What is the significance of coating electric wires with substances like polyvinylchloride (PVC) or rubber-like materials, and what is the term for metals that produce a sound when striking a hard surface?

Coating electric wires with substances like polyvinylchloride (PVC) or rubber-like materials serves as insulation, preventing electric shocks and ensuring safety. These coatings provide a barrier, protecting against exposure to electric currents. The term for metals that produce a sound when striking a hard surface is “sonorous.” Sonorous metals, such as copper and silver, emit a characteristic ringing sound due to their high density and ability to vibrate when struck. This property makes them valuable for musical instruments, bells, and other applications where a clear and resonant sound is desired.