$A$ thin prism $P_{1}$ with angle $4^{\circ}$ and made from glass of refractive index $1.54$ is combined with another thin prism $P_{2}$ made from glass of refractive index $1.72$ to produce dispersion without deviation. The angle of prism for $P_{2}$ is (in $^{\circ}$)

The refractive index of a material of a prism of angles $45^o -45^o -90^o$ is $1.5$. The path of the ray of light incident normally on the hypotenuse side is shown in

$A$ glass prism $A$ deviates the red and blue rays through $10^{\circ}$ and $12^{\circ}$ respectively. $A$ second prism $B$ deviates them through $8^{\circ}$ and $10^{\circ}$ respectively. The ratio of their dispersive powers is ($A$ to $B$):

$A$ prism of refractive index $n_{1}$ and another prism of refractive index $n_{2}$ are stuck together (as shown in the figure). $n_{1}$ and $n_{2}$ depend on $\lambda$, the wavelength of light, according to the relation:
${n}_{1}=1.2+\frac{10.8 \times 10^{-14}}{\lambda^{2}} \text{ and } {n}_{2}=1.45+\frac{1.8 \times 10^{-14}}{\lambda^{2}}$
The wavelength for which rays incident at any angle on the interface $BC$ pass through without bending at that interface will be $....\,nm.$

$A$ ray $OP$ of monochromatic light is incident on the face $AB$ of prism $ABCD$ near vertex $B$ at an incident angle of $60^{\circ}$ (see figure). If the refractive index of the material of the prism is $\sqrt{3}$,which of the following is (are) correct?
$(A)$ The ray gets totally internally reflected at face $CD$
$(B)$ The ray comes out through face $AD$
$(C)$ The angle between the incident ray and the emergent ray is $90^{\circ}$
$(D)$ The angle between the incident ray and the emergent ray is $120^{\circ}$

Which one of the following alternatives is $FALSE$ for a prism placed in a position of minimum deviation?