Question

Define young's modulus for a material. A wire of length L and area of cross section A is stretched by a force of magnitude F. It is found that the length of the wife is increased by delta l .
Find:
1. longitudnal stress
2.longitudnal strain
3.young's modulus

Answer 1

Young's Modulus :
 Within in the elastic limit, The ratio between longitudinal stresses to longitudinal strain is called as Young's Modulus.
Young's Modulus (Y)=Longitudinal Stress/Longitudinal Strain
Stress is defined as restoring force per unit area .
Stress=F/A
There are two types of Stress:
1. Longitudinal Stress 2. Shearing Stress 3. Bulk Stress
Longitudinal Stress :
If the determining Force causes a change in length of a body, then the restoring force per unit area is called Longitudinal or linear or tensile stress.
Longitudinal Stress=Restoring Force/area=F/A
Strain is called as change produced per unit dimension.
Types of Strain:
1. longitudinal Strain 2. Shearing Strain 3. Bulk Strain
Longitudinal Strain:
when deformation force is applied on a body along its length, then the ratio of change in length of the body to its original length is called longitudinal
longitudinal strain=change in length/original length=Δ L/L