What is total internal reflection? Mention two applications of optical fibres.

Explanation

When a ray of light traveling from denser medium to rarer medium and is incident at an angle greater than critical angle the ray does not undergo refraction. It undergoes reflection. This phenomenon is called total internal reflection.
Applications of optical fibers
1. used as light pipe to examine internal organs like stomach esophagus, intestine etc.
2. used as decorative lamps.
3. used to transmit and receive electrical signals which are converted into light by transducers.
4. used in the field of communication.