JEE Main Physics question

Physics Systems of Particles and Rotational Motion JEE Main

The angular momentum of a system of particles is conserved

(A)When no external force acts upon the system
(B)When no external torque acts on the systemCorrect
(C)When no external impulse acts upon the system
(D)When axis of rotation remains same

Answer: (B)

Solution

By definition, angular momentum is conserved precisely when the net external torque on the system is zero.

Question ID VK-159027