Which type of medium-voltage insulated conductor is characterized by corrugated or concentric neutral designs?

The characteristic feature of a concentric neutral design is that it consists of layers of conductors arranged in such a way that the neutral conductor is formed by the outer layer surrounding the inner phase conductors. This design helps in managing electrical fields and provides shielding, which enhances safety and reduces electromagnetic interference. Concentric neutral cables are often used in medium-voltage applications because they allow for more efficient grounding and fault current management.

The corrugated features in these designs serve to both protect the conductors within and facilitate better thermal dissipation. This type of construction is increasingly favored in underground installations and applications where enhanced durability and reliability are required.

In contrast, other types of insulated conductors mentioned, such as tape, cable, and metal-clad, do not specifically describe the arrangement or design of their neutral components as being concentric or corrugated, thus leading to their exclusion as the best answer to this particular question.