Question

Which principle is the basis for the transmission of light through fiber optic cables even if the cable is bent?
A) Photoelectric effect
B) Uncertainty principle
C) Light diffraction
D) Light polarization
E) Total internal reflection

Answer 1

To find the solution of this question we need to know about each phenomenon that is given in the option.
Photoelectric Effect: It is the phenomenon in which electrically charged particles are released from or within a material when it absorbs electromagnetic radiation. In simple words, it is the ejection of electrons from a metal plate when light falls on it.
Uncertainty principle: It says that the both position and velocity of an object cannot be measured exactly at the same time, even theoretically. In simple words, the concepts of exact position and exact velocity together have no meaning.
Light diffraction: According to this phenomenon when a light wave passes by a corner or through an opening or slit that is physically the approximate size or even smaller than that of light’s wavelength.
Light polarization: The process of transforming un polarized light into polarized light is known as light polarization. The light waves in which vibrations occur in a single plane are known as polarized light.
Total internal reflection: The phenomenon in which complete reflection of a ray of light within a medium such as water or glass from the surrounding surfaces back into the medium takes place is known as total internal reflection. It occurs if the angle of incidence is greater than the critical angle.

Complete answer:
We need to know about the entire phenomenon given in the option
Out of the given options only in total internal reflection we find that the rays are reflected back within the medium when it is bent with an angle.
So, according to the question light passes through the optical fibers due to total internal reflection even though it is bent.

Hence, option (E) total internal reflection is correct.

Note: We should not confuse total internal reflection with refraction. Refraction occurs at the interface of two mediums and total internal reflection takes place within the medium.