$A$ certain prism is found to produce a minimum deviation of $38^\circ$. It produces a deviation of $44^\circ$ when the angle of incidence is either $42^\circ$ or $62^\circ$. What is the angle of incidence when it is undergoing minimum deviation (in $^\circ$)?

The principal section of a glass prism is an isosceles triangle $ABC$ with $AB = AC$. The face $AC$ is silvered. $A$ ray of light is incident normally on the face $AB$ and after two reflections, it emerges from the base $BC$ perpendicular to the base. The angle $BAC$ of the prism is: (in $^{\circ}$)

$A$ thin prism of angle $6^{\circ}$ and refractive index for yellow light $(n_{Y}) = 1.5$ is combined with another prism of angle $5^{\circ}$ and $n_{Y} = 1.55$. The combination produces no dispersion. The net average deviation $(\delta)$ produced by the combination is $(\frac{1}{x})^{\circ}$. The value of $x$ is.......

$A$ ray of monochromatic light is incident on one refracting face of a prism of angle $75^o$. It passes through the prism and is incident on the other face at the critical angle. If the refractive index of the material of the prism is $\sqrt{2}$,the angle of incidence on the first face of the prism is.......$^o$.

$A$ thin prism having refracting angle $10^{\circ}$ is made of glass of refractive index $1.42$. This prism is combined with another thin prism of glass of refractive index $1.7$. This combination produces dispersion without deviation. The refracting angle of the second prism should be....$^{\circ}$

At what angle will a ray of light be incident on one face of an equilateral prism,so that the emergent ray may graze the second surface of the prism $(\mu=2)$ (in $^{\circ}$)?