Question

A wire of length $L$ and area of cross-section $A$, is stretched by a load. The elongation produced in the wire is $l$. If $Y$ is the Young's modulus of the material of the wire, then the force constant of the wire is :

• A. $\frac{YL}{A}$
• B. $\frac{Yl}{A}$
• C. $\frac{YA}{L}$
• D. $\frac{YA}{l}$

Answer 1

Answer: (C)

$\frac{YA}{L}$

According to the definition of Young's modulus
$Y=\frac{F/A}{l/L}\therefore F=\frac{YAl}{L}$
Force constant $=\frac{F}{l}=\frac{YA}{L}$