Question

At what angle should a ray of light be incident on the face of a prism of refracting angle ${60}^{\circ }$ so that it just suffers total internal reflection at the other face? The refractive index of the material of the prism is $1.524$.

Answer 1

Angle of prism A is ${60}^o;\mu =1.524$

$i$ is angle of incidence.

$r_1$ is angle of refraction.

$r_2$ is angle of incidence during exit from other end.

$e$ is 90^o angle of convergent.

$\mu =sine/sin{r}_2\Rightarrow r_2={41}^o$

$r_1=A-r_2={19}^o$

$\Rightarrow \mu =sini/sin{r}_1\Rightarrow i={29.75}^o$