What is a key feature of non-metallic sheathed cable?

Non-metallic sheathed cable, commonly known as NM cable or Romex, is designed with a key feature that includes insulation to prevent electrical shock. This insulation surrounds the conductors within the cable, which serves several vital functions: it provides protection from physical damage, ensures safety by reducing the risk of electric shock, and helps to minimize the possibility of short circuits.

The insulation used in non-metallic sheathed cable is typically made from materials like PVC, which is effective at preventing the conduction of electricity through unintended paths. This feature makes NM cable particularly safe for use in residential applications where households require reliable and safe electrical installations.

In terms of the other options, metal durability is not applicable, as non-metallic sheathed cable is designed to be lightweight and flexible rather than metal. It is also not more expensive than many other wiring types and can be more cost-effective, especially in residential settings. Additionally, while non-metallic sheathed cable can be used outdoors in certain applications, it is primarily intended for indoor use, particularly in dry locations.