Question

A constant force is applied on a uniform elastic string placed over a smooth horizontal surface.

Young's modulus of string is $Y$ and cross section of the string is $S$. The strain produced in

the string in the direction of force is :

• A. $\frac{F_{0}Y}{S}$
• B. $\frac{F_0}{YS}$
• C. $\frac{F_0}{2SY}$
• D. $\frac{F_{0}Y}{2S}$

Answer 1

The correct option is B $\frac{F_0}{YS}$

$\begin{array}{c}\text{Given, Ferce applied}=F\\ \text{Area of cross - section}=S\\ \text{Yeung's medulus of string}=y\\ F=YA\left(\frac{\Delta L}{L}\right)\\ \text{Strain}=\frac{\Delta L}{L}=\frac{F}{YS}\\ \text{Hence, option}B\text{is the correct option}\end{array}$