An optical fibre transmits light along its length by
Correct answer: A. repeated total internal reflection at the core cladding boundary
- A. repeated total internal reflection at the core cladding boundary
- B. repeated refraction out of the fibre
- C. conducting electricity
- D. absorbing and re-emitting the light
Explanation
The core has a higher refractive index than the cladding, so light striking the boundary beyond the critical angle is reflected without loss and zigzags along even when the fibre bends. This carries far more information than a copper cable and is immune to electrical interference. Endoscopes use bundles of such fibres to see inside the body.
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About Optics
Light is studied through reflection, refraction, dispersion, interference, diffraction and polarization, linking ray behavior with its wave nature. Questions may involve mirrors, lenses, optical instruments, refractive index and image formation, while geometrical optics deals with rays and wave optics explains effects such as interference and diffraction.
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