$A$ deviation of $5^o$ is observed from a prism whose angle is small and whose refractive index is $1.5$. The angle of the prism is.......$^o$

$A$ parallel beam of light is incident from air at an angle $\alpha$ on the side $PQ$ of a right-angled triangular prism of refractive index $n=\sqrt{2}$. Light undergoes total internal reflection in the prism at the face $PR$ when $\alpha$ has a minimum value of $45^{\circ}$. The angle $\theta$ of the prism is (in $^{\circ}$)

The angle of a prism is $A$. One of its refracting surfaces is silvered. Light rays falling at an angle of incidence $2A$ on the first surface return back through the same path after suffering reflection at the silvered surface. The refractive index $\mu$ of the prism is:

For a small-angled prism,derive the expression for the angle of minimum deviation,${D_m} = A({n_{21}} - 1)$.

For a small angled prism with prism angle $A$,the angle of minimum deviation $(\delta_m)$ varies with the refractive index $(\mu)$ of the prism as shown in the graph.

At what angle of incidence should a ray of light be incident on a face of an equilateral prism if the angle of minimum deviation is $46^{\circ}$ (in $^{\circ}$)?