The pulleys and the string shown in the figure are smooth and of negligible mass. For the system to remain in equilibrium angle $\theta$ should be
Answer & explanation
Correct answer: option 3
For mass m to be in equilibrium tension should be T = mg
vertical component of this tension should balance weight of mass $\sqrt 2 m$.
⇒ 2Tcos$\theta$ = $\sqrt 2 mg$
⇒ 2mg cos$\theta$ = $\sqrt 2 mg$
⇒ $cos\theta = \frac{1}{\sqrt 2}$
$\theta = 45^\circ$