CBSE Class 10 Answered

Even refraction takes place !!

Essentially, the cause of a rainbow is the reflection of sunlight through individual drops of water. Light enters the water and reflects from the opposite side of the water drop, bouncing back through the point of entry. Because the angle or refraction of the light changes as it bounces back, it filters the light into different colors, which arrange themselves with red at the top and violet at the bottom because red is the longest wave length, and violet is the shortest.

When double rainbows form, the light refracts twice, causing a fainter rainbow to mirror above the primary one. Potentially, a triple rainbow could form as well, although it is extraordinarily rare. As soon as the water dissipates enough or the sun moves, the rainbow will disappear, because conditions are no longer optimal for the refraction of the light through the drops. It is also possible for a moonbow to form, although because humans have difficulty distinguishing color in the dark, it usually appears in shades of white and gray.