Q1: Magnesium addition to cast iron increases its

ANS:C - ductility and strength in tension.

Ductility: Ductility is a mechanical property that describes the ability of a material to deform plastically before fracturing under tensile loading. In simpler terms, it refers to the extent to which a material can be stretched or elongated without breaking. Materials with high ductility can undergo significant plastic deformation, allowing them to be drawn into wires or formed into various shapes without failure.

1. For example, a highly ductile material like copper can be drawn into thin wires, while a material with low ductility, like cast iron, would fracture under similar conditions.
2. Strength in Tension: Strength in tension refers to the ability of a material to withstand tensile forces without fracturing or breaking. When a material is subjected to tensile loading, it experiences internal forces that tend to pull its molecules apart. The strength of the material determines its resistance to these forces. There are different types of strength that can be considered in tension, such as:
   • Yield strength: The point at which the material begins to deform plastically under tensile loading.
   • Ultimate tensile strength (UTS): The maximum stress a material can withstand before fracturing.
   • Fracture strength: The stress at which the material actually fractures.
   Improving strength in tension typically involves enhancing the material's resistance to deformation or fracture under tensile loading. This can be achieved through various means such as alloying, heat treatment, or changing the material's microstructure.

In summary, ductility describes a material's ability to deform plastically without fracturing, while strength in tension refers to its ability to withstand tensile forces without breaking. Magnesium addition to cast iron can increase both its ductility (allowing it to deform more before fracture) and its strength in tension (resisting fracture under tensile loading).