Question

A $3cm$ long copper wire is stretched to increase its length by $0.3cm$, find the lateral strain in the wire, if the Poissons ratio for copper is $0.26$

• A. $0.013$
• B. $0.018$
• C. $0.026$
• D. $0.016$

Answer 1

The correct option is C $0.026$

Given, elongation in $3cm$, wire $=0.3cm$ poisson's ratio $=0.26$

$\begin{array}{cc}\sigma & =\frac{\Delta r/r}{\Delta l/l}\\ & \frac{0126}{1000}\times \frac{013}{3}=\frac{\Delta r}{r}\\ \Rightarrow & \frac{\Delta r}{\gamma }=0.026\end{array}$

The lateral strain in the wire is 0.026