If the volume of a wire remains constant when subjected to tensile stress, the value of poisson's ratio of material of the wire is

Options

A. `+0.50`
B. `-0.50`
C. `+0.25`
D. `-0.25`

Answer

B

Explanation

here `V=(piD^2)/(4)xxL`
As `V` does not change, `(dV)/(dD)=0`
or `(dV)/(dD)=2DdD`,`L+D^2dL=0`
or `(2DL)/(D)=-D^2dL`
or `((dD)/(D))/((dL)/(L))=-(1)/(2)=-0.5`
Correct choice is (b).