# inductor VS mutual inductance frequency voltage drop

#### relicmarks

Joined Oct 13, 2006
355
If you put a function generator as a input to a inductor , 12 volt AC from 10khz , the 12 volts AC stays the same

*When your lower the frequency the 12volts will "drop down at a lower voltage"

If you put a function generator as a input to a mutual indutance ( transformer) , 12 AC from 10K , the 12 volts AC stays the same

*When i lower the frequency the 12 volts "STAYS THE SAME "

1.) I don't get why the voltage drops with frequency with a inductor but not with mutual indutance?

2.) Mutual inductance must not have reactance?

3.) Its the reactance in the inductor that causes the voltage to drop with frequency

#### mik3

Joined Feb 4, 2008
4,843
This happens because as you make the frequency lower the reactance of the inductor reduces and more current is drawn out of the generator. Because the output current increases the voltage drop across the internal impedance of the generator increases and thus the output voltage decreases.
In the case of a transformer, if you connect it on the primary winding, the voltage does not fall because this winding has a relatively large resistance which limits the current drawn from the generator to values the generator can regulate the output voltage (if it is regulated). if you try this when the generator is connected to the secondary of the transformer you will observe the same result as with the inductor.