Question

A weight $mg$ is suspended from the middle of a rope whose ends are at same level. If the rope is no longer horizontal, the minimum tension required to completely straighten the rope will be

• A. $mg$
• B. $\sqrt{mg}$
• C. Infinite
• D. Zero

Answer 1

The correct option is C Infinite

The given situation can be shown as from figure
$2T\sin \theta =mg$
or $T=\frac{mg}{2\sin \theta }$
when rope is straight, $\theta =0^{\circ }$
$\therefore T=\frac{mg}{2\sin 0}=\infty$ (infinite).