How Iron Increases Inductance

[@dalenassar9152]

At about timestamp 10:20 ...this reminds me of the old backstage light-dimming systems (19ty century or so) where there were huge coils in series with the AC lamps...they would push iron rods in and out of the coils to dim and brighten, respectfully, the stage lighting... THANKS FOR THE VIDEO!

[@willemidaho]

Great video, helped me a lot!

[@theavx0670]

Great video, very well explained by a very clever teacher!

[@markn7419]

are there not natural permanent magnets? Also when an audio signal generates a magnetic field across a coil, how does that interact with the permanent magnet & get the speaker to move? Is the RF magnetic field not strong enough to move the speaker on its own?

[@Slovenija_patriot]

Of course there are natural magnets. An example of natural magnet is mineral magnetite, composed of an iron oxide. Basalt, which forms when lava hardens, also contains magnetite, although its magnetic field is weak. Know about speakers. Current through coil generates magnetic field which interacts with magnetic field of permanent magnet and therefore coil moves to align its magnetic field with magnetic field of permanent magnet. That's how we get movement that creates sound.

[@markn7419]

@@Slovenija_patriot thankyou, I guess a smaller or larger magnet will create more or less movement. Also a solenoid is the opposite of this arrangement? its permanent magnet moves instead of the coil?

[@Slovenija_patriot]

@@markn7419 Yes the force of magnet on a coil depends on how strong the magnet is and how big the current through coil is. It also depends on length of the wire inside magnetic field (the more turns the coil has the bigger the force). How loud the sound is depends on the current flowing through the coil which changes to create specific sounds. Yes in solenoid coil is stationary and the magnet moves. You can either have magnet moving and coil stationary or vice versa the effect is the same.

[@dalenassar9152]

BTW Can an air core inductor saturate??

[@Slovenija_patriot]

No air can not saturate like feromagnetic materials but it has low magnetic permeability. This makes air core inductors suitable for applications where high linearity and minimal distortion are required. Saturation accures in some materials like for example iron when increasing magnetic field strength does not increase magnetic flux density.