Question

The breaking stress of aluminium is $7.5\times {10}^7$ $N{m}^{-2}$. The greatest length of aluminium wire that can hang vertically without breaking is
(Density of aluminium is $2.7\times {10}^3$ kg $m^{-3}$)

• A. $283\times {10}^{3}m$
• B. $28.3\times {10}^{3}m$
• C. $2.83\times {10}^{3}m$
• D. $0.283\times {10}^{3}m$

Answer 1

The correct option is C $2.83\times {10}^{3}m$

$\begin{array}{c}weget\\ 2.7\times {10}^3\times l\times g=7.5\times {10}^7\\ \Rightarrow l=\frac{7.5}{2.7}\times {10}^3\\ =2.83\times {10}^{3}m\end{array}$

Hence, option $C$ is the required answer.