Which cable type is rated at 5000 volts and features helically wrapped paper tapes around the conductor?

The correct choice is the impregnated-paper type of cable, which is specifically designed to handle higher voltage ratings, such as 5000 volts. This type of cable features layers of paper insulation that are impregnated with a special dielectric oil or compound, significantly enhancing their insulating properties. The helically wrapped paper tapes around the conductor serve to provide superior insulation and moisture resistance while allowing for some flexibility, which is important for installations that may require bending or shaping of the cables.

Impregnated-paper cables are commonly used in high voltage applications due to their ability to maintain insulation integrity under high stress and temperature conditions. The wrapping of the paper also helps to withstand radial stresses, ensuring that the cable maintains its shape and performance over time, especially in aerial or underground applications where environmental conditions may vary.

Other cable types, such as cross-linked polyethylene, varnish-cambric, and rubber insulation, have their own characteristic properties and applications, but they do not feature the same construction or voltage ratings as impregnated-paper cables. While they may be suitable for various electrical applications, their insulation techniques and material compositions are different and do not include the helically wrapped paper tapes fundamental to the impregnated-paper cable design.