Question

A steel wire having a radius of $2.0mm$, carrying a load of $4kg$, is hanging from a ceiling. Given that $g=3.1\pi m{s}^{-2}$, what will be the tensile stress that would be developed in the wire?

• A. $4.8\times {10}^{6}N{m}^{-2}$
• B. $5.2\times {10}^{6}N{m}^{-2}$
• C. $6.2\times {10}^{6}N{m}^{-2}$
• D. $3.1\times {10}^{6}N{m}^{-2}$

Answer 1

The correct option is D $3.1\times {10}^{6}N{m}^{-2}$

Tensile stress in wire will be
$=\frac{\text{Tensile force}}{\text{Cross-sectional Area}}$

$=\frac{mg}{\pi R^2}=\frac{4\times 3.1\pi }{\pi \times 4\times {10}^{-6}}N{m}^{-2}=3.1\times {10}^{6}N{m}^{-2}$.