The formation of rainbow in a sky after its rains is natural phenomena related to dispersion of light.
A rainbow is a natural spectrum of sunlight that formed in the sky after it rains. After it rains, water droplets are suspended in the air. These droplets act as prisms to disperse sunlight into the colours of spectrum.
A primary rainbow
A primary rainbow is formed when sunlight undergoes two refractions and one reflection in water droplet
A primary rainbow has the colour of red on the outside and colour violet on the inside of a curve
A secondary rainbow
A secondary rainbow is formed when sunlight undergoes two refractions and two reflections in a water droplet. Sometimes a secondary rainbow is formed above a primary rainbow.
A secondary rainbow has the colour violet on the outside and the colour of red on the inside the curve. This is the double reflection of light.
A primary rainbow is brighter than a secondary rainbow. The double reflection of light in a water droplet results in the loss of light.
A rainbow is formed if the angle of elevation of the sun is less than 42 degree.
A rainbow will be formed when we spray water in the air towards the sky, if the sun is behind us. A colour spectrum will be seen in he water spray.
