Reverse electromagnetic force, often referred to as back EMF, occurs in coils or transformers when an alternating current (AC) is applied. The primary coil generates an AC current that creates a magnetic flux, which induces a current in the secondary coil. This induced current generates its own magnetic flux that opposes the primary flux, resulting in a reduction of input impedance in the primary. This phenomenon is crucial for understanding how transformers operate and reflects the load impedance back to the primary side. The explanation clarifies the concept effectively.
