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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.
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उत्तर
(i) Dispersion of light
Cause: The dispersion of white light occurs because colors of white light travel at different speeds through glass prism. Different colours undergo different deviations on passing through prism.
(ii) Rainbow is the example of dispersion of light observed in nature.
It is caused due to dispersion of sunlight by water droplets in the atmosphere. It always forms in the direction opposite to the sun.
(iii) White light is a mixture of seven colours. The sequence of colours given by the prism is Violet, Indigo, Blue, Green, Yellow, Orange and Red. VIBGYOR is the acronym for this sequence. The red light bends the least and violet light bends the most.
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संबंधित प्रश्न
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.
In the following diagram, the path of a ray of light passing through a glass prism is shown:
In this diagram the angle of incidence, the angle of emergence and the angle of deviation respectively are (select the correct option):
(A) X, R and T
(B) Y, Q and T
(C) X, Q and P
(D) Y, Q and P
As light rays pass from air into a glass prism, are they refracted towards or away from the normal?
What happens when a ray of ordinary light is passed through a triangular glass prism?
A ray of light moving from an optically rarer to a denser medium
If white light is used in same way what change is expected in the emergent beam?
Answer the following:
What do you mean by dispersion? Name the different colours of light in the proper sequence in the spectrum of light.
Name the scientist who was the first to use a glass prism to obtain the spectrum of sunlight.
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?
