Define Young's modulus, bulk modulus and shear modulus.

Explanation

Young.s modulus (y) : With in the elastic limit, the ratio of longitudinal stress to longitudinal strain is called young.s modulus.
`y=("Longitudinal Stress")/("Longitudinal Strain")=((F)/(A))/((e)/(L))`
`y=(FL)/(A.e)`
S.I. units`toN//m^(2)` (or) Pascal
Bulk modulus (B) : With in the elastic limit, it is defined as the ratio of Bulk stress to Bulk strain
`B=("Bulk Stress")/("Bulk Strain")`
`B=((F)/(A))/((-DeltaV)/(V))=(-PV)/(DeltaV)` (`because-ve` sign indicates volume decreases)
S.I. units `toN//m^(2)` (or) Pascal.
Rigidity modulus (G) : With in the elastic limit, it is defined as the ratio of shearing stress to shearing strain.
`G=("Shearing Stress")/("Shearing Strain")`
`G=((F)/(A))/(theta)=(F)/(Atheta)`
S.I. units`toN//m^(2)` (or) Pascal.