Dielectric & its properties

'Di' for "opposing" and 'electric' for "electric current".

 So a material is defined as dielectric material if it doesn't conduct electric current and opposes the flow of current. An ideal dielectric material doesn't contain free electrons. There exists a large forbidden gap between valence band and conduction band. That is why the charges are well bounded and can't be set in motion easily. 

A material is defined as dielectric material if

  

Properties: 

                       Conductivity is zero; σ = 0

                       Volume charge density is zero; ρ_v =0

                      Resistivity is infinity

                       Electric and magnetic fields exist in a dielectric

                      Electric and magnetic fields penetrate the dielectric material freely.