Dielectric vs Insulator: Difference and Comparison

Dielectric and Insulators are two insulators but with totally different functions and working. The dielectric insulator allows and even saves electricity while the Insulators resist electricity from passing through it and even resist heat.

Although being an insulator, both of them works oppositely and have different uses. One is used to save the electricity to pass while one is used to resist the electricity and the heat.

Key Takeaways

1. Dielectric refers to a material that does not conduct electricity easily but can store electric charge and be polarized.
2. An insulator is a material that does not conduct electricity and is used to separate conductive materials, preventing electric current flow.
3. Dielectrics are used in capacitors, while insulators are used in electrical wiring and equipment to prevent electric shocks.

Dielectric vs Insulator

A dielectric is a poor conductor of electricity but can store electrical energy in an electric field. Dielectrics are used in capacitors and transformers. An insulator does not conduct electricity at all. Insulators are used to protect against electrical shock and short circuits.

The dielectric material can be polarized in an electric field, while insulators, on the other hand, do not get polarized. Talking of the dielectric constant, the dielectric ones have a high number of them, while insulators have a comparatively low dielectric constant.

The electric charges are stored in the dielectric materials, while in the insulators, they are blocked. The insulators are used in wires and cables as they prevent electricity. Hence, there is no chance of an electric shock, while dielectric material is applied in the capacitor.

The dielectric materials check whether the component’s insulation protects the users from electric shocks. In contrast, the insulators are used before any high-potential tests to eliminate any contamination in electrical insulation.

The dielectrics can withstand high electric stress without any conduction. But the insulators restrict any transfer or flow of electrons.

Dielectrics are just insulators that contain no free electrons in them. The dielectrics can be easily polarised when an electric field is applied. In comparison, Insulator is a material that does allow heat or electricity to transfer from it.

Some insulating materials include paper, glass, oil, rubber, and plastic. Although the vacuum is also an insulator, it cannot be considered a material.

Comparison Table

Parameters of comparison	Dielectric	Insulators
Definition	It is an electric insulator that can withstand high electric stress without any conduction.	They are the material or devices that restrict heat transfer or electricity.
Use	It is used to check whether the component’s insulation is sufficiently protecting the users from electric shocks.	It is used before any high-potential tests to eliminate any contamination in electrical insulation.
Polarization	While in the presence of an electric field, the dielectrics can be polarized easily.	The insulators cannot be polarized.
Number of dielectric constants	The dielectrics have a high number of dielectric constants.	The insulators have a comparatively low number of dielectric constants.
Example	Mica, plastic, and oxides of various materials.	Rubber, glass, diamond, wood, and oil

What is Dielectric?

Dielectric is a material with poor electric conductivity, but it inherits an ability to save an electrical charge. They are just insulators that contain no free electrons in them. The dielectrics can be easily polarised when an electric field is applied.

Thus, it can be said that their behaviour in the field of electricity is entirely different from that of conductors.

There are two types of dielectric materials- Polar and Non-Polar. The polar ones are permanent in electric dipole, and their polarization depends on the temperature. While the non-polar ones, the induced electric dipole and their polarization are independent of the temperature.

What is an Insulator?

The insulator is a material that does allow heat or electricity to transfer from it. Some insulating materials include paper, glass, oil, rubber, and plastic. Although a vacuum is also an insulator, it cannot be considered a material.

Mostly, all electrical materials are covered by insulation to avoid any electric current.

Generally, insulators are rated at hundreds of volts, but some used for power distribution are rated as high as hundreds of thousands of volts. Insulators are supported or kept from electrical conductors to make any unintended contact.

Main Differences Between Dielectric and Insulator

1. Dielectric allows and stores the flow of electricity in it and through it, while the insulator, on the other hand, blocks and prevents the flow of electrons and electricity from it.
2. The dielectric material can be polarized in an electric field, while insulators, on the other hand, do not get polarized.
3. The molecules in a dielectric material are weekly bonded, whereas the molecules in an insulator are strongly connected.
4. The dielectric has many dielectric constants, while insulators have a comparatively low dielectric constant.
5. The insulators are used in wires and cables as they prevent electricity. Hence, there is no chance of an electric shock, while dielectric material is applied in the capacitor.
6.  Examples of insulators that prevent the flow and transfer of electricity are- air, glass, plastic, dry wood, and copper. An example of a dielectric is the capacitor.

References

1. https://www.sciencedirect.com/science/article/pii/S0924013607004657
2. https://link.springer.com/chapter/10.1007/978-3-642-77453-9_8