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प्रश्न
A glass prism is able to produce the spectrum when white light passes through it, but a glass slab doesn’t produce any spectrum. Explain why it is so.
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उत्तर
The two faces of a glass prism are at an angle (angle of prism) with each other. Therefore, the angle of incidence and the angle of emergence of a light ray become different in the case of a prism. Therefore, when white light gets dispersed after entering a prism, its component colours spread more after refracting through the opposite face of the prism.
In the case of a glass slab, the two opposite faces of the slab are parallel to each other. Therefore, the angle of incidence and the angle of emergence of a light ray remain the same for a glass slab. Therefore, the dispersed light rays combine to form white light after refracting through the second face of the glass slab.
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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.
Describe an activity to show that colours of white light splitted by a glass prism can be recombined to get white light by another identical glass prism. Also draw ray diagram to show the recombination of the spectrum of white light.
The colour of white light which is deviated the maximum on passing through the glass prism is:
(a) blue
(b) indigo
(c) red
(d) orange
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
When we place a glass prism in the path of a narrow beam of white light a spectrum is obtained. What happens when a second identical prism is placed in an inverted position with respect to the first prism? Draw a labelled ray diagram to illustrate it.
If a monochromatic beam of light undergoes minimum deviation through an equiangular prism, how does the beam pass through the prism, with respect to its base?
The splitting of white light into its component colours is called ____________.
Which one of the following is involved for the formation of rainbow in the sky?
The periscope is an optical device with a polished surface that reflects the light falling on it.
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:
