What type of materials are considered insulators due to their poor conductivity?

Insulators are materials that do not allow electric current to flow easily through them due to their poor conductivity. This characteristic is primarily due to the atomic structure and the lack of free electrons that can move under an electric field.

Fiberglass, glass, polymers, and porcelain are quintessential examples of insulating materials. Fiberglass, for instance, is used widely in electrical applications because it effectively prevents current flow, making it an excellent choice for insulation. Glass acts as a barrier to electrical current while being transparent, which is advantageous in many applications. Polymers, like plastics, are commonly utilized in insulation due to their low conductivity and versatility. Porcelain, often used in insulators for high-voltage applications, offers excellent insulating properties combined with mechanical strength.

In contrast, metals and alloys are known for their high conductivity and are commonly used in electrical wiring. Luminescent materials do not inherently function as insulators and are typically associated with light emission rather than electrical insulation. Conductive ceramics, while offering some insulating properties, generally have improved conductivity compared to traditional insulators. Thus, the combination of fiberglass, glass, polymers, and porcelain is recognized for their significant insulating capabilities.