Question

A ray of light will undergo total internal reflection inside the optical fibre, if it

(a) goes from rarer medium to denser medium
(b)is incident at an angle less than the critical angle
(c) strikes the interface normally
(d)is incident at an angle greater than the critical angle

Answer 1

Total internal reflection occurs when light hits the boundary at an angle greater than the critical angle, as long as it is moving from a denser to a rarer medium. Therefore, the correct option is D.

Step-by-step explanation:

A ray of light will undergo total internal reflection inside the optical fiber if it is incident at an angle greater than the critical angle. This phenomenon occurs at the boundary between two media when the light is traveling from a medium with a higher index of refraction into a medium with a lower index of refraction. Cladding in optical fibers is used to prevent light from being transmitted between fibers in a bundle, ensuring that the light is kept within the core fiber by total internal reflection.