Previous Year Question

Correct answer: A — Galvanized for corrosion resistance

Construction of an ACSR conductor

ACSR means Aluminium Conductor Steel Reinforced. It consists of aluminium strands arranged around a steel core. Aluminium provides high conductivity with relatively low weight and carries most of the line current. The steel core provides tensile strength, allowing the conductor to withstand tension, wind loading and the mechanical demands of long spans.

In conventional ACSR construction, the steel strands are galvanized, meaning they are coated with zinc. The coating separates the steel from moisture and air, reducing rust formation. Zinc also provides sacrificial protection: where a small coating defect exposes steel, the zinc preferentially corrodes and helps protect the steel underneath.

Corrosion protection matters because rust reduces the effective steel cross-section and weakens the conductor’s mechanical support. Thus, the treatment named in the answer preserves the strength and service life of the steel core. It is not primarily intended to increase electrical conductivity. Special aluminium-clad steel-core conductors exist, but the question asks about the typical galvanized-steel ACSR construction.