As there is no external torque acting on it, its angular
momentum remains constant. This is according to the law of
conservation of angular momentum
View page
Conservation of angular momentum.
View page
it works on the basis of conservation of linear momentum
View page
It is conservation of [angular] momentum.
View page
There are several conservation laws in nature: conservation of
mass, conservation of energy, of momentum, of angular momentum, of
electric charge, and others.