"what causes the formation of rainbow" ?
Answers
hope this helps...
spread out into a rainbow.
In a rainbow, raindrops in the air act as tiny prisms. Light enters the raindrop, reflects off of the side of the drop and exits. In the process, it is broken into a spectrum just like it is in a triangular glass prism, like this:
The angle between the ray of light coming in and the ray coming out of the drops is 42 degrees for red and 40 degrees for violet. You can see in this diagram that the angles cause different colors from different drops to reach your eye, forming a circular rim of color in the sky -- a rainbow! In a double rainbow, the second bow is produced because droplets can have two reflections internally and get the same effect. The droplets have to be the right size to get two reflections to work.
The next time you spot a rainbow, you will see it in a whole new light. For more information, check out How Rainbows Work.