Question

the refractive index of cladding is a fibre with core refractive index 1.5 and numerical aperture 0.244 is​

Answer 1

Answer:  1.48

Explanation:

The refractive index of the core for an optical fibre is 1.5 and its numerical aperture is 0.244.

You haven't completed the question, I think you mean to calculate the refractive index ( r. i. ) of the cladding​ of that fibre.

Let the r. i. of cladding is  n₂ and the r. i. of core is  n₁

We know that numerical aperture = $N.A. = \sqrt{n_1^2 - n_2^2}$

Given: N.A. = 0.244 and  n₁ = 1.5

$n_2 = \sqrt{n_1^2 - (N.A.)^2 } \\= \sqrt{(1.5)^2 - (0.244)^2} \\= 1.48$

So the refractive index of cladding is a fibre is 1.48

Answer 2

Refractive index is 1.48

Explanation:

Consider

Refractive index of cladding as $r_{1}$

Refractive index of core as $r_{2}$

Numerical aperture N.A = $\sqrt{n_{1} ^{2} - n_{2} ^{2} }$

N.A = 0.244

$n_{1}$ = 1.5

Putting up the values

= $\sqrt{1.5^{2} - 0.244^{2} }$

= 1.48