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

Correct answer: (a) Total internal reflection

Explanation

Optical fibres carry light by Total Internal Reflection, where light striking the core-cladding boundary is fully reflected back inside.

It occurs only when light travels from a denser to a rarer medium and the angle of incidence exceeds the critical angle.

Refraction (bending across media), diffraction (bending around edges) and scattering cause loss, not guided transmission.