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Question
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.


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Solution
Rainbow-
- Refraction
- Dispersion
- Total internal reflection
RELATED QUESTIONS
A student traces the path of a ray of light through a triangular glass prism for different values of angle of incidence. On analyzing the ray diagrams, which one of the following conclusions is he likely to draw?
(A) The emergent ray is parallel to the incident ray.
(B) The emergent ray bends at an angle to the direction of the incident ray.
(C) The emergent ray and the refracted ray are at right angles to each other.
(D) The emergent ray is perpendicular to the incident ray.
A narrow beam PQ of white light is passing through a glass prism ABC as shown in the diagram.

Trace it on your answer sheet and show the path of the emergent beam as observed on the screen DE.
(i) Write the name and cause of the phenomenon observed.
(ii) Where else in nature is this phenomenon observed?
(iii) Based on this observation, state the conclusion which can be drawn about the constituents of white light.
Study the following diagrams in which the path of a ray of light passing through a glass prism as traced by four students P, Q, R and S is shown:

The student who has traced the path correctly is
(A) P
(B) Q
(C) R
(D) S
Draw a ray diagram to show the dispersion of white light.
(i) A ray of white light breaks up into its components while passing through a glass prism. Draw a ray diagram to show the path of rays.
(ii) Mark the least deviated colour in your diagram
(iii) Why do different coloured rays deviate differently in a prism?
Name the process which is involved in the formation of a rainbow.
The colour of white light which suffers the maximum bending (or maximum refraction) on passing through a glass prism is:
(a) yellow
(b) orange
(c) red
(d) violet
When white light passes through a prism, it ............
Which is optically denser: water or air? Give reason
Explain the cause of dispersion of white light through a prism.
Make the correct choice for each of the following:
Which one of the following Fig correctly shows the path of the ray through the glass block?
Write the range of wavelength of the ultraviolet spectrum.
Sunlight entering through a narrow aperture falls on a prism. Draw a neat labelled ray diagram to show the formation of the spectrum on a screen. Name the colour obtained nearer the base of the prism.
Match the Columns:
| Column ‘A’ | Column ‘B’ |
| The wavelength of red light | (a) 600 nm |
| (b) 700 nm | |
| (c) 500 nm |
Write an Explanation.
Critical angle
Why do we see a rainbow in the sky only after rainfall?
In the following diagram showing dispersion of white light by a glass prism, the colours 'P' and 'Q’ respectively are:

When sunlight passes through water droplets in the atmosphere it gets dispersed into its constituent colours forming a rainbow. A similar phenomenon is observed when white light passes through a prism.
Instead of sunlight, a green-coloured ray is passed through a glass prism. What will be the colour of the emergent ray?
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.
