What should be the maximum acceptance angle at the aircore interface of an optical fibre if \[{{n}_{1}}\]and \[{{n}_{2}}\] are the refractive indices of the core and the cladding, respectively?

\[\left[ {{\tan }^{-1}}\frac{{{n}_{2}}}{{{n}_{1}}} \right]\]

\[{{\sin }^{-1}}({{n}_{2}}/{{n}_{1}})\]

\[{{\sin }^{-1}}\sqrt{n_{1}^{2}-n_{2}^{2}}\]

\[\left[ {{\tan }^{-1}}\frac{{{n}_{1}}}{{{n}_{2}}} \right]\]

What should be the maximum acceptance angle at the aircore interface o

1.	What should be the maximum acceptance angle at the aircore interface of an optical fibre if \[{{n}_{1}}\]and \[{{n}_{2}}\] are the refractive indices of the core and the cladding, respectively?
A.	\[{{\sin }^{-1}}({{n}_{2}}/{{n}_{1}})\]
B.	\[{{\sin }^{-1}}\sqrt{n_{1}^{2}-n_{2}^{2}}\]
C.	\[\left[ {{\tan }^{-1}}\frac{{{n}_{2}}}{{{n}_{1}}} \right]\]
D.	\[\left[ {{\tan }^{-1}}\frac{{{n}_{1}}}{{{n}_{2}}} \right]\]
Answer» C. \[\left[ {{\tan }^{-1}}\frac{{{n}_{2}}}{{{n}_{1}}} \right]\]