What is a common example of an electrical insulator?

Rubber serves as a common example of an electrical insulator due to its properties that prevent the free flow of electric current. Insulators are materials that resist the movement of electric charge, which makes them essential for protecting against electrical shock and maintaining the integrity of electrical circuits. Rubber, being a non-metal, has tightly bound electrons that do not conduct electricity under normal conditions. This characteristic allows rubber to be used effectively in various electrical applications, such as insulating wires and cables, ensuring safety by preventing unwanted electrical conduction.

In contrast, materials like copper and aluminum are excellent conductors, meaning they allow electricity to flow easily through them. Likewise, steel, being a metal, also poses a similar conductive property. Thus, rubber stands out as the suitable choice when discussing electrical insulation.