Which materials are commonly used for electrical wire insulation?

The selection of PVC (Polyvinyl Chloride), rubber, and thermoplastic elastomer as common materials for electrical wire insulation is based on their excellent insulating properties and durability.

PVC is widely utilized due to its versatility, resistance to moisture, and flame-retardant characteristics, making it suitable for various indoor and outdoor applications. Rubber, particularly in its synthetic forms, offers flexibility and high dielectric strength, which helps in preventing electrical leakage while allowing for easy handling in installation. Thermoplastic elastomers combine the benefits of rubber and plastics, providing flexibility, resistance to environmental factors, and good thermal performance. These properties make these materials ideal for insulating electrical wires, ensuring safety and reliability in electrical installations.

Other materials mentioned in the incorrect options have limitations in terms of effectiveness as electrical insulators or are not commonly used today in standard electrical wiring. For instance, wood, metal, and glass are not effective insulators for electrical wires, while materials like cotton and silk, though they were used historically, lack the necessary electrical insulation properties for modern applications. Similarly, paper and vinyl may provide some insulation, but they do not match the performance levels of the materials listed in the correct answer.