question_answer

What should be the maximum acceptance angle at the aircore interface of an optical fibre if n1 and n2 are the refractive indices of the core and the cladding, respectively  [AIIMS 2005]

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