In construction work, the alloy duralumin is used rather than pure Aluminium because:(A) duralumin is light and strong(B) duralumin is corrosion resistant(C) duralumin has high tensile strength(D) All of these.

The correct answer is (D) All of these.

Duralumin is an alloy composed primarily of aluminum, with copper, manganese, and magnesium as additional elements. It is widely used in construction work due to its favorable properties. Here's why:

(A) Duralumin is light and strong: Duralumin retains the lightweight nature of aluminum while offering enhanced strength. This combination makes it a suitable choice for construction applications where strength and weight considerations are important.

(B) Duralumin is corrosion resistant: The addition of copper and other elements to aluminum in duralumin enhances its corrosion resistance. This property makes it well-suited for construction projects, as it can withstand exposure to various environmental conditions and moisture without significant corrosion damage.

(C) Duralumin has high tensile strength: The alloying elements in duralumin contribute to its increased tensile strength compared to pure aluminum. Tensile strength refers to the ability of a material to withstand pulling forces without breaking or deforming. This high tensile strength makes duralumin a valuable material in construction, where structural integrity is crucial.

Therefore, considering all these factors, duralumin is preferred over pure aluminum in construction work.