Assertion : In optical fibre,the diameter of | vedclass

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(A) The Assertion and Reason are both correct,and the Reason provides a correct explanation for the Assertion.In an optical fibre,the core diameter is

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If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.

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(A) The Assertion and Reason are both correct,and the Reason provides a correct explanation for the Assertion.In an optical fibre,the core diameter is kept small to ensure that the light rays entering the fibre strike the core-cladding interface at an angle greater than the critical angle.As shown in the diagram,for a small diameter core,the angle of incidence $\angle A$ at the core-cladding interface is relatively large.For a larger diameter core,the angle of incidence $\angle B$ is smaller.Since the condition for total internal reflection is that the angle of incidence must be greater than the critical angle,a smaller core diameter increases the probability that the light rays will satisfy this condition,thereby ensuring efficient transmission of light through the fibre.

Assertion : In optical fibre,the diameter of the core is kept small.
Reason : This smaller diameter of the core ensures that the fibre should have incident angle more than the critical angle required for total internal reflection.

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Assertion : In optical fibre,the diameter of the core is kept small.Reason : This smaller diameter of the core ensures that the fibre should have incident angle more than the critical angle required for total internal reflection.