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प्रश्न
Why do we see a rainbow in the sky only after rainfall?
We see a rainbow in the sky only after the rainfall.” Why?
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उत्तर
Raindrops present in the atmosphere after rainfall serve as a prism and refract, disperse, and internally reflect the incident sunlight, followed by final refraction. The whole sequence of dispersion and internal reflection leads to the formation of the rainbow after rainfall in the sky.
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संबंधित प्रश्न
Why do the component colours of incident white light split into a spectrum while passing through a glass prism, explain
As light rays pass from air into a glass prism, are they refracted towards or away from the normal?
In the formation of spectrum of white light by a prism:
which colour is deviated least?
In the figure given alongside, a narrow beam of white light is shown to pass through a triangular glass prism. After passing through the prism, it produces a spectrum YX on the screen.
Why do different colours of white light bend through different angles with respect to the incident beam of light?
What acts as tiny prisms in the formation of a rainbow?
Which of the following colour of white light is least deviated by the prism?
(a) green
(b) violet
(c) indigo
(d) yellow
Which is optically denser: water or air? Give reason
An object AB is placed in front of a convex lens as shown in fig. 4. Complete the ray diagram and obtain the image formed and state the nature of the image.
Which characteristic property of light is responsible for the blue colour of the sky?
State two properties of ultra-violet radiations which differ from visible light.
Suggest one way, in each case, by which we can detect the presence of Infrared radiations.
In the figure, a beam of light consisting of three colours blue, red, and yellow is incident on a prism and on a rectangular glass block respectively. Complete the diagram by drawings of the refracted and emergent rays.
Match the Columns:
| Column ‘A’ | Column ‘B’ |
| The wavelength of red light | (a) 600 nm |
| (b) 700 nm | |
| (c) 500 nm |
The process of separation of light into its component colours while passing through a medium is called _______.
Rainbow is a beautiful natural phenomenon. It is the combined effect of a natural three processes together produced by light. Write it into the circle.
Observe the given figure and write appropriate phenomenon of light in the box.
Assertion: We can see the rainbow in the sky when the rain starts falling after a spell of bright sunlight.
Reason: The rainbow is formed due to the dispersion of light.
The angle of deviation through a prism is minimum when
- Incident rays and emergent rays are symmetric to the prism.
- The refracted ray inside the prism becomes parallel to its base.
- The angle of incidence is equal to that of the angle of emergence.
- When the angle of emergence has doubled the angle of incidence.
Choose the correct answer from the options given below:
In the following diagram showing dispersion of white light by a glass prism, the colours 'P' and 'Q’ respectively are:
Make a rainbow
Try to make your own rainbow. You can try this project in the morning or in the evening. Stand with your back towards the Sun. Take a hosepipe or a water pipe used in the garden. Make a fine spray in front of you. You can see different colours of rainbow in the spray.
