# Can magnetic flux be surpressed or added to?

1. Sep 15, 2009

### mmalf_mi

I am studying inductance. Can the core flux be added to or suppressed by the secondary of a transformer. I have been taught that there is only one core flux field. I understand that flux can be squeezed or attracted, I am I correct in stating; a primary current is opposed by a back current because of Lenz Law. Lines of flux cutting the primary and secondary wires causing an opposite current in both primary and secondary. Aside from core magnetizing currents and eddy currents the primary current would be 0. This secondary current has a back current (Lenz Law). This secondary back current opposes the primary back current in the core. With less back current in the primary, the primary current will increase until it causes an equal back current.

2. Sep 17, 2009

### turin

You are basically correct (though I'm not sure I understand your terminology 100%). Lenz's Law, yes. Transformers are characterized by mutual inductance, which tells you how emf is induced in each winding by the current in each winding (four relationships in total). So, for instance, the current in the primary induces a back emf in the primary and also an emf in the secondary.