Why is it important that the current in the coil of a motor changes with every revolution?

The current in the coil of a motor changes with every revolution to ensure continuous rotation and efficient operation. This change in current direction generates a magnetic field that interacts with the motor's permanent magnets or stator, producing torque. If the current did not change, the motor would stall as the magnetic fields would align and no longer produce the necessary rotational force. This principle is fundamental to the operation of electric motors, enabling smooth and sustained motion.