Which materials are commonly used as insulators in electrical applications?

In electrical applications, materials used as insulators are critical for preventing unintended current flow and ensuring safety. The choice of rubber, glass, and plastic as insulators is well-founded due to their specific properties.

Rubber is highly flexible and can withstand a wide range of temperatures, making it an excellent insulator. It is often used in cables and wiring insulation. Glass has a high dielectric strength, which means it can resist electric current very effectively, making it suitable for various electrical applications, including insulators in high-voltage power lines. Plastic materials, especially in the form of PVC or polyethylene, are widely utilized for insulating various electrical components due to their durability, resistance to moisture, and low cost.

These materials not only offer effective insulative properties but also possess mechanical strength and resistance to environmental factors, enhancing their suitability in electrical applications. In contrast, the other materials listed in the other choices do not provide adequate insulation for electrical applications, as they either conduct electricity or lack the physical properties necessary for effective insulation.