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Question: Answered & Verified by Expert
Assertion : In optical fibre, the diameter of the core is kept small.
Reason : The smaller diameter of the core ensures that the fibres should have incident angle more than the critical angle required for total internal reflection.
PhysicsRay OpticsAIIMSAIIMS 2015
Options:
  • A If both assertion and reason are true and reason is the correct explanation of assertion.
  • B Ifboth assertion and reason are true but reason is not the correct explanation of assertion.
  • C If assertion is true but reason is false.
  • D If both assertion and reason are false.
Solution:
2910 Upvotes Verified Answer
The correct answer is: If assertion is true but reason is false.
Diameter of a single mode optical fibre lies between 8 to $10.5 \mu \mathrm{m}$
Critical angle for total internal reflection does not depend on width of media.

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