$A$ ray of light is incident on an equilateral glass prism placed on a horizontal table. For minimum deviation,which of the following is true?

$A$ ray of light passes through an equilateral prism such that the angle of incidence is equal to the angle of emergence. If the angle of incidence is $45^o$,the angle of deviation will be.......$^o$.

Calculate the angle of minimum deviation for an equilateral triangular prism of refractive index $\sqrt{3}$. (in $^{\circ}$)

$A$ thin prism $P_1$ with angle $6^{\circ}$ and made from glass of refractive index $1.54$ is combined with another thin prism $P_2$ of refractive index $1.72$ to produce dispersion without deviation. The angle of prism $P_2$ will be

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

$A$ glass prism has a right-triangular cross-section $ABC$,with $\angle A=90^{\circ}$. $A$ ray of light parallel to the hypotenuse $BC$ and incident on the side $AB$ emerges grazing the side $AC$. Another ray,again parallel to the hypotenuse $BC$,incident on the side $AC$ suffers total internal reflection at the side $AB$. Which one of the following must be true about the refractive index $\mu$ of the material of the prism?