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Back EMF
Back EMF Back EMF, or "back electromotive force," is a voltage induced in a conductor when a changing magnetic field is present. This phenomenon plays a cruc...
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Back EMF Back EMF, or "back electromotive force," is a voltage induced in a conductor when a changing magnetic field is present. This phenomenon plays a cruc...
Back EMF, or "back electromotive force," is a voltage induced in a conductor when a changing magnetic field is present. This phenomenon plays a crucial role in the operation of many electrical machines, including DC motors.
How it works:
The rotating magnetic field creates a changing magnetic flux in the stationary conductor.
This induces an electromotive force (EMF) in the conductor, which opposes the change in magnetic flux.
The direction of the induced EMF is determined by the right-hand rule.
The magnitude of the induced EMF is directly proportional to the strength of the magnetic field and the rate of change of flux.
Example:
Imagine a DC motor running with a strong current. As the current flows through the motor coil, the magnetic field created by the rotor induces an electromotive force in the stator windings. This induced EMF opposes the change in rotor position, causing the rotor to rotate.
Additional points:
Back EMF is also known as the "induced electromotive force."
It is a counter-EMF, meaning it opposes the original change in magnetic flux.
Back EMF is a key factor in determining the torque of a DC motor, which is its ability to resist rotational motion