CBSE Class 10 Answered

The raindrops in the atmosphere act like many small prisms.Rainbows are always circular. Rainbows are formed by small water droplets in the air splitting the suns light into colors. We do not see the full circle of the rainbow because the horizon gets in the way. As the sun goes down we are able to see more of the rainbow, and the higher the sun is in the sky the smaller the arc seems. Sometimes people at high elevations, like in planes, see rainbows as full circles because they do not have the horizon to block their view.