Induced Electric Field of Dielectric

Some materials don’t have the free charges to flow on the path of electricity, and some of them do. Materials with free charges are conductors, and materials with no free changes are insulators; dielectric materials fall between these two. Dielectric materials don’t have free charges. Applying a certain limit of an external electric field causes the generation of the electric field inside them but doesn’t cause the flow of charges. This generated field is the induced electric field of a dielectric.

What is an Induced Electric Field?

Applied external electric field on molecules causes the alignment of charges, which causes an internal electric field in the molecule. The generated internal electric field is known as an induced electric field. When we talk about the conductor, the induced electric field becomes equal to the external electric field, so the final electric field becomes zero. We can say that induction of electromagnetic field (EMF) in the circuits causes the conduction of electrons on the wire. That is mainly known as the source of the induced electric field.

The induced electric field is neither stored energy nor a magnetic field. In the case of a battery, it does not need to be present in the circuit, and magnetic fields are not workable in the moving charges. Ultimately we can say that an induced electric field is an electric field completely induced in the molecules of a circuit.

Let’s say Ē can express induced electric field. The work done by the induced electric field for moving a charge in a complete circle can be represented by:

= E.dl

We can also write Faraday’s Law in terms of the induced electric field, 

= E.dl= -d/dt

We can also say that the induced electric field is not storable or capable of doing a network in a close path. So, the electric potential is not associated with the induced electric field.

Dielectric Material

Any dielectric material has the property of being a poor conductor of electricity. Being capable of supporting the electrostatic fields makes this different from the insulator. We can find the use of dielectric material in making the radio frequency transmission. These materials don’t produce heat when applied to an electric field which causes the minimisation of loss of electric field. We also call this law the dielectric loss, and that can be calculated using the proportion of the loss in energy and heat. Examples of dielectric material can be ceramics, distilled water, paper, mica, polyethene, and glass.

The Induced Electric Field of a Dielectric

We have discussed that applying the external electric field in the conductor material causes the generation of the internal electric field that cancels the external electric field. But applying an external electric field on the dielectric material is very different from this. Applying an external electric field on the dielectric material realigns the charges to induce the internal electric field.

However, these materials have no free electrons, which cause the magnitude of the induced electric field to be very low in front of the externally applied electric field. So when we summarise the net electric field inside the material, we find it non-zero and parallel to the externally applied electric field where the magnitude of the inside electric field is very less.

The external field is applied on the polar molecules that cause the polarisation of dielectrics; charges are induced to their opposite charges. But the net charge inside the polar molecule is zero or small in volume. So the dielectric in the external field is equivalent to two oppositely charged sheets with the surface charge densities +σb and –σb. These charges are called bound charges, and these charges are not free to move, but there is an induced electrical field.

Example of Induced Electric Field of Dielectric

We can take an example of balloons rubbed on a wall or the head; they get stuck to the wall after rubbing. The main reason is that after rubbing, the balloon gets charged and polarises the opposite charges on the wall’s surface. 

Conclusion

This article explains the induced electric field of the dielectric. Dielectrics are materials that cannot conduct the charges but hold the electric field inside them. These materials are not conductors but can store the electric field and polarise other materials.

Applied external electric field on molecules causes the alignment of charges, which causes an internal electric field in the molecule. The generated internal electric field is known as an induced electric field. The induced electric field is neither stored energy nor a magnetic field