The refractive index of a piece of transparent quartz is the greatest for

Dispersive power depends upon

Two incident monochromatic waves whose wavelengths differ by a small amount $d\lambda$ are separated angularly at $\theta$ and $\theta + d\theta$ with respect to the incident ray. The dispersive power is given by

If the refractive indices of crown glass for red,yellow,and violet colours are $1.5140, 1.5170$,and $1.5318$ respectively,and for flint glass these are $1.6434, 1.6499$,and $1.6852$ respectively,then the dispersive powers for crown and flint glass are respectively:

The refractive indices of violet and red light are $1.54$ and $1.52$ respectively. If the angle of prism is $10^{\circ}$,then the angular dispersion is

Consider the four different cases of dispersion of a light ray which has all the wavelengths from ${\lambda _1}$ to ${\lambda _2}$ (where ${\lambda _1} > {\lambda _2}$). The dotted line represents the light ray of wavelength ${\lambda _{avg}}$. Which ray diagram shows the maximum dispersive power?