unit vector along incident ray ,

\mathrm{ \hat{e}_1=\frac{\bar{p}}{|\bar{p} \mid}=\frac{4 \sqrt{3}}{10} \hat{i}-\frac{3 \sqrt{3}}{10} \hat{\jmath}-\frac{\hat{k}}{2}}

\mathrm{\hat{n}=\hat{k} (unit \: vector \: along\: normal)}

By law of refraction (vector form)

\mathrm{ \mu_1\left|\left(\hat{e_1} \times \hat{n}\right)\right|=\mu_2\left|\left(\hat{e_2} \times \hat{n}\right)\right| }

\mathrm{\left|\hat{e}_1 \times \hat{n}\right|=\sin i }

\mathrm{\left|\frac{4}{10} \sqrt{3}(-\hat{\jmath})-\frac{3 \sqrt{3}}{10} \hat{i}\right|=\sin i }

\mathrm{\sin \hat{i}=\frac{3}{4}=\frac{i}{1}=53^{\circ} }\rightarrow (1)

\mathrm{\left|\hat{e}_2 \times \hat{n}\right|=\frac{\mu_1}{\mu_2}\left|\hat{e}_1 \times \hat{n}\right| }

\mathrm{\sin r=\sqrt{\frac{2}{3}} \times \frac{3}{4}=\frac{\sqrt{3}}{2 \sqrt{2}} }

\mathrm{\sin r=38^{\circ} }

\mathrm{i-r=15^{\circ}}








 

Posted by

HARSH KANKARIA

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