Electromagnetic radiation

Electromagnetic radiation

According to classical physics, electromagnetic radiation is nothing but a flow of energy through a space or material medium in a form of electric field and magnetic field all together.

The common electromagnetic wave example is radio wave, gama rays and visible lights that flows linking electric field and magnetic field where both two fields are perpendicular in direction.

According to quantum theory, electromagnetic radiation is flow of photon through space. Photon is defined in physics as a pack of energy denoted as hv, where h is called plank constant and v is velosity, that flows with universal speed of light.

Mass density

Density is more presisely called volumetric mass density or mass
density. mass drnsity means the mass of any objects in its per unit
volume. Methematically mass density is expressed as roh symbol. mass
divided by volume is mass density.

mass density is simplifies by comparing with the density of water. it
is called relative density or specific gravity. If relative density of
any object is less then one, it means that it will be float on water.