State PCS PYQPrelims 2019

UPPCS · Question 125

The phenomenon used in optical fibre for transmission of light energy is

  1. Total internal reflection
  2. Diffraction
  3. Scattering
  4. Refraction
Show answer & explanation

Answer: (A) Total internal reflection

Explanation

Optical fibres guide light by repeated total internal reflection at the core–cladding boundary (core has the higher refractive index).