The focal lengths of a convex lens for red and blue light are $100 \text{ cm}$ and $96.8 \text{ cm}$ respectively. The dispersive power of the material of the lens is:

The refractive index of flint glass for blue $F$ line is $1.6333$ and red $C$ line is $1.6161.$ If the refractive index for yellow $D$ line is $1.622,$ the dispersive power of the glass is

Dispersive power depends upon

Let us list some of the factors,which could possibly influence the speed of wave propagation:
$(i)$ nature of the source.
$(ii)$ direction of propagation.
$(iii)$ motion of the source and/or observer.
$(iv)$ wavelength.
$(v)$ intensity of the wave.
On which of these factors,if any,does
$(a)$ the speed of light in vacuum,
$(b)$ the speed of light in a medium (say,glass or water),depend?

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

$A$ convex lens,a glass slab,a glass prism,and a solid sphere are all made of the same glass. The dispersive power will be: