NEET-XII-Physics
18: Geometrical Optics
- #3Why does a diamond shine more than a glass piece cut to the same shape?Ans : A diamond shines more because of the phenomenon of total internal reflection (TIR). The refractive index of diamond is ≈2.4 and that of glass is ≈1.5.
By using the relation `` \mu =\frac{1}{\,\mathrm{\,sin\,}C}``, where C is the critical angle, we get refractive index (μ).
For a large refractive index, the value of the critical angle is small. Thus, for the diamond, the critical angle for total internal reflection is much smaller than that of the glass. Therefore, a great percentage of incident light gets internally reflected several times before it emerges out.
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