What is the voltage induced into the armature of a DC motor commonly referred to as?

The voltage induced into the armature of a DC motor is commonly referred to as counter-emf, which stands for counter-electromotive force. This voltage is generated as a result of the motor's rotation within a magnetic field, opposing the supply voltage being applied to the motor's armature.

When the armature spins, it cuts through magnetic lines of flux, which induces a voltage in the opposite direction of the applied voltage according to Faraday's law of electromagnetic induction. This induced voltage effectively reduces the overall voltage that drives the motor, influencing its speed and torque characteristics.

Understanding counter-emf is crucial because it contributes to the regulation of motor speed and helps prevent overheating by limiting excess current flow when the motor is under load. Thus, recognizing the term "counter-emf" is essential for anyone working with DC motors, as it encapsulates the fundamental behavior of induced voltage in these systems.