MCQ
What will be the minimum angle of incidence such that the total internal reflection takes place from both the surface?.......$^o$
- A$30$
- B$45$
- ✓$60$
- D$75$
✓
Answer
Correct option: C.
$60$
c
For incident surface
For incident surface
$\sin c=\frac{1}{\mu}=\frac{1}{\sqrt{2}}$
$c=45^{\circ}$
then after $T.I.R.$
$\sin c=\frac{\sqrt{3}}{2} \Rightarrow c=60^{\circ}$
minimum incidence angle $=60^{\circ}$
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