A hard material typically exhibits which characteristic?

• A. Exhibits a high modulus of elasticity
• B. Yields greatly before breaking
• C. Does not exhibit high modulus of elasticity
• D. Does not yield greatly before breaking

Answer: (A)

A hard material is characterized by its ability to withstand deformation and resist wear, which is closely related to its mechanical properties. The modulus of elasticity is a measure of a material's stiffness, indicating how much it will deform under stress. A high modulus of elasticity signifies that the material is rigid and does not deform easily under applied forces, making it suitable for applications requiring strength and durability.

In contrast, yielding greatly before breaking typically describes ductile materials, which can absorb significant energy before fracture, whereas hard materials tend to fracture more brittlely without much plastic deformation. Therefore, hard materials do not usually exhibit significant yielding, aligning with their characteristic of having a high modulus of elasticity. This means they resist deformation effectively and can maintain their shape and size under stress, which is an essential property for many engineering applications.