**Young’s Modulus of Elasticity:**

It is the ratio of stress to strain. The stress and strain can be the factors of both compression and tension.It means Young’s Modulus of Elasticity can also be explained as the ratio of compression stress to compression strain or the ratio of tension stress to tension strain. It is denoted by E.

Mathematically,

E = σ/ε

**Shear Modulus of Elasticity:**

The ratio of shear stress to shear strain is known as Shear Modulus of Elasticity. It can be denoted by C or G. It is also known as Modulus of Rigidity.

**Bulk Modulus:**

The ratio of applied pressure to the volumetric strain is known as bulk modulus of elasticity. It can be denoted by K.

**Relation between Elastic Constants:**

**Poison’s Ratio:**

It is the ratio of lateral strain to linear strain. It is represented by μ