Relation Between Volumetric Strain, Lateral Strain And Poisson’s Ratio - Practice Questions & MCQ

Let us long rod have a length L and radius 'r', then volume of this rod = 

Now, Differentiating both the sides of , we get

Now, dividing both the sides by volume of rod , i.e., , we get , 

So we can say that,

Volumetric strain = Longitudinal strain + 2(Lateral strain)

Also,  can be written as, 

                              This is because , 

Special case -

•  When , then . It means that the substance is incompressible, so there is no change in volume.

• If a material having = 0, it means lateral strain is zero. So, when a substance is stretched its length increases without any decrease in diameter. For example - cork has . Also, in this case change in volume is maximum.