Let \(\overrightarrow A\) be a unit vector along the axis of rotation of a purely rotating body and \(\overrightarrow B\) be a unit vector along the velocity of a particle P of the body away from the axis. The value of \(\overrightarrow A.\overrightarrow B\) is:
1. \(1\)
2. \(-1\)
3. \(0\)
4. None of these

A particle moves with a constant velocity parallel to the X-axis. Its angular momentum with respect to the origin:

A thin circular ring of mass \(M\) and radius \(r\) is rotating about its axis with an angular speed \(\omega\). Two particles having mass \(m\) each are now attached at diametrically opposite points. The angular speed of the ring will become:
1. \(\frac{\omega M}{M+m}\)

2. \(\frac{\omega M}{M+2 m}\)

3. \(\frac{\omega(M-2 m)}{M+2 m}\)

4. \(\frac{\omega(M+2 m)}{M}\)

A person sitting firmly over a rotating stool has his arms stretched. If he folds his arms, his angular momentum about the axis of rotation:

A particle moves on a straight line with a uniform velocity. Its angular momentum:

Choose the correct option:

If there is no external force acting on a non-rigid body which of the following quantities must remain constant?