MCQ
If the critical angle for total internal reflection from a medium to vacuum is $30^o $, the velocity of light in the medium is
- A$3 \times {10^8} m/s$
- ✓$1.5 \times {10^8} m/s$
- C$6 \times {10^8} m/s$
- D$\sqrt 3 \times {10^8} m/s$
✓
Answer
Correct option: B.
$1.5 \times {10^8} m/s$
b
(b) $\mu = \frac{1}{{\sin C}} = \frac{1}{{\sin 30}} = 2$
(b) $\mu = \frac{1}{{\sin C}} = \frac{1}{{\sin 30}} = 2$
$ \Rightarrow v = \frac{{3 \times {{10}^8}}}{2} = 1.5 \times {10^8}m/s$
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