30-second summary
Dielectrics
In general, a dielectric is an electrical insulator with high permittivity, which means with high polarisability.
Dielectrics have many applications, but the most significant use is in capacitors. In many capacitors, there is an insulating material such as paper or plastic between the plates. Such a material, called a dielectric, can be used to maintain a physical separation of the plates.
Placing a solid dielectric between the plates of a capacitor serves three functions.
- Mechanical separation
- Electrical isolation – higher voltage possible
- Electric field reduction – higher capacitance
See also: Capacitance
See also: Electric polarisation
See also: Permittivity
Application of Dielectrics
Dielectrics have many applications, but the most significant use is in capacitors. Here are some common applications of dielectrics:
- Capacitors: Dielectric materials are used in the construction of capacitors to provide electrical insulation between the conductive plates and to increase the capacitance of the capacitor.
- Electrical insulation: Dielectric materials are used to insulate electrical wires and components, preventing electrical current from flowing where it is not intended to go. This is important for safety and to prevent electrical interference in electronic devices.
- High-voltage power transmission: Dielectric materials are used to insulate high-voltage power lines, transformers, and other electrical equipment to prevent electrical arcing and other forms of electrical discharge.
- Optical materials: Some dielectric materials are used in optical applications due to their transparency to visible and infrared light. They are used as coatings for lenses and mirrors to improve their reflectivity and prevent degradation.
- Medical applications: Dielectric materials are used in medical devices such as pacemakers and defibrillators to insulate electrical components and prevent interference with biological tissues.
- Energy storage: Dielectric materials are used in capacitors and other energy storage devices to store and release electrical energy.
Overall, dielectric materials are essential in many electrical, optical, and medical applications due to their unique electrical and physical properties.
