Question

For a given material, the Youngs modulas is $2.4$ times its modulus of rigidity. What is the value of its poissons ratio ?

• A. $0.5$
• B. $0.4$
• C. $0.2$
• D. $0.3$

Answer 1

The correct option is C $0.2$

$\begin{array}{c}\text{Given that,}\\ \text{young's modulus is}2.4\text{times its modulus of rigidity}\\ \text{So, we can write}\\ Y=2\cdot 4G\dots \left(i\right)Y=\text{young's modulus}\\ G=\text{modulus of rigidity}\end{array}$

$\begin{array}{c}Y=2G(1+\sigma )\text{where}\sigma \text{is poission ratio.}\\ \text{we know relation,}\\ \begin{array}{c}2\cdot 4\cdot 6=2\cdot 6^{}(1+\sigma )\\ 1\cdot 2=(1+\sigma )\\ \sigma =0.2\end{array}\end{array}$