Question

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:

• A. $0^{\circ }$
• B. ${30}^{\circ }$
• C. ${45}^{\circ }$
• D. ${60}^{\circ }$

Answer 1

The correct option is C ${45}^{\circ }$

For equilibrium of $M$ block
$T=Mg$
For equilibrium of $\sqrt{2}\text{M}$ block
$2T\cos \theta =\sqrt{2}\text{Mg}$,
Putting $T=Mg$
$\cos \theta =\frac{1}{\sqrt{2}},\theta ={45}^{\circ }$
$\therefore$ (c)