Question

If in case $A$, elongation in wire of length $L$ is $\Delta L$, then for the same wire, elongation in case $B$ will be

• A. $4\Delta L$
• B. $2\Delta L$
• C. $\Delta L$
• D. $\frac{\Delta L}{2}$

Answer 1

The correct option is C $\Delta L$

Elongation in the wire is given by $\left(\Delta L\right)=\frac{FL}{AY}$
where $F=$Force applied
$L=$Length of wire
$A=$Area of cross-section
$Y=$Young's modulus of wire


$\because F=$ Tension$\left(T\right)$
and $T=W$
Since, tension in both cases is same and all other parameters $Y,A$ and $L$ are also same.
So, elongation will be same in both cases.