What is meant by the term back emf?

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Multiple Choice

What is meant by the term back emf?

Back emf is the voltage generated in a coil or motor that acts to oppose the voltage you’re applying. This self-induced voltage arises because a changing current in an inductor creates a magnetic field that induces a new voltage with opposite polarity (Lenz’s law). In a DC motor, as the rotor spins, the machine itself generates a voltage that opposes the supply, and this opposing voltage grows with speed, reducing the net current and helping regulate how the motor behaves. It’s a voltage phenomenon, not a current, and it isn’t a fixed fraction of the applied EMF.

Back emf is the voltage generated in a coil or motor that acts to oppose the voltage you’re applying. This self-induced voltage arises because a changing current in an inductor creates a magnetic field that induces a new voltage with opposite polarity (Lenz’s law). In a DC motor, as the rotor spins, the machine itself generates a voltage that opposes the supply, and this opposing voltage grows with speed, reducing the net current and helping regulate how the motor behaves. It’s a voltage phenomenon, not a current, and it isn’t a fixed fraction of the applied EMF.

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