The inductance of a coil is very much higher if it has an iron core.
Four times the inductance will tune to double these wave-lengths.
But what would happen if we should decrease the capacity and increase the inductance?
The first is that the inductance will be larger if the turns are large circles.
Suppose you wind two inductance coils and connect them in series.
It was the condenser and inductance which you studied in connection with Fig. 36.
We can either adjust the capacity as we just did, or we can adjust the inductance.
The lamps are stabilized by resistance and inductance coils.
We used a double metallic circuit so as to avoid the effects of inductance from our electric lighting circuit.
I have told you all except one of the ways in which we can affect the inductance of a circuit.