There is no magic without MAGNETISM!
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By: Mehdi Sadaghdar
#Magnetism #Inductors

Hi, do you want thanks to Skillshare for sponsoring this video and helping share knowledge more about them later in the video? Okay? Do you want to do magic? You can try this at home. No, really! I have a one and a half volt battery. I have a white LED here that requires around three volts to turn on, so my battery can't turn it on now I put three of these LEDs in series, which means they need nine volt to turn on the battery can't douche. Now I have a regular transformer wall, adapter not connected anywhere, you can use it as ease or you can tear it apart and pull one coil of winding out either way is fine.

Now the positive of the battery goes to the coil. That goes to the positive of the LEDs and returns to the battery the battery. You still can't do, but now, if I short across the LEDs with a piece of wire and let go BAM, I have nine volt pulses across them and they turn on. And here I can replace the coil with the wall adapter and doing the same thing: it's even brighter deep magic.

I wonder if it can shock me here instead of the LEDs, I put my fingers across the wires and short across my fingers. Yeah I mean I can feel it so there are pulses of high voltage, there's a new way to get shocked. I've shown you before that new media magnets drop like a rock in air, but if you drop them through a roll of aluminum foil, they drop very slowly. But similarly, look.

This frame is also made of aluminum, and my magnet has north and south on the surfaces, and, if I put it on and let go, it goes down slowly magic. You can make a few turns of winding and connect an LED to its end and drop it on a wireless charger and bam magic. You stick a battery on a magnet and short the battery using a piece of wire like this, and it starts churning magic. You connect two parallel: reverse LEDs across a coil and pass a magnet through it and ping pong ping pong ping pong ping pong magic.

Of course, I joke it's, not magic. It's magic! Oh! It's magnetism, stay with me to the end to understand. What's going on stay magnetism is quite simple at noob level, which we strive for here when you have charges moving in a direction you have current and magnetic fields wrap themselves around that path like this going to infinity. These follows one of the right-hand rules where the thumb shows the direction of current, which is the flow of positive charges or reverse of electron flow, and other fingers show the direction of fields wrapping around the wire.

So if the current runs in a loop like this, magnetic fields wrap themselves all around the wire like this, and that's why some metals like iron, have stronger magnetic properties and are called ferromagnetic? It's because this cloud of electron turns around the Aten core in a more defined direction and turns the atom into a tiny magnet but see when the molten iron cools down it. Solidifies and crystallizes into this patchy crystal form with every tiny patch having a random magnetic direction. So all these random directions cancel each other and the iron is neutral. If you bring a strong magnetic field close, you force these to rotate and align with the field which not only magnifies the original field.
It turns the iron into a magnet, but it's like these tiny magnets are stuck on a spring, and if you bring external field close, they try to align themselves and the stronger the field the further they align until they fully align. This is when the magnetic material is saturated, meaning that stronger external field won't make any difference in their magnetism, and when we try to remove the external field, they try to spring back unless too much force has bent them permanently out of shape. So when you have a piece of ferromagnetic material and you connect a magnet to it, it becomes a magnet too, and if your source field is strong enough, you can bend those tiny Springs out of shape and make a more permanent magnet. Of course, heat is the enemy of determinants magnets, because their structure shakes out of alignment and the magnet dies forever there.

So don't overheat, your magnets goodbye love, not everything. Hot is kissable. It was Michael Faraday who was first able to imagine an observed magnetic fields as these invisible lines and then later, with the help of Maxwell and some other scientists. They put together these complex equations to describe electromagnetism talk about this.

I'm supposed to be educated, to be able to use these equations, but just seeing them hurts my brain, learn them at your own risk. But here I'd like you to really feel magnetism in your heart. Observing magnetism is quite simple, like my examples at the beginning, except that magnetism is fake. It's like the shadow of electric fields, and it has something to do with Einstein's theory of relativity.

Don't worry, I'm not going there, especially since I don't know what the hell is going on if you're a professor with clarity on the subject, please help me and put me out of my misery, but for now forget about everything, complex and let's stick to primitive ways. Knowing that the concept of magnetism is correct and makes our calculations very efficient and simplified, so magnetism is like an annoying partner. It resists any change like. Let me just know, leave okay, then give me a kiss what the hell are you doing your animal, the hell? Let me just go: don't leave of sex.

What the clip is trying to say is that in magnetism, according to Lenz law, anything that's created due to magnetism opposes any changes in its creator. You raise current through a wire. It induces changing magnetic fields around the wire that create opposing currents in the wire to reduce the changes in the source current. You change the magnetic fields around the wire and they induce a changing current in the wire that creates opposing magnetic fields to stop the changes in the source field.
You raise current through a wire. They create changing magnetic fields around it that oppose the source. Current those fields wrap around another wire and induce a changing current that create opposing magnetic fields and reducing them so that they can't effectively oppose the source current, so the source current rises again, creating even stronger magnetic fields so that it can maintain the output current. It's an opposition mess, but this feature of magnetic fields is what we use to create.

Inductors and transformers. See. Inductance is based on this property that the induced magnetic fields oppose the changing current by inducing an opposing force called electro-motive force. So every piece of wire has some inductance associated to it, but to increase this effect, we loop a longer piece of wire like this, so that the fields created from each wire wrap around more wires, and this increases the inductance and so the magnetic reluctance against the Change of current the overall magnetic fields around such an inductor, which is also an electromagnet, looks like this, with the direction of the fields following the right-hand rule and from north to south, on the outside of the electromagnet and south to north inside.

So increasing the number of turns increases the magnetic fields and raises the inductance. Also, a larger radius increases the length of wire, and so the inductance and adding a ferromagnetic core like iron, magnifies the magnetic fields and significantly raises the inductance inductance is shown with capital L with unit of Henry named after Henry, we can calculate inductance based on the Coil geometry and core property, which I don't care about, you can use online calculators. So after all this description, what is an inductor good for what an inductor does is that it stores energy in the form of magnetic fields in the space around it. Like.

I said those fields oppose the changes in the source current, so they have energy to do it. It is like an elastic hose if i push water current into it. It expands and a steady flow of current goes out of the other side, but if I suddenly shut down the input current the hose collapses and keeps pushing current out of the other side, so it opposes the sudden change of current at the input and that's why They say a capacitor blocks DC, but an inductor blocks AC, which is inaccurate as hell what's accurate is capacitor blocks DC, but inductor shorts DC. So this is important in my previous electro boom, 101 episode.

I told you that capacitors store energy in form of electric fields and oppose the change of voltage. Now inductors store energy as magnetic fields and oppose the change of current. Don't forget that and here's what we end up calculating through complex math for a relation between voltage and current of an inductor. Basically, the voltage across an inductor is equal to its inductance times the rate of current change in time.
If you remember from the capacitor episode, the voltage across a capacitor cannot change instantaneously in no time, because that would mean infinite current through the capacitor. Now the current through an inductor cannot change instantaneously, because that would mean infinite voltage across it and we can't have this in real life, and that explains what happened at the beginning. When I turned on LEDs by a one-and-a-half volt battery, when I shorted across the LEDs, I put a DC voltage across the inductor, so the current through it started to rise only limited by the resistance of the inductor and the battery. When I open the short, though, the current through the inductor couldn't change instantaneously as the magnetic fields were collapsing, so it pushed current into the LEDs and the voltage across them instantaneously jumped to 9 volts.

Also, for example, if the voltage across the inductor changes as a sine wave, then when the voltage is at the peaks, it means that the rate of current change is maximum a positive rate here and a negative rate here, and when the voltage is at zero, it Means that the rate of current change is zero here and here so the inductor current wave looks like this always lagging behind the voltage by 90 degrees. Unlike a capacitor current that always leads the voltage by 90 degrees and there we have it enough details for one episode: inductors of beautiful components like Skillshare. The sponsor of this video skill share is a great online learning community, where people with great skills share them with curious and creative people who want to learn something new or brush up on their knowledge, but wait using my link in the description. The first 500 people get two months free trial of Skillshare premium, which is more than enough to take many classes and get your feet wet.

There are tons of classes on arts, crafts, productivity, film and video production, music, photography and much more. You can take them at your own convenience for as low as $ 10 a month on a one-year subscription after your free trial. I finally switch to Adobe Premiere and After Effects to improve my video quality thanks classes like the one by Jordi Banda put on Premiere Pro, I started smoother and picked up some good tricks. I'm sure you can find something good to help you out to use my link and thank you for watching.

10 thoughts on “Magic of Magnetism & Inductors (ElectroBOOM101-007)”
  1. Avataaar/Circle Created with python_avatars Velmurugan R says:

    youre a god..why you ask?..well you makes the people happy, who enriches human life(by giving knowledge ), does the impossible things(making electronics a fun) and always inspires the followers…(except for the fact that you use bleep a lot…) 😂😂😂 worshipping you my lovable god

  2. Avataaar/Circle Created with python_avatars Samar P. Singh bme says:

    गुरुजी हों तो आप जैसे
    Teacher should be like you…:Cool,friendly,sea of knowledge
    sir why are you not in IIT please sir come india we need you type of Legend

  3. Avataaar/Circle Created with python_avatars SuperHamSniper says:

    I have to try and forget alot of this video or just like not ever think about it since it confused me alot just making my knowledge on this worse.

  4. Avataaar/Circle Created with python_avatars SuperHamSniper says:

    what would happen if you instead of letting the current pass through the diode lights instead just broke the loop, where would the energy stored in the magnetic field even go

  5. Avataaar/Circle Created with python_avatars SuperHamSniper says:

    is the right hand rule only applicable with the creation of magnetic fields?

    because otherwise it would be very confusing and very weird that the magnetic field created by a current creates an opposite current against the right hand rule, this is just confusing my sense of magnetic forces right now and it would be great if i could get an answer on it if there isnt one in the video, so i dont have to waste alot of energy on trying to fix my broken view of how magnetic fields work.

  6. Avataaar/Circle Created with python_avatars SuperHamSniper says:

    wait, does the right hand rule only count when its about something creating magnetic fields? because then why would the created magnetic field oppose the current that it created if its supposed to follow the right hand rule?

  7. Avataaar/Circle Created with python_avatars SuperHamSniper says:

    wait, then, hold on, very important question,

    an elektromagnetic field induces an eddie current that then creates its own opposing magnetic field, right?
    but according to the right hand rule, the eddie current's magnetic field shouldnt be opposing but it is, so whats that about, why is the field opposing?

  8. Avataaar/Circle Created with python_avatars 2DragonFreak says:

    F***ing kidding me? Did research about joule thiefs for like 2 days now and was thinking "let's check Electroboom, before building my first inductor" and booooom: crude joule thief in the first minute

  9. Avataaar/Circle Created with python_avatars Derik says:

    Mehdi, for me personally you do a phenomenal job with explanation on your channel! Years ago I watched Afrotechmods (a favorite of mine). You, BigClive, & few others have truly helped me as a hobbyist. Thank you!

  10. Avataaar/Circle Created with python_avatars Razar Campbell says:

    @ Electroboom
    You can also magnetise an iron rod by banging it repeatedly on a hard surface (a rock/ concrete/ etc)…
    It's not overly efficient but it can magnetise any ferromagnetic metals.
    Also, I suppose, if you cool a ferromagnetic metal from a liquid state to a solid, all while exposing it to a reasonably high magnetic field, the resulting metal will be magnetic.

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