A DC motor has a terminal voltage of 5V, a motor constant of Ka = 5.2 x 10-3 Vs, and an armature resistance of 500-ohm. Find the stall current, max speed in rotations per minute (RPM), and armature current at a speed of 480.769 radian/s (4591.006 RPM).
What is the relationship (if any) between the armature current at max speed, speed at the stall current, and the armature current at a speed of 480.769 radian/s?