Rainbow is produced when sunlight falls on drops of rain. Which of the following physical phenomena are responsible for this?

Rainbow formation is a beautiful demonstration of several optical phenomena. Here's a breakdown: Refraction: When sunlight enters a raindrop, it slows down and bends (refracts) due to the change in medium (air to water). Different wavelengths of light bend at slightly different angles. Dispersion: This difference in bending angles based on wavelength is called dispersion. It's why white sunlight splits into its constituent colors (VIBGYOR). Internal Reflection: After refraction, the light travels to the back of the raindrop and reflects off the inner surface. This is total internal reflection. These three phenomena – refraction, dispersion, and internal reflection – work together to create the rainbow we see. Therefore, option D, '1, 2 and 3', is the correct answer. Why other options are incorrect: A) Dispersion: While crucial, dispersion alone doesn't explain the entire process. B) Refraction: Refraction initiates the process, but doesn't complete it. C) Internal reflection: Internal reflection is a key step, but needs refraction and dispersion to create the spectrum.