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प्रश्न
Describe how you could demonstrate that white light is composed of a number of colours.
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उत्तर
We can show that white light is composed of a number of colours by passing it through a transparent glass prism. A glass prism is a triangular refracting surface. When a beam of white light enters the prism, the light splits, forming a band of seven colours on a screen placed on the other side of the prism. This splitting of light into its constituent colours is called dispersion of light. The formation of seven colours in a spectrum shows that white light is composed of these seven colours, namely, red, orange, yellow, green, blue, indigo and violet.
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संबंधित प्रश्न
(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?
Fill in the blank with suitable word:
When a ray of light enters a prism, it bends ................ the normal ; as it leaves the prism, it bends ................. the normal.
What is a rainbow? What are the two conditions necessary for the formation of a rainbow in the sky?
The splitting up of white light into seven colours on passing through a glass prism is called:
(a) refraction
(b) deflection
(c) dispersion
(d) scattering
Which of the following colour of white light has the least wavelength?
(a) red
(b) orange
(c) violet
(d) blue
The seven colours in the spectrum of sunlight in order, are represented as :
You are given a disc divided into seven sectors with colours violet, indigo, blue, green, yellow, orange and red in them. What would be its colour when it is rotated rapidly?
Explain the cause of dispersion of white light through a prism.
Draw a labeled ray diagram to illustrate the dispersion of a narrow beam of white light when it passes through a glass prism.
A wave has wavelength 50Å of State its one use.
Answer the following:
What do you mean by dispersion? Name the different colours of light in the proper sequence in the spectrum of light.
How can the presence of ultraviolet radiation be detected?
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.
Observe the given figure and write appropriate phenomenon of light in the box.
Observe the given figure and answer the following questions.
- Which colour light rays bend most?
- Which colour light rays bend least.
- What is the wavelength of violet light rays?
Name the scientist who was the first to use a glass prism to obtain the spectrum of sunlight.
Which one of the following is involved for the formation of rainbow in the sky?
What is Newton’s disc?
A ray of light is incident at 45° on an equilateral prism in the diagram below.
- Name the phenomenon exhibited by the ray of light when it enters and emerges out of the prism.
- State the cause of the above phenomenon mentioned by you.
