I'm trying to understand transformers and am reading this site: Mutual inductance and basic operation
I am a little confused about how to reason about the voltages involved in a transformer.
Assume that the number of windings in both coils of a transformer are the same.
Assume at time 0, a voltage of V1 starts increasing from 0 to some positive value.
This change in current creates a back emf, which as I understand studying so many years ago, is a voltage that opposes the current that created it (Lenz's law).
If this back emf is being created by the change in flux of the magnetic field, then if the second loop of the transformer is wound in the same direction as the first loop( because this determines the direction of the magnetic field) I would expect that the back emf voltage from the applied voltage in the first loop should also be induced in the 2nd loop of the transformer.
according to the linked website, the voltage induced in the second loop should be of the same magnitude as the applied voltage.
But I remember being taught in school that when current is run through a way, the induced emf from self-inductance is a voltage in the opposite direction with a smaller magnitude.
Is this incorrect? perhaps my memory is wrong?
According to the website, with the same the # of windings on both sides of a transformer the voltage through the 2nd side of the transformer is the same as the applied voltage.
But if the back emf from self-induction is a smaller voltage then I would expect the induced voltage in the 2nd loop to be a smaller voltage.
Is my memory of the magnitude of the back emf wrong?