Optical fibres, though bent in any manner, allows light to pass through. What is the inference that one can draw from it ?
[amp_mcq option1=”The concept that light travels in straight path is wrong” option2=”Light can flow through the optical fibres” option3=”Light can travel through the fibres because of their ductility” option4=”Light can travel through the fibres due to multiple total internal reflections” correct=”option4″]
This question was previously asked in
UPSC NDA-1 – 2015
Optical fibres consist of a core (higher refractive index) surrounded by cladding (lower refractive index). Light entering the core at a suitable angle undergoes total internal reflection at the interface between the core and cladding, bouncing back into the core. This process repeats along the length of the fibre, guiding the light even when the fibre is bent, as long as the bend is not too sharp.