Assertion : In optical fibre, the diameter of the core is kept small. Reason : The small diameter of the core ensures that the fibre should have inside it an angle greater than critical angle needed for total internal reflection.A. If both, Assertion and Reason are true and the Reason is the correct explanation of the Assertion.B. If both, Assertion and Reason are true but Reason is not a correct explanation of the Assertion.C. If Assertion is true but the Reason is false.D. If both, Assertion and Reason are false.

Assertion : In optical fibre, the diameter of the core is kept small.

1.	Assertion : In optical fibre, the diameter of the core is kept small. Reason : The small diameter of the core ensures that the fibre should have inside it an angle greater than critical angle needed for total internal reflection.A. If both, Assertion and Reason are true and the Reason is the correct explanation of the Assertion.B. If both, Assertion and Reason are true but Reason is not a correct explanation of the Assertion.C. If Assertion is true but the Reason is false.D. If both, Assertion and Reason are false.
Answer» Correct Answer - A Both, the Assertion and Reason are true and latter explains the former correctly. Total internal reflection of light takes place if angle of incidence is greater than critical angle. So, small diameter ensures that incident light falls at an angle greater than critical angle.

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