Correct Option
The correct option isDispersion
Explanation
A rainbow is a natural spectrum appearing in the sky after a rain shower. It is caused by the combined optical phenomena of refraction, dispersion, and internal reflection of sunlight by spherical water droplets present in the atmosphere. The water droplets act like small prisms.
Option Analysis
- Regular reflection Regular reflection: Incorrect. Regular reflection occurs when a beam of light falls on a smooth and polished surface, such as a plane mirror. While reflection is part of the rainbow formation process (specifically internal reflection), "regular reflection" does not account for the splitting of colors.
- Dispersion: Correct. Dispersion is the phenomenon of splitting of white light into its constituent colors (VIBGYOR) when it passes through a transparent medium (like a glass prism or a water droplet). This is the primary reason the rainbow appears as a band of distinct colors rather than a white arc.
- Lateral inversion Lateral inversion: Incorrect. Lateral inversion is the phenomenon where the left side of an object appears as the right side in the image, typically observed in plane mirrors. It plays no role in the formation of a rainbow.
- Diffused reflection Diffused reflection: Incorrect. Diffused or irregular reflection occurs when light hits a rough surface and reflects in various directions. This does not lead to the formation of a spectrum.
Key Takeaway: The formation of a rainbow involves three sequential steps: refraction (light enters the droplet), dispersion (white light splits into colors), and internal reflection (light reflects off the back of the droplet). Among the given options, dispersion is the specific phenomenon responsible for the separation of colors.