Question

" PARAGRAPH 1
Light guidance in an optical fiber can be understood by considering a structure comprising of thin solid glass
cylinder of refractive index n₁ surrounded by a medium of lower refractive index n₂. The light guidance in the
structure takes place due to successive total internal reflections at the interface of the media n₁ and n₂ as shown in
the figure. All rays with the angle of incidence i less than a particular value i???? are confined in the medium of
refractive index n₁. The numerical aperture (NA) of the structure is defined as sin i????"
For two structures namely S₁ with n₁= √45 / 4 and n₂ = 3/2, and S₂ with n₁ = 8/5 and n₂ = 7/5 and
taking the refractive index of water to be 4/3 and that of air to be 1, the correct option(s) is(are)
(A) NA of S₁ immersed in water is the same as that of S₂ immersed in a liquid of refractive index 16/3√15
(B) NA of S₁ immersed in liquid of refractive index 6/√15 is the same as that of S₂ immersed in water
(C) NA of S₁ placed in air is the same as that of S₂ immersed in liquid of refractive index 4/√15.
(D) NA of S₁ placed in air is the same as that of S₂ placed in water

Answer 1

Explanation:

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