Why do fiber optic cables transmit light?
Show answer & explanation
Answer: Total internal reflection keeps light trapped inside the fiber
Total internal reflection keeps light trapped inside the fiber ✓ — Correct! Fiber optics use total internal reflection. Light enters the glass core at specific angles. When it hits the core-cladding boundary, the angle is shallow enough that light reflects completely (no refraction out). Light bounces through the fiber, even around bends, carrying data at light speed. Used in internet, medicine, and telecommunications!
The fiber guides light along a straight path by focusing it — Wrong. Fiber optics can bend! They work through total internal reflection—light hits the glass-cladding boundary at shallow angles, reflecting back internally.
The glass is so pure that light scattering is eliminated — Wrong. High-quality glass reduces scattering, but transmission works through total internal reflection keeping light trapped inside the fiber.
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