A rod PQ of mass M and length L is hinged at end P. The rod is kept horizontal by a massless string tied to point Q as shown in figure. When string is cut, the initial angular acceleration of the rod is :

\(\frac{2 g}{3 L}\) \(\frac{3 g}{2 L}\) \(\frac{g}{L}\) \(\frac{2g}{L}\)

\(\frac{3 g}{2 L}\)

\(Torque : \tau = \vec{r} × \vec{F}\) Also, \(\tau = I\alpha\) For rod, I = \(\frac{ML^2}{3}\) ⇒Mg\(\frac{L}{2} = (\frac{ML^2}{3})\) ⇒\(\alpha = \frac{3g}{2l}\)