How is the rainbow formed ? What is the minimum condition required to see a rainbow in the sky ?

Asked by ashakumar | 25th Feb, 2011, 09:07: PM

Expert Answer:

Dear student
You need a few things to see a rainbow. The main things are rain, you need that rain to be illuminated by bright sunshine, and the rain must be in the right position relative to you. A primary rainbow is always somewhere on an arc 42 degrees around the shadow of your head (called the anti solar point). So the brightly illuminated rain must be in this direction away from you to see a rainbow. For a secondary bow it is 51 degrees around the shadow of your head. The rainbows are formed after a heavy rain and to watch one, one only has to turn his/her back towards the sun and the rainbow should be visible.

A rainbow is caused by the refraction and internal reflection of light inside rain drops, which results in the white sunlight being separated out into the colours of the rainbow.


Hope this calrifies your doubt.




Answered by  | 25th Feb, 2011, 04:20: PM

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