The net angular dispersion produced without deviation for crown glass $(\mu =1.56)$ and flint glass $(\mu =1.7)$ is,

$A\mathit{,}B\mathit{,}C\mathit{ }$in the diagram represent rays of light incident upon a face of a right-angled prism. Before emerging from the prism, which ray (or rays) will experience total internal reflection?

Light travels from a medium of refractive index ${\mu }_1$ to another of refractive index ${\mu }_2\left({\mu }_1>{\mu }_2\right)$. For total internal reflection of light, which is NOT true?