Question

Core refractive index -1.55
Cladding refractive index is 1.53wht is numerical aperture for optical fibre

Answer 1

As per the given question,

the refractive index of the core $(n_1)=1.55$

Refractive index of cladding $(n_2)=1.53$

Numerical aperture of the optical fiber$(NA)=\sqrt{n_1^2-n_2^2}$

Now, substituting the values in the above,

$NA=\sqrt{1.55^2-1.53^2}$

$\Rightarrow NA=\sqrt{0.0616}$

$\Rightarrow NA=0.248\sim0.25$