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 $^{\circ}$)?

$A$ ray of light is incident at an angle '$i$' on one face of a thin angled prism. The ray emerges normally from the other face. If the refractive index of the glass prism is '$n$' and the angle of the prism is '$A$',then the value of '$i$' is:

Given below are two statements :
Statement $I$ : When white light is passed through a prism,the red light bends less than yellow and violet light.
Statement $II$ : The refractive indices are different for different wavelengths in a dispersive medium.
In the light of the above statements,choose the correct answer from the options given below :

For a thin prism,if the angle of prism is $4^{\circ}$ and the refractive index is $1.6$,then the angle of minimum deviation will be . . . . . . . (in $^{\circ}$)

$A$ 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.......$^o$.

Three right-angled prisms of refractive indices $n_1$,$n_2$,and $n_3$ are fixed together using an optical glue as shown in the figure. If a ray passes through the prisms without suffering any deviation,then