A wire elongates by $\ell$ mm when a load $W$ is hanged from it. If the wire goes over a pulley and two weights $W$ each are hung at the two ends, the elongation of the wire will be (in mm) (1) $\ell/2$ (2) $\ell$ (3) $2\ell$ (4) zero
A wire elongates by $\ell$ mm when a load $W$ is hanged from it. If the wire goes over a pulley and two weights $W$ each are hung at the two ends, the elongation of the wire will be (in mm)\\
(1) $\ell/2$\\
(2) $\ell$\\
(3) $2\ell$\\
(4) zero