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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 the 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.
संबंधित प्रश्न
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
A student is observing a diagram showing the path of a ray of light passing through a glass prism. He would find that for all angles of incidence the ray of light bends:
Define the term dispersion of white light.
State the cause of dispersion of white light
As light rays emerge from a glass prism into air, are they refracted towards or away from the normal?
Draw a diagram to show the refraction of light through a glass prism. On this diagram, mark
(i) incident ray
(ii) emergent ray, and
(iii) angle of deviation.
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
Out of the following, the colour of light having the maximum wavelength is:
(a) violet
(b) indigo
(c) green
(d) orange
Out of air and glass, which is optically rarer? Give reason.
- A beam of monochromatic light undergoes minimum deviation through an equiangular prism, how does the beam pass through the prism, with respect to its base?
- If white light is used in the same way as in part (a) above, what change do you expect in the emergent beam?
- What conclusion do you draw about the nature of white light in part (b)?
In an experiment to trace the path of a ray of light through a glass prism for different values of angle of incidence a student would find that the emergent ray:
(A) is parallel to the incident ray
(B) perpendicular to the incident ray
(C) is parallel to the refracted ray
(D) bends at an angle to the direction of incident ray
Complete the ray diagram given below to show the nature of light produced on the screen.
The completed ray diagram is as shown below:
The wavelengths of violet and red light are 4000 Å and 8000 Å respectively. Which of the two has the higher frequency?
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.
In the diagram, a narrow beam of white light is incident on a right-angled isosceles prism. The critical angle of the material of prism for the yellow colour of white light is 45°. Complete the diagram to show the path of blue, yellow, and red colours of white light till they emerge out of the prism.
The sunlight can be split into its constituent colors using ______.
What is dispersion? Explain in detail.
The phenomena of light involved in the formation of rainbow are ______.
Why do we see a rainbow in the sky only after rainfall?
The periscope is an optical device with a polished surface that reflects the light falling on it.
dispersive power of crown glass? Given that µv = 1.5230, µr = 1.5145
In the following diagram showing dispersion of white light by a glass prism, the colours 'P' and 'Q’ respectively are:
State the colour which bends:
- The most.
- The least while passing through a glass prism.
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.
Which colour will show the maximum angle of deviation and which colour will show the minimum angle of deviation?
