A rod of length $L$ can rotate about end $0 .$ What is the work done if the rod is rotated by $180°$

Two uniform rods of equal length but different masses are rigidly joined to form an $L$ -  shaped body, which is then pivoted as shown in figure. If the given configuration in equilibrium then ratio  $\frac{\mathit{M}}{\mathit{m}}$ will be :-

A uniform rod of length $l$ and mass $m$ is free to rotate in a vertical plane about $A$. The rod initially in a horizontal position is released. The initial angular acceleration of the rod is (Moment of inertia of the rod about $A$ is $\frac{M{l}^2}{3}$)

Assertion : If the momentum of a particle is constant, then its angular momentum will also be constant

Reason : When net external force on an object is zero, then external torque on the object will also be zero.

A particle is moving uniformly along a straight line as shown in the figure. During the motion of the particle from $A$ to $B$, the angular momentum of the particle about ${}^{\text{'}}O^{\text{'}}$