Question 414Electricity & Electronics - Assistant Engineer

The correct answer is B) The direction of rotation of the armature will remain the same. When both the polarity of the field poles and the direction of current to the brushes of a DC motor are reversed, the magnetic field in the motor is reversed, but the armature will continue to rotate in the same direction. This is because the direction of the mechanical force acting on the armature conductors is determined by the interaction between the magnetic field and the current in the armature, and reversing both the field and the current direction results in no change to the direction of this force, and therefore no change to the direction of rotation. The other options are incorrect because: A) is incorrect as the direction of rotation will remain the same; C) is incorrect as the motor will still start, just rotating in the same direction; and D) is incorrect as the field pole windings will not become overheated due to the reversal of both the field and current direction.