A) \[\sin \theta \ge \frac{8}{9}\]
B) \[\frac{2}{3}<\sin \theta <\frac{8}{9}\]
C) \[\sin \theta \le \frac{2}{3}\]
D) None of these
Correct Answer: A
Solution :
[a] The phenomenon of total internal reflection takes place during reflection at P. \[\sin \theta =\frac{1}{\begin{matrix} \omega \\ g \\ \end{matrix}\mu }\] ...(i) When \[\theta \] is the angle of incidence at P Now, \[\begin{matrix} \omega \\ g \\ \end{matrix}\mu =\frac{\begin{matrix} a \\ g \\ \end{matrix}h}{\begin{matrix} \omega \\ g \\ \end{matrix}\mu }=\frac{1.5}{4/3}=1.125\] Putting in (i), \[\sin \theta =\frac{1}{1.125}=\frac{8}{9}\] \[\therefore \] sin\[\theta \] should be greater than or equal to\[\frac{8}{9}\]You need to login to perform this action.
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