Advertisements
Advertisements
प्रश्न
- 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.
विकल्प
If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
If Assertion is true but Reason is false.
If both Assertion and Reason are false.
Advertisements
उत्तर
If Assertion is true but Reason is false.
Explanation:
Propagation of light through an optical fibre is due to total internal reflection taking place at the core-cladding interface. The claim is correct.
One requirement for total internal reflection is that light goes from a denser to a rarer medium. Total internal reflection occurs in optical fibre as light passes from the core to the cladding. As a result, the core's refractive index should be larger than that of the cladding. As a result, the reason is untrue.
APPEARS IN
संबंधित प्रश्न
The figure shows a ray of light falling normally on the face AB of an equilateral glass prism having refractive index`3/2`, placed in water of refractive index `4/3`.Will this ray suffer total internal reflection on striking the face AC? Justify your answer.
Angle of deviation is the angle which the ______ ray makes with the direction of ______ray.
What do you understand by the deviation produced by a prism? Why is it caused?
Total internal reflection occurs only when a ray of light passes from a ______ medium to a ______ medium.
Total internal reflection can take place only if ______.
The adjacent diagram shows two right-angled isosceles prisms A and B. Complete the diagram to show the path of rays P and Q emerging out of the prism B. What principles have you used to complete the diagram?
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.
A bundle of glass threads, each of which is capable of transmitting messages using light waves is called ______.
Optical Fibres are based on the phenomenon of dispersion.
State two differences between normal reflection and total internal reflection.
