Tensile Modulus , Modulus of Elasticity, Young modulus is defined as the stress required to cause a unit strain in the material. It is the ratio of linear stress to linear strain. In other words Young modulus is used to measure the elasticity of an elastic material. It corresponds to linear or tensile strain.
Let a wire of initial length L and cross-sectional area ‘ A’, undergo an extension l, when a stretching force ‘F’, is applied in the direction of its length.
Young’s modulus (modulus of elasticity) is given by-
Formula of Young’s modulus = Linear Stress / Linear Strain.
Longitudinal or linear stress = Force / Area. = F/A
Longitudinal or linear strain = Change in length / Original length = l / L
Using the above formula we get,
The unit for Young’s modulus is newton metre-2 with symbol N m-2.
The single term unit normally used for Young’s modulus is ‘pascal’ with symbol ‘Pa’.