Definition and Phenomenons of light.
The Branch of Physics which deals with the study of behaviour, properties and phenomena of light is called Optics.
Light: Light is an electromagnetic wave that provides sensation of sight to eyes.
The phenomenons related with light are Reflection, Refraction, Scattering, Diffraction, Polarisation.
Reflection : It is a phenomenon of bouncing back of light in the same medium after striking on the polished surface. Due to Reflection of light, we can see all the non luminous objects as well. For Example : we can see our image in the mirror by reflection.
Refraction : It is a phenomenon of changing of direction of light when it propagates from one medium to another. It happens due to the change in speed of light when it propagates from rarer to denser medium speed of light decreases hence it bends towards the normal. Light bends away from the normal if it propagates from denser to rarer medium.
For example: coin seems to be raise upwards inside the water while pencil seems to be bent inside water.