In general, a dielectric can be described as a material that conducts electricity very poorly. They are basically insulators and contain no free electrons. Dielectrics are easily polarized when an electric field is applied. Apparently, dielectrics are non-conductive materials. It is an insulating material and does not conduct current well. Dielectric materials can retain an electrostatic charge while dissipating minimal energy as heat. Examples of dielectrics include mica, plastics, glass, ceramics, and various metal oxides.
It should be remembered that dry air is also an example of a dielectric. The information about free charges and bound charges from various physics-related articles is available here. Free charges and bound charges and their general concepts are important topics in physics.
An electric charge reacts when it comes into contact with an electrical conductor and therefore does not pass through the material. However, deviating from position and value results in dielectric polarization. Because matter is polarized, positive charges move towards the electric field and negative charges away from it.
For example, if the field moves along the x-axis, the negative charge will be directed along the negative x-axis. This in turn creates an internal electric field that minimizes the total area inside the dielectric. If there are weakly binding molecules in the dielectric, not only will they polarize, but they will also change direction, aligning the axis of symmetry with respect to the field.
A free charge is not bound to the nucleus and can have energy at zero. Moreover, the energy it possesses is always of a kinetic character. A bound charge, on the other hand, is bound to the nucleus and can only have quantized energy. The energy it possesses is inherently potential and kinetic, and the potential energy is always greater.
From an atomic point of view, dielectric materials fall into two categories.
| Polar molecules | Non-polar molecules |
(i) Permanent electric dipole (ii) Its polarization is  create your own test YOUR TOPIC, YOUR DIFFICULTY, YOUR PACE start learning for free | (i) Induced electric dipole (ii) Its polarization-independent temperature-dependent of temperature |
In general, a polar molecule is one in which the ‘centers of gravity’ of the positive charges and negative charges do not intersect. These molecules are called permanent electric dipoles as these have permanent dipole moments. The common polar molecules are as follows:
In one molecule of H Cl, there is an additional positive charge on the H-ion and an equal negative charge on the Cl-ion. Thus, the molecule has a dipole moment at every instant and is a polar molecule. Some other interesting example of polar molecules is H 2 O.
Similarly, in the water molecule, two O-H bonds are not placed opposite to each other (unlike the CO 2 molecule) but are inclined at an angle of about 105. Here, the hydrogen ion forms a dipole moment with each of the oxygen ions, and there is a net dipole moment p=p 1+p 2.
The increased electric intensity might increase the dipole moment. This is because with increased electric intensity, the distance between the centers of gravity of the positive and negative charges increases which results in an increase in the dipole moment.
In general, a non-polar molecule is one in which the centers of gravity of positive charges and negative charges intersect. Such molecules will not have any permanent dipole moment.
The commonly known examples of non-polar molecules are CO 2, C Cl 4, oxygen O2, nitrogen N2, hydrogen H2, methane CH4, and ethane C2H6.
If we consider a molecule of CO2, the oxygen ions are symmetrically placed with respect to the carbon ion, hence the dipole moment is zero. When the molecule is placed in an electric field E along the line joining the ions, then the oxygen ions get displaced with respect to the carbon ion and the net dipole moment induced is along the direction of E. When the electric field E is applied perpendicular to the line joining the ions, then the directions of the induced dipole moment are again along with the field E.
Therefore, it is generally said that when a non-polar molecule is placed in an electric field, the centers of positive and negative charges shift and the molecule becomes polarized. These molecules are then called induced electric dipoles and their electric dipole moments are called induced electric dipole moments. When the electric field is removed, the induced electric dipole moment disappears.
The induced electric dipole moment is proportional to the applied electric field but almost independent of temperature. Also, an induced dipole is parallel to the electric field at the moment of its creation. The main difference between polar and non-polar molecules is that for polar molecules the temperature depends on the dipole moment and for non-polar molecules, there is no such dependence.
A dielectric material is a material that creates an additional induced electric field when exposed to an external magnetic field.
A vector field representing the density of permanent or induced electric dipole moments in a dielectric material. In an external electric field, molecules acquire an electric dipole moment, and dielectrics are said to be polarized. The electric dipole moment induced by a dielectric material per unit volume is called electric polarization.