Question

Why does sunlight ray undergoes total internal reflection when it hits the inner wall of a raindrop and don't penetrate or refract to escape out of the water medium?

Explain in detail scientifically.



PS : It's a doubt of Class 10 but might require Class 12 knowledge to explain.

CBSE | Class 10 | Class 12 | Physics | Refraction of Light | Formation of Rainbow

Answer 1

hey mate !!!


feel the light from the sun incident on water droplet they will reflect disperse it.


then they reflect it internally


finally it reflect again and again it comes out from rain droplet and due to Dispersion of internal reflection different colour will be reach to observer eyes at different angle.




if you are study about the total internal reflection you come to know that.



when the Ray of light passing from denser to rarer medium and if the angle of incident is less than the critical angle it is known as total internal reflection.


same case is happening in water droplet where the incident ray strike on water droplet at different angle.


ok let suppose a example.



if we have an Opaque object and if you throw a ball it will again comes to us !!!



same here in the case of water droplet where the medium is going denser and denser .




so when a Ray of light a strike on the water droplet due to increase in its denserity ( denser ) it reflect in again rarer medium.



it does not only reflect but it also produce from angle.



due to production of some angle it cause reflecting of the light in same medium

so it will be felt on absorbers eyes.


no the observer can see the formation of rainbow easily.

(for making clearly )

due to total internal reflection is produced from angle in water droplet.


due to producing some angle it reaches into our eyes


are you can see that observers Eyes.



so angle is important in formation of rainbow or you may say that seeing a rainbow.



now I think it is enough!!


for 10th class and you will read more about it in 12 th in the. ray optics .





thanks

Answer 2

Hey there! ☺☻☺

Good Question!!!

Rainbows: [See the figures]

Transversing light rays  and rain drops led to the formation of a Rainbow. When the seven colours of sunlight get mixed, they produce lightning. When the sunlight penetrates the water droplets, it is reflected on the interior surfaces. While it passes through the drops, the light separates into its colors that compose it, which produces an effect very similar to that of a prism. And for a moment, each drop of rain flashes its colors to the observer, before another drop of rain takes its place.


Usually, a rainbow can be observed in the opposite direction of the sun. The light of the rainbow is reflected to the eye, at an angle of 42 degrees in relation to the sunbeam. The arc shape is part of the cone of light that is cut by the horizon. If you travel towards the end of a rainbow, it will move ahead of you, maintaining its shape. Therefore, there is not really an end in a rainbow, nor is there a basin full of gold waiting for you there.


 Because the 45 degree angle of inclination is measured from the eye of each observer, no two people see exactly the same rainbow. Each person is in the center of their own cone of light. From the panoramic point of the top of a mountain or of an airplane, it can be observed in certain occasions, a complete circle of the rainbow. The bright primary rainbow has the color red on the outer edge and blue within itself. In the upper part of the atmosphere, there is always another less bright rainbow, with colors in reverse order. This secondary rainbow, is the result of additional reflection, of the sun's rays through the raindrops.


How does this phenomenon happen?

When the sunlight hits the raindrops they are responsible for producing such an effect, but in some much more than others. The sun's rays involved with the formation of the rainbow come out of the raindrops at an angle of approximately 138 degrees from the direction they were leading before entering them. This is the "angle of the rainbow", discovered by Rene discarded in the year 1637. If the light left at 180 degrees, then it would return where it came from, as the exit angle is only 138 degrees, the light is not reflected exactly towards its origin. This makes it possible for the rainbow to be visible to us, that we do not usually find ourselves exactly between the sun and the rain. So always, if we face a rainbow, the sun will be behind us.

Why is the rainbow semicircular?


 The light of the rainbow is reflected to the eye, at an angle of 42 degrees in relation to the ray of the sun, that is, the sun needs to be on the horizon at no more than 42 degrees of elevation to be visible, that's why you can not see it more than in the early hours of the morning or after mid-afternoon.
The arc shape is part of the cone of light that is cut by the horizon. If you travel to the end of a rainbow, it will move in front of you, maintaining its shape.

Therefore, there is not really an end in a rainbow, nor a pot full of gold waiting for you there. Because the 45 degree angle of inclination is medium from the eye of each observer, no two people see exactly the same rainbow, each person is in the center of their own cone of light. From the panoramic point of the top of a mountain or of an airplane, you can observe certain occasions, a complete circle of rainbows.

Hope It Helps You! ☺☻☺