$A$ graph is plotted between angle of deviation $(\delta)$ and angle of incidence $(i)$ for a prism. The nearly correct graph is

Derive ${D_m} = A({n_{21}} - 1)$ for a thin prism.

Three prisms $1, 2,$ and $3$ have a prism angle $A = 60^{\circ}$. Their refractive indices are $1.4, 1.5,$ and $1.6$ respectively. If $\delta_1, \delta_2,$ and $\delta_3$ are their angles of deviation,then:

The angle of minimum deviation produced by a thin prism in air is $\delta_1$. If it is immersed in water,the angle of minimum deviation is $\left[_{a}\mu_{g}=\frac{3}{2}, _{a}\mu_{w}=\frac{4}{3}\right]$.

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

$A$ thin prism of angle $6^{\circ}$ made of glass of refractive index $1.5$ is combined with another prism made of glass of refractive index $1.75$ to produce dispersion without deviation. Then, the angle of the second prism is (in $^{\circ}$)