Rainbow is produced when sunlight falls on drops of rain Which of the following physical phenomena a...........

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

1. Dispersion

2. Refraction

3. Internal reflection

Select the correct answer using the codes given below:

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Explanation:

“White” light from the sun comprised of many different wavelengths enters a raindrop. Water has a refractive index different than that of air; so as the white light enters the raindrop, it refracts. However, the angle at which it refracts is determined by the wavelength of the light; and so, different wavelengths refract at different angles. This is known as “dispersion”; a “dispersive medium” is one whose refractive index (which determines how much the light bends) is dependent on the wavelength of the light.

Each individual droplet of water acts as a tiny prism that both disperses the light and reflects it back to our eye.

Since water is more dense than air, light is refracted as it enters the drop. Some of the light will reflect off the back of the drop if the angle is larger than the critical angle (48° for water).