question_answer

A weight\[\omega \]is suspended from the midpoint of a rope, whose ends are at the same level. In order to make the rope perfectly horizontal, the force applied to each of its ends must be:

A)  less than \[\omega \]

B)  equal to \[\omega \]

C)  equal to \[2\omega \]

D)  infinitely large

Correct Answer: D

Solution :

 For equilibrium of body \[mg=2Tcos\theta \] \[\therefore \] \[T=\frac{mg}{2\cos \theta }\] For the string to be horizontal, \[\theta \to 90{}^\circ \] \[\therefore \] \[T=\frac{mg}{2\cos 90}\Rightarrow T\to \infty \]