Cable with impregnated-paper insulation typically has what kind of sheath?

Cable with impregnated-paper insulation typically uses a lead sheath for several reasons related to the properties of the materials involved. Lead is an excellent barrier to moisture, effectively protecting the impregnated-paper insulation from environmental factors that can cause deterioration. This preservation of the insulation ensures optimal performance and longevity of the cable.

Additionally, lead provides good electrical shielding, which is vital for minimizing interference in electrical transmission. Its density and durability make it suitable in applications where cables might be subjected to rough conditions, thus enhancing safety and reliability.

Plastic, rubber, and metal sheaths do not offer the same level of moisture protection or durability that lead does, making lead the preferred choice for cables with impregnated-paper insulation.