A weight mg is suspended from the middle of a rope whose ends are at the same level. The rope is no longer horizontal. What is the minimum tension required to completely straighten the rope is

Explanation

From the diagram
`2T sin theta = mg`
`T = (mg)/(2 sin theta)`
The rope will be straight when `theta = 0`
`T = (mg)/(2 sin 0^(@)) = alpha`
The tension required to completely straighten the rope is infinity.