$A$ circular disc of which $2/3$ part is coated with yellow and $1/3$ part is with blue. It is rotated about its central axis with high velocity,then it will be seen as

Properly arrange the effects with their reasons:

Effects	Reasons
$(i)$ Rainbow formation	$(a)$ Reflection
$(ii)$ Red colour of danger signals	$(b)$ Scattering
$(iii)$ Different colours of thin oil film and soap bubbles	$(c)$ Chromatic aberration
$(iv)$ Coloured images formed by lenses	$(d)$ Dispersion
$(v)$ Different colours of clouds	$(e)$ Interference

The difference in the number of waves when yellow light propagates through air and vacuum columns of the same thickness is $1$. The thickness of the air column is $....\,mm$. [Refractive index of air $= 1.0003$,wavelength of yellow light in vacuum $= 6000\,\mathring{A}$]

Light of different colours propagates through air:

Fraunhofer lines are obtained in

Evidence for the wave nature of light cannot be obtained from