An electrical insulator is a material in which electric current does not flow freely. The atoms of the insulator have tightly … See more

Electrical insulation is the absence of electrical conduction. Electronic band theory (a branch of physics) explains that electric charge flows when quantum states of matter are available into which electrons can be exci… See more

A flexible coating of an insulator is often applied to electric wire and cable; this assembly is called insulated wire. Wires sometimes don't use an insulating coating, just air, when a solid (e.g. plastic) coating may be imp… See more

The most important insulation material is air. A variety of solid, liquid, and gaseous insulators are also used in electrical apparatus. In smaller transformers, generators, and electric motors, insulation on the wire … See more

Conductors for overhead high-voltage electric power transmission are bare, and are insulated by the surrounding air. Conductors for lower voltages in distribution may have some insulation but are often bare as wel… See more

Often a broadcasting radio antenna is built as a mast radiator, which means that the entire mast structure is energised with high voltage and must be insulated from the ground. Steatite mountings are used. They have to wit… See more