Question

Periscope works on the principle of:
A. refraction of light
B. reflection of light
C. diffraction of light
D. scattering of light

Answer 1

Hint – In order to solve this problem, we need to know that a periscope is an optical instrument that uses a prism, lens or mirror system to reflect images through a tube. The light hits another mirror at the bottom of the periscope and is then mirrored in the viewer's eye. Therefore, the periscope acts according to the concept of absolute internal reflection.

Complete step-by-step answer:
A periscope is based on the Laws of Reflection, which says that the light from the object falls on a mirror at an angle of 45 degrees from the surface and is mirrored. The mirrored light then falls on another mirror and is mirrored again until it enters the human eye.
The periscope operates on the theory of light reflection (multiple reflections from plane mirrors).

Hence, the right option is B.

Note – Periscope follows the laws of reflection of light and the reflection is a complete internal reflection. In total internal reflection light falls from denser to rarer medium then reflects back in denser medium itself. The condition happens when the angle of incidence is greater than a certain angle of restriction, called the critical angle. Diamond is a perfect example of absolute internal reflection. Diamond has the highest refractive index, but can increase the amount of total internal reflection by being correctly cut to make the diamond sparkle. The fiber optic cables relay light as they pass through the cables by bouncing from side to side.