Array of light is incident at an angle of incidence ' $i$ ' on one surface of a prism of small angle…
Array of light is incident at an angle of incidence ' $i$ ' on one surface of a prism of small angle $\mathrm{A}$ and emerges normally from the other surface. If the refractive index of the material of the prism is ' $\mu$ ', then the angle of incidence is equal to
$\frac{\mathrm{A}}{2 \mu}$
$\frac{\mathrm{A} \mu}{2}$
$\mathrm{A} \mu$
$\frac{\mathrm{A}}{\mu}$
Solution
Given: $\mathrm{e}=0$
$\therefore \quad r_2=0, A=r_1$
Since ' $\mathrm{i}$ ' is small, Snell's law of refraction can be modified to,
$\begin{aligned}
& \mu=\frac{i}{r_1} \\
\therefore \quad & i=\mu r_1=\mu A
\end{aligned}$