Question

Young's modulus of perfectly rigid body material is:

• A. Infinite
• B. Zero
• C. $10\times {10}^{10}N/m^2$
• D. $1\times {10}^{10}N/m^2$

Answer 1

Answer: (A)

Infinite

From Hooke's law, Young modulus $Y=\frac{Stress}{Strain}$

The $Strain$ produced in a perfectly rigid body is zero i.e $Strain=0$

$\therefore$ $Y=\frac{Stress}{0}$ $⟹Y=\infty$

Thus the Young's modulus of perfectly rigid body material is infinite.