Q 11-08-096JEE MainJEE Main 2019 (8 Apr, Shift 1)Easy
A steel wire having a radius of $2.0\ \text{mm}$, carrying a load of $4\ \text{kg}$, is hanging from a ceiling. Given that $g = 3.1\pi\ \text{m s}^{-2}$, what will be the tensile stress that would be developed in the wire?
Answer: (D) $3.1\times10^6\ \text{N m}^{-2}$
$$\text{Stress} = \frac{mg}{\pi r^2} = \frac{4\times3.1\pi}{\pi\times(2\times10^{-3})^2} = \frac{12.4}{4\times10^{-6}} = 3.1\times10^6\ \text{N m}^{-2}$$
Solution by Sreeraj P, M.Sc Physics