# Can there be any change in angular velocity without internal torque if angular momentum is to be conserved?

Also, why is angular momentum defined only for one body but linear momentum for a system of bodies?

Coming back to my first question, angular momentum is conserved when no external torque acts on it. However, for a change in angular velocity, we need change in acceleration, which implies the need for torque. This torque can't be external if L is to be conserved. Is it then the internal torque? Can the velocity change without ANY torque?