ANS:C - ductile

"Ductile" is a term used to describe materials that can undergo significant plastic deformation before failure. This means that ductile materials are capable of being stretched, bent, or deformed under an applied load without fracturing or breaking apart easily. When a ductile material is subjected to tensile (stretching) forces, it will initially exhibit elastic deformation, where it deforms reversibly under load but returns to its original shape once the load is removed. As the applied load increases, the material eventually reaches its yield point, beyond which it undergoes plastic deformation. In the plastic deformation region, the material undergoes permanent deformation as atomic bonds within the material shift and rearrange, allowing the material to flow and change shape without rupturing. This plastic deformation process continues until the material eventually fails under excessive stress. Ductility is an important mechanical property for many engineering materials, as it allows them to absorb energy and deform plastically before failure, providing warning signs of impending failure and preventing sudden catastrophic fracture. Ductile materials are often used in applications where deformation or shaping is required, such as forming processes in manufacturing, structural components in construction, and components subject to cyclic loading or impact in various industries. Examples of ductile materials include metals such as steel, aluminum, copper, and titanium, as well as certain plastics and polymers with ductile behavior under specific conditions.