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प्रश्न
Why do diamonds sparkle?
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उत्तर
Critical angle for diamond is quite less and is only 24°. Besides these diamonds are cut very sharp, making a large number of the refracting surfaces. Hence when a ray of light enters a diamond, it suffers a series of total internal reflections on account of a very small critical angle. This makes a ray of light literally trapped within the diamond for a little time and this trapped light energy makes a diamond sparkle.
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संबंधित प्रश्न
Express the refractive index μ of a medium in terms of the angle of incidence i in air and the angle of refraction r in a denser medium.
State two advantages of using a right-angle prism as a reflector, rather than a plane mirror.
PQ and PR are two light rays emerging from the object as shown in the figure below:
(i) What is the special name given to the angle of incidence (∠PQN) of ray PQ?
(ii) Copy the ray diagram and complete it to show the position of the image of the object P when seen obliquely from above.
(iii) Name the phenomenon that occurs if the angle of incidence ∠PQN is increased still further.
Choose the correct option.
Consider the following phenomena/ applications: P) Mirage, Q) rainbow, R) Optical fibre and S) glittering of a diamond. Total internal reflection is involved in
Observe the given figure and write appropriate phenomenon of light in the box.
Total internal reflection can take place only if light is travelling from ______.
Optical fibre communication uses the principle of ______.
A particle is projected such that the horizontal range and vertical height are equal. Then the angle of projection is :
Observe the given figure of the raindrop and answer the following questions:
- Label A and B of the given diagram. Why colour will deviate most.
- Name the phenomenon shown in label C.
- Assertion (A): Propagation of light through an optical fibre is due to total internal reflection taking place at the core-cladding interface.
- Reason (R): Refractive index of the material of the cladding of the optical fibre is greater than that of the core.
