The correct answer is D. Refraction and reflection of sunlight by water droplets.
A rainbow is an optical and meteorological phenomenon that causes a spectrum of light to appear in the sky when the Sun shines onto droplets of moisture in the Earth’s atmosphere. Rainbows can be full circles. However, the observer normally sees only an arc formed by illuminated droplets above the ground, and centered on a line from the Sun to the observer’s eye.
The rainbow is caused by the refraction of sunlight by water droplets in the Earth’s atmosphere. When sunlight hits a water droplet, it is refracted (bent) as it enters the droplet. The light is then reflected off the back of the droplet and refracted again as it exits the droplet. The angle of refraction depends on the wavelength of the light, which is why we see a spectrum of colors in the rainbow.
The colors of the rainbow are arranged in order of their wavelength, with red being the longest wavelength and violet being the shortest wavelength. The colors are also arranged in order of their frequency, with red having the lowest frequency and violet having the highest frequency.
The rainbow is a beautiful and awe-inspiring phenomenon that has been observed and admired by people for centuries. It is a reminder of the power of nature and the beauty of the world around us.
Here is a brief explanation of each option:
- A. Absorption of sunlight in minute water droplets: This is not the correct answer because rainbows are caused by the refraction and reflection of sunlight, not by its absorption.
- B. Diffusion of sunlight through water droplets: This is also not the correct answer because rainbows are caused by the refraction and reflection of sunlight, not by its diffusion.
- C. Ionisation of water deposits: This is not the correct answer because rainbows are caused by the refraction and reflection of sunlight, not by the ionisation of water deposits.
- D. Refraction and reflection of sunlight by water droplets: This is the correct answer because rainbows are caused by the refraction and reflection of sunlight by water droplets.