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Assertion : In optical fibre, the diamet...

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 explaination of the Assertion.

B

If both, Assertion and Reason are true but Reason is not a correct explaination of the Assertion.

C

If Assertion is true but the Reason is false.

D

If both, Assertion and Reason are false.

Text Solution

Verified by Experts

The correct Answer is:
A
Both, the Assertion and Reason are true and latter explain the former correctly. Total internal reflection of light takes place it 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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