When the supply terminal of a DC shunt motor are interchanged
A. The direction of rotation will reverse.
B. The motor will run at its normal speed in the same direction as before.
C. The motor will stop.
D. The motor will run much faster in the same direction.
Answer: D
Share your understanding of this question with the correct explanation.
When the supply terminals of a DC shunt motor are interchanged, the motor will run much faster in the same direction.
The direction of rotation of a DC motor is determined by the polarity of the applied voltage. By interchanging the supply terminals, the polarity of the applied voltage is reversed. However, in a DC shunt motor, the field winding and armature winding are connected in parallel, which means they share the same voltage polarity.
When the supply terminals are interchanged, the voltage across both the field winding and armature winding reverses. This causes a change in the motor’s operating conditions, including the armature current and the counter electromotive force (EMF) produced by the armature.
As a result, the motor will run much faster in the same direction. The change in voltage polarity alters the balance between the armature current and the counter EMF, leading to an increase in the speed of the motor.
Therefore, the correct answer is D: The motor will run much faster in the same direction.