Moduli Relation Y Eta Sigma — the NEET Physics formula with its derivation, variables, validity constraints and worked solver.
Young-Shear-Poisson Moduli Relation This relationship is valid for isotropic, linear elastic materials under uniaxial stress conditions. Start with the definition of Young's Modulus: Y = axial axial . Use Poisson's ratio ( ) to relate axial strain to lateral strain: lateral = - axial . Define Shear Modulus ( ) based on shear stress and shear strain. Combine the definitions of Y, , and through the generalized Hooke's Law for stress and strain. [-1, 1] The material must be assumed to be linear and isotropic. Confusing this relationship with the bulk modulus formula (K). Assuming the relationship holds for viscoelastic materials or materials under non-linear stress. Incorrectly applying the signs for Poisson's ratio (it must be negative for typical materials).