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प्रश्न
State one factor on which a critical angle for a given pair of media depends. The critical angle for the glass-air interface is 45° for the yellow light. Will it be equal to, less than or greater than 45° for (i) red light, (ii) blue light?
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उत्तर
The value of the critical angle for a given pair of media depends on the colour of light.
(Hint: Remember VIBGYOUR Violet has minimum ic whereas Red has maximum).
(i) For red light, the critical angle will be greater than 45°.
(ii) For blue light, the critical angle will be less than 45 °.
संबंधित प्रश्न
In the given figure PQ and PR are the two light rays emerging from an object P. The ray PQ is refracted as QS.
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- Name the phenomenon that occurs if the angle of incidence ∠PQN is increased.
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- Draw in the diagram the refracted ray for the incident ray PR and hence show the position of image of the object P by the letter P’ when seen vertically from above.
Write the necessary conditions for the phenomenon of total internal reflection to
occur ?
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- Reason (R): Refractive index of the material of the cladding of the optical fibre is greater than that of the core.
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