Question

Two uniform rods of equal length but of different masses are rigidly combined to form a $L-$ shaped body, which is then pivoted about $O$ as shown in figure. If combination is in equilibrium then ratio $M/m$ will be

• A. $2$
• B. $3$
• C. $\sqrt{2}$
• D. $\sqrt{3}$

Answer 1

The correct option is D $\sqrt{3}$

In equilibrium, torques of forces $mg$ and $Mg$ about an axis passing through $O$ balance each other.


$mg.\frac{L}{2}\cos {30}^{\circ }=Mg\frac{L}{2}\cos {60}^{\circ }$
$\Rightarrow \frac{M}{m}=\sqrt{3}$