A structural steel rod has a radius r(=10 mm) and a length l(=1 m). When a force F(= 100 kN) is applied, it stretches it along its length. Young's modulus of elasticity of the structural steel is `2.0xx10^(11) Nm^(-2)`.
What is the stress produced ?

Options

A. `1.59xx10^(9)` Pa
B. `3.18xx10^(9)` Pa
C. `3.18xx10^(8)` Pa
D. `1.59xx10^(8)` Pa

Answer

C

Explanation

Here, `r=10 mm = 10^(-2) m , l= 1 m` ,
`F=100 kN =100xx1000 N =10^(5) N`
Stress `=(F)/(pi r^(2)) =((10^(5))N)/((22//7) (10^(-2))^(2)m^(2))`
`=3.18xx10^(8) Nm^(-2)`