Question

In steel, the young’s modulus and the strain at the breaking point are $2\times {10}^{11}N/m^2$ and $0.15$, respectively. The stress at the break point for steel is

• A. $1.33\times {10}^{-12}N/m^2$
• B. $1.33\times {10}^{11}N/m^2$
  
• C. $7.5\times {10}^{-3}N/m^2$
• D. $3.0\times {10}^{10}N/m^2$

Answer 1

The correct option is D $3.0\times {10}^{10}N/m^2$

Given,
Young’s modulus
$Y=2\times {10}^{11}N/m^2$
$\text{strain}=0.15$
Using Hook’s law,
$\text{stress}=\text{Young modulus}\times \text{starin}$
$\text{stress}=2\times {10}^{11}\times 0.15$
$\text{stress}=3\times {10}^{10}N/m^2$