The angular momentum of a system of particles changes if:

$A$ mass tied to a string is whirled in a horizontal circular path with a constant angular velocity and its angular momentum is $L$. If the string is now halved,keeping the angular velocity the same,then the new angular momentum will be:

Why is the angular momentum perpendicular to the axis,denoted as ${L_ \bot }$,zero in a rotational motion about a fixed axis?

The Earth is assumed to be a sphere of radius $R$ and mass $M$ having a period of rotation $T$. The angular momentum of the Earth about its axis of rotation is

The angular momentum of a body is the product of which of the following?

Consider a body,shown in the figure,consisting of two identical balls,each of mass $M$,connected by a light rigid rod of length $L$. If an impulse $J = Mv$ is imparted to the body at one of its ends,what would be its angular velocity?