Critical Angles and Total Internal Reflection (Grade 11 NSC Matric Physical Sciences): Flashcards

Light reflects completely back into denser medium at boundary

Angle of incidence where angle of refraction is 90°

Light travels from denser to less dense medium

Angle of incidence > critical angle

$\theta_c = \sin^{-1}\left(\frac{n_2}{n_1}\right)$

48.8°

90°

Inner core and cladding (lower refractive index)

Repeated total internal reflection at core-cladding boundary

100% - no light escapes into second medium