Question

A wire elongates by $1.0\text{mm}$ when a load $W$ is hanged from it. If this wire goes over a pulley, and two weights W each are hung at the two ends, the elongation of the wire will be

• A. $0.5\text{mm}$
• B. $1.0\text{mm}$
• C. $2.0\text{mm}$
• D. $4.0\text{mm}$

Answer 1

The correct option is B $1.0\text{mm}$


$\Delta L=\frac{Fl}{AY}$
In both the cases all four quantities are same , extention is same for both cases which is $1mm$