How do we see a rainbow in a sunny day?

A rainbow is a beautiful natural phenomenon that occurs when sunlight is refracted, or bent, by water droplets in the air. This results in the formation of a spectrum of light appearing in the sky. To understand how we see a rainbow in a sunny day, let's break it down into the following key points:

1. Sunlight as the source:
The primary source of a rainbow is sunlight. Sunlight is composed of various colors that are not visible to the naked eye. These colors include red, orange, yellow, green, blue, indigo, and violet, often abbreviated as ROYGBIV.

2. Water droplets in the air:
To form a rainbow, there must be rain or some form of water droplets in the air. These droplets act as tiny prisms, dispersing and refracting sunlight.

3. Refraction of light:
When sunlight encounters a water droplet, it undergoes refraction, which is the bending of light as it passes from one medium to another with a different density. The different colors of light have different wavelengths, causing them to refract at slightly different angles.

4. Dispersion of light:
As sunlight enters the water droplet, it gets dispersed into its component colors due to the varying angles of refraction. This separation of colors is known as dispersion.

5. Reflection and refraction inside the droplet:
After dispersion, the light undergoes both reflection and refraction inside the water droplet. Some of the light is reflected off the inner surface of the droplet, while the rest continues to refract.

6. Exit and further refraction:
Eventually, the refracted light exits the droplet, bending once again as it enters the air. The different colors continue to refract at different angles, spreading out and forming a circular arc of colors.

7. Circular arc formation:
The circular arc of a rainbow appears because the water droplets in the air are spherical. The observer sees the circular arc as a semicircle, as the lower part of the arc is usually below the horizon.

8. Color sequence:
The color sequence of a rainbow, from the top to the bottom of the arc, is always the same: red, orange, yellow, green, blue, indigo, and violet (ROYGBIV).

9. Angle of observation:
To see a rainbow, you need to be positioned between the sun and the water droplets. The sunlight enters your eyes, and as it passes through the droplets, it is refracted and dispersed, allowing you to witness the vibrant colors.

In conclusion, we see a rainbow in a sunny day due to the refraction, dispersion, and reflection of sunlight by water droplets in the air. The combination of these processes results in the formation of a circular arc of colors that we perceive as a rainbow.

Due to scattering of sunlight after rain..when sunlight falls on droplets present in atmosphere then it scatters light into seven colours forming rainbow