Reflection and Refraction of light

 

Light is a form of energy that enables us to see. An object reflects the light rays that fall on it. Our eye pupil is black as is takes in the light rays and does not reflect them back.

Light travels in a straight line. Objects can be transparent, opaque and translucent. Transparent objects allow the light rays to pass through them without any obstruction. An Opaque object does not allow any light ray to pass though. Translucent objects partially allow light to pass through. 

The speed of light in vacuum is 3* 10^8

When light bounces back after striking a smooth and polished surface, it bounces back. This phenomenon is called Reflection of light.

When a parallel beam of light falls on a highly smooth surface, it gets reflected and goes only in one direction. When these light rays get reflected in different directions, it is called Diffused or Irregular reflection of light.

When a beam of light enters from one transparent medium to another transparent medium, it changes it's path and bends. This phenomenon is called Refraction of light.

Refractive index is a number that tells us how slow or fast light travels in different mediums. The formula for finding the refractive index :

Speed of light in vacuum/ Speed of light in medium

When a pencil is put into a glass of water, the light ray's travels from the air medium to the water medium. This light ray changes its medium and undergoes refraction. As a result the pencil appears to be broken.