Question

Which of the following statement(s) is/are incorrect about rainbow?
(i) Violet is at the top, and red is at the bottom of the rainbow.
(ii) For observing a rainbow, the observer should face towards the Sun.
(iii) Only dispersion of light takes place during rainbow formation.
(iv) All three i.e reflection, refraction and dispersion takes place during rainbow formation.

Answer 1

Rainbow is formed when sunlight is dispersed by rain droplets which are suspended in air. When sunlight enters the raindrop it refracts then it undergoes total internal reflection from the rear end of the droplet surface and again refracted out in the atmosphere and that's how we see a rainbow. So all the given process i.e total internal reflection, refraction, and dispersion take place in the rainbow formation.

In a rainbow red colour is at the top and violet is at the bottom.
The Sun and the rainbow will always be in opposite directions. So, for observing a rainbow, observer's face should be in opposite direction of Sun i.e stand with the sun behind your back.


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