Dispersion without Average Deviation and Average Deviation without Dispersion

Two prisms of identical geometrical shape are combined with their refracting angles oppositely directed. The materials of the prisms have refractive indices $1.52$ and $1.62$ for violet light. A violet ray is deviated by $1.0°$ when passes symmetrically through this combination. What is the angle of the prisms?

A thin prism of crown glass $({\mu }_r= 1.515, {\mu }_v= 1.525)$ and a thin prism of flint glass $({\mu }_r= 1.612, {\mu }_v= 1.632)$ are placed in contact with each other. Their refracting angles are $5.0°$ each and are similarly directed. Calculate the angular dispersion produced by the combination.

Three thin prisms are combined as shown in the figure. The refractive indices of the crown glass for red, yellow and violet rays are ${\mu }_{\mathit{r}}\mathit{,}\mathit{ }{\mu }_{\mathit{y}}$ and ${\mu }_{\mathit{v}}$, respectively and those for the flint glass are $\mu {\mathit{\text{'}}}_{\mathit{r}}\mathit{,}\mathit{ }\mu {\mathit{\text{'}}}_{\mathit{y}}$ and $\mu {\mathit{\text{'}}}_{\mathit{v}}$, respectively. The ratio $\frac{A\text{'}}{A}=\frac{x\left({\mu }_v-{\mu }_r\right)}{\left({\mu }_v^{\text{'}}-{\mu }_r^{\text{'}}\right)}$ for no net angular dispersion. Find $x$.

If three identical prisms are combined, is it possible to pass a beam that emerges undeviated? undispersed?

By properly combining two prisms made of different materials, it is possible to

A prism can produce a minimum deviation $\delta$ in a light beam. If three such prisms are combined, the minimum deviation that can be produced in this beam is