How does the false rainbow form? Why the sequence of its coulour is reverse of VIBGYOR?

Answer 1

'False' rainbow or secondary one forms because of TOTAL INTERNAL REFLECTION through the optical medium (which probably is the rain drops). Total internal reflection can be understood like this: sine of angle of refraction equals sine of angle of incidence into the refractive index. So, when u kep on increasing the angle of incidence, the angle of refratction also keeps on increasing till when a point comes when it esceeds 90 degrees, i.e., when the refracted ray moves back out of the refracting surface (apparently reflected), and one gets an inverted image, hence the sequence opposite of VIBGYOR. Bye. Hope this helps.

Answer 2

Single rainbows are formed by a single total internal reflection inside a water drop. The false rainbow is formed by a double internal reflection and thus appears lower than the original rainbow. Th edouble reflection causes more attenuation since teh light path in teh drop is longer, thus those fals rainbows are harder to see.
Thirdly, the extra reflection causes the second rainbow to be a mirror image of teh first one, therefore its colors are in reverse order