Define modulus of elasticity, stress, strain and Poisson's ratio.

Explanation

1. Stress : Restoring force acting on unit area
is called stress.
`therefore"stress"=("Force")/("Area")=(F)/(A)` ,
Unit : `N//m^(2) (or)` pasacal ,
Dimensional formula : `ML^(-1)T^(-2).`
2. Strain : The change in dimension per unit
original dimension of a body is called
strain.
`therefore"stress"=("elongation")/("original lenth")=(e)/(l)`
It is ratio, so no units and dimensional
formula.
3. Modulus of elasticity :
`therefore` Frome Hooke.s Law Stress `prop` Strain or
`("Stress")/("Strain")="Constant"(E).`
The ratio of stress to strain is called modulus of elasticity.
Unit : `N//m^(2).`
Dimensional formula : `ML^(-1)T^(-2)`
4. Poisson.s ratio : It is defined as the ratio
of lateral contraction strain to longitudinal
elongation strain.
Poisson.s ratio
`(sigma)=("Lateral contraction strain")/("Longitudinal elongation strain")`
It is a ratio, so no units and dimensional
formula.