Q. A multi-mode optical fiber with a large core diameter has a core refractive index 𝑛1 = 1.5 and cladding refractive index 𝑛2 = 1.4142. The maximum value of 𝜃𝐴 (in degrees) for which the incident light from air will be guided in the optical fiber is ± .
Ans: 29-31
