question_answer

The pulleys and strings shown in the figure are smooth and of negligible mass. For the system to remain in equilibrium, the angle \[\theta \]should be                                [IIT-JEE 2001]

A) \[{{0}^{o}}\]           

B) \[{{30}^{o}}\]

C) \[{{45}^{o}}\]         

D) \[{{60}^{o}}\]

Correct Answer: C

Solution :

    From the figure for the equilibrium of the system \[2T\cos \theta =\sqrt{2}mg\] Þ \[\cos \theta =\frac{1}{\sqrt{2}}\] Þ \[\theta =45{}^\circ \]