What constant is used to directly relate strain and stress?

• A. Elastic Modulus
• B. Shear Modulus
• C. Bulk Modulus
• D. Young's Modulus

Answer: (D)

The direct link between stress and strain in a material under uniaxial loading is described by Hooke’s law for a linear-elastic solid: sigma = E * epsilon. Here, E is the constant that quantifies stiffness in tension or compression, known as Young’s modulus. It states how much stress is needed to produce a given amount of axial strain. Other moduli describe different deformations: the shear modulus relates shear stress to shear strain, and the bulk modulus relates hydrostatic pressure to volumetric strain. So, the constant that directly relates strain and stress in this context is Young’s modulus.