synonymous with insulators in circuits
When we apply an external electric field to an insulator, the electrons in the atom still feel the force and are displaced towards one side as compared to the nucleus as shown in the figure below.
Dipole Moment
a dipole is characterized by a dipole moment, 𝑝⃗, given as 𝑝⃗=𝑞𝑑⃗ where q is the value of the charge and d is the distance between –q and +q charge and the direction of the vector is always from –q charge to +q charge. 𝑝 ⃗⃗⃗⃗ is a microscopic quantum mechanical property.
Polarization vector
where n is the number of atoms per unit volume. The numerator represents the vector sum of the
induced dipole moments contained in a very small volume v. The polarization vector, 𝑃⃗⃗ is a smoothed point function and is the volume density of the electric dipole moment.
Surface charge
induced charge on the surface of the dielectric is given as
where 𝑛̂ is the normal unit vector to the surface pointing out of the dielectric
Volume charge
The induced volume charge is given by the Divergence of 𝑃⃗⃗ as:
