Magnetic field created by a current carrying wire | Physics | Khan Academy

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  • Опубліковано 16 січ 2025

КОМЕНТАРІ • 196

  • @leothelion634
    @leothelion634 13 років тому +39

    this guy should start a new series: How to draw hands

  • @MrDavidBradfield
    @MrDavidBradfield 12 років тому +27

    I love how you WANT to make us understand, it feels like my teachers just want to get their job done, as if its tedious

    • @showshowtomakefreeenergyge2426
      @showshowtomakefreeenergyge2426 2 роки тому

      Quantum mechanics has attempted to explained the phenomena of magnetism by excluding Ether from the scientific community. However, many scientists have argued that this exclusion is not justified because quantum mechanics cannot account for the basic principles of electromagnetism. For example, quantum mechanics cannot explain how a current carrying wire creates a magnetic field.

  • @kobuskotze7839
    @kobuskotze7839 7 років тому +12

    If the magnetic field direction sketches explained at 1:50 still doesn't make sense, try to imagine a moving dart. If the pointy end is moving towards you, you only see a dot. If it's moving away, you see the cross from its fins. This obviously applies to current or anything else directed"into" or "out of" the board.

    • @omarsmith6561
      @omarsmith6561 5 років тому

      can you elaborate please
      as in how can you determine the direction of it

    • @showshowtomakefreeenergyge2426
      @showshowtomakefreeenergyge2426 2 роки тому +1

      Quantum mechanics, the theory of the very small, has never been able to explain the phenomena of magnetism. Magnetism is created when a current carrying wire creates a magnetic field. But quantum mechanics doesn't allow for fields that are not controllable by particles. So how do we explain the magnetic field created by wires? The answer lies in the Ether. The Ether is a medium that permeates space and is thought to be responsible for creating and holding together Magnetic Fields.

    • @Altair4611
      @Altair4611 2 роки тому

      You would see the fins regardless of which way it is going

    • @weebmaster9591
      @weebmaster9591 Рік тому

      @@showshowtomakefreeenergyge2426photons are the carriers of the electromagnetic force and the clear answer to your problem. The ether is not required and can be considered synonymous with space

  • @eggyrepublic
    @eggyrepublic 5 років тому +60

    I can't get a hand that good by drawing on paper, and this dude just straight up draws it with a mouse.

  • @Dan-bg5fm
    @Dan-bg5fm 8 років тому +112

    you should quit youtube and be a professional artist . that hand you drew was on point lol

    • @galibkhan2260
      @galibkhan2260 8 років тому +4

      he can quit utube & do a tons of things :p

    • @ani-bv5mq
      @ani-bv5mq 6 років тому

      Dan 😁😁

    • @djtoddles8750
      @djtoddles8750 6 років тому

      Sal Khan is the Picasso of hand drawing

    • @crystal_royal3405
      @crystal_royal3405 5 років тому

      Lmao

    • @PrideofPitchers
      @PrideofPitchers 5 років тому +2

      He was actually a cartoon artist for his town growing up. he says it in another video lol.

  • @seanbullis3364
    @seanbullis3364 11 років тому +30

    "For your highschool physics class..."
    but what about my college physics with vector calc class lol

  • @silenttreatment4459
    @silenttreatment4459 6 років тому +5

    3:05 Soooo cute!!!!

  • @KonesThe
    @KonesThe 9 років тому +30

    Not a native english. Thought I would not keep up with the video, but you actually explain very clear and understanding. Thanks.

    • @heatherbloom5426
      @heatherbloom5426 7 років тому

      KonesThe yeah exactly...if u watch the videos of crashcourse physics u feel a lot of difficulty in understanding but literally hank greens accent is so vivid

    • @student9977
      @student9977 4 роки тому

      @@heatherbloom5426 this isnt Hank greens tho

  • @prathambabaria5834
    @prathambabaria5834 4 роки тому +6

    Such a genuine, honest, and talented individual. I wish everyone in the world was like him.

  • @larad9649
    @larad9649 12 років тому +3

    I have my exam tomorrow and my teacher explained this is the most un-understandable ways!
    you saved my life!
    thank you!

  • @animeshverma6419
    @animeshverma6419 7 років тому +108

    Who else mugging these up at 1.25x speed (it still sounds just fine ) a few hours before exam?😂🔫

  • @Max11551
    @Max11551 16 років тому +2

    Cool. Had this in physics class a couple months ago, now it makes even more sense.

  • @gdogvibes1
    @gdogvibes1 10 років тому +28

    How is he so smart?

  • @RazorFistMusicOuttaTheWorld
    @RazorFistMusicOuttaTheWorld 5 років тому +3

    I love Vector Calculus
    Finding the total fluid force on the hemispherical tank amounted to computing
    a new kind of integral over a surface, or surface integral. As our course develops, we'll see a great need for integrating both functions and vector fields over nice surfaces like the hemispherical tank.
    Because of the complexity and importance of surface integrals, we'll have a whole chapter devoted to them. That same chapter also builds from scratch the Divergence Theorem, one of the most important results of our course.
    In the next unit, we'll use what we learned apprenticing for Mr. Adams at Tanks For All The Fish to begin to understand the depth of this remarkable theorem.

  • @harshpatil2046
    @harshpatil2046 9 років тому +8

    English is not my first language, I find it difficult to talk with people or understand what they say, but you explained it beautifully, and my doubts are cleared now, thank you Khan Academy :-)

  • @shikhahaldar5098
    @shikhahaldar5098 4 роки тому +3

    Sir, let me take moment for truly appreciating your digital hand art so perfect 🙆🥴

  • @FarFromEquilibrium
    @FarFromEquilibrium 16 років тому +2

    Sal I cant wait for your 5 part video on integrating Maxwells wave equation!

  • @dtorti4
    @dtorti4 13 років тому +1

    dude i have to say, i loved it, i actually knew this stuff but you make it so easy to learn, appreciate the video a lot.

  • @LISA.WANG.
    @LISA.WANG. 3 роки тому +3

    Wow I was getting hyped for all the comment praises for a hand he’s gonna draw, and I was not disappointed 😂👏

    • @LISA.WANG.
      @LISA.WANG. 3 роки тому +1

      @@felixwang2539 😆👍

  • @urdouchbag
    @urdouchbag 14 років тому

    a little explanation to the formula B=u0 i /2 (pi) r....
    using gauss' theorem's equivalent in magnetics..(Ampere's Circuital Law)...
    B.dl=u0.i in gauss law we had..E.dS=Q/e0
    so in this case..
    B.(2(pi)r)=u0.i dl=2(pi)r for a circle(circumference)
    we have to find B...
    B=u0.i /2(pi)r

  • @MuneerAhmed-fx7vn
    @MuneerAhmed-fx7vn 5 років тому +1

    V nice 👍

  • @Nerdyhornist
    @Nerdyhornist 8 років тому +16

    how do you know everything

  • @kin4seikatsu844
    @kin4seikatsu844 8 років тому +4

    Great teacher and a greater artist! Had such a hard time understanding this in lecture but you made me understand it within less then 10min. Thank you!

  • @nirlepkaur3052
    @nirlepkaur3052 7 років тому +1

    Thank you so much ! U solved my problem in not more than 3 minutes 😇

  • @TheOneToxic
    @TheOneToxic 14 років тому

    can i just say you are really good at art considering your using a tablet which are hard to use XD
    Lovely lessons!
    Oh, im going to make the hand blue....very professional ;)
    Thanks!

  • @squarkman
    @squarkman 15 років тому +1

    Does the shape of this magnetic field that disipates based on the radius from the moving electron, form a sphere by adding up growing and shrinking concentric circles?

  • @squarkman
    @squarkman 15 років тому +1

    Does the intensity of the mag field associated with electron x, move along the wire with electron x? So it would be like a spherical field force moving a foot with every foot of distance moved by electron x?
    But if electron x causes a mag field, this field is not affecting the electron field in the previous second so it seems like it creates a huge undefinable mess of electron fields that cannot be rigorously defined.

  • @sammysmith1848
    @sammysmith1848 7 років тому

    This concept has been in use for many many years. Scrap yards use this exact same set up.

  • @MrSadik11111
    @MrSadik11111 11 років тому

    Thank you for the method!

  • @jasondove2647
    @jasondove2647 9 років тому +48

    is it bad if i watch these for fun...

    • @roneyandrade6287
      @roneyandrade6287 7 років тому +16

      NO NEVER THINK THAT!

    • @jinjin7594
      @jinjin7594 7 років тому +2

      Jason Dove yes

    • @AnnSnowfrost
      @AnnSnowfrost 6 років тому

      That's great! What makes you think it's bad to watch them for fun?

    • @afif4738
      @afif4738 6 років тому

      Yes, nerd

  • @MarkQub
    @MarkQub 2 роки тому

    14 years and video is still gold!

  • @NarutoMessi1
    @NarutoMessi1 11 років тому

    "That's why you don't have metal objects being thrown around by the wires behind your television set"
    Hilarious! :D

  • @林楷晟-d1y
    @林楷晟-d1y Рік тому +1

    wow the drawing skill lol, great video

  • @jhonma1
    @jhonma1 15 років тому

    Spectacular explanation
    than you.

  • @michaelburket9024
    @michaelburket9024 7 років тому +1

    Is r measured from the edge of the wire or the center. I'm assuming center. My applications involves using several laminations of copper

  • @sra_an9412
    @sra_an9412 4 роки тому

    thanks
    it helped me

  • @quitejaded
    @quitejaded 16 років тому +1

    Damn, I discovered your videos in the middle of the summer semester and I wasn't able to catch up. I just finished my final yesterday. I wish I found you sooner. But atleast I'll have you for Calc2, Economics, and Linear Alebra, right? RIGHT? :(

  • @Max11551
    @Max11551 16 років тому

    Sal could you (or maybe someone else who knows) tell me where I can get that TI85 emulator? Is it commercial?

  • @andrewz641
    @andrewz641 5 років тому

    omg the drawing is so nice

  • @voltairer.2919
    @voltairer.2919 2 роки тому

    Your English is excellent. I would never know that you are not a native English speaker.

  • @mistersinister2043
    @mistersinister2043 9 років тому +6

    What is the physical reason why the field spins counterclockwise to the current's direction?

    • @ccmiint
      @ccmiint 9 років тому

      +MisterSinister A current in a wire creates a magnetic field. Using a compass you can see that field and find its direction. To help figure out the direction Ampere has created the right hand rule. It's just a standard rule so everyone follows the same convention and agrees on direction. Check out right hand rule on wikipedia for a demo.

    • @mistersinister2043
      @mistersinister2043 9 років тому

      ccmiint Yes, I understand it is merely for convention now.

    • @AndyU96
      @AndyU96 8 років тому

      +MisterSinister I believe it is something no human knows why. We just observe the thing. ccmint's answer isn't answering your question in a sufficient way.

    • @mistersinister2043
      @mistersinister2043 8 років тому +2

      EmirhanMW2 It is just convention, meaning there is no actual reason. It's just so everyone uses the rule the same, like labeling one direction left and one direction right, even though there is no real difference.

    • @AndyU96
      @AndyU96 8 років тому

      +MisterSinister Excuse me but, as matter apparently doesn't have it's own mind, then it actually matters whether a current carrying wire throws you counter-clock wise, or clockwise.
      A person should ask, why does it go counterclockwise, and not the other way, isn't it the same thing?
      I don't think it is a 'convention', but rather, an observation.

  • @taters1123
    @taters1123 11 років тому +3

    You sound like Mircrosoft Sam. But you're awesome.

  • @noneofurbusns3139
    @noneofurbusns3139 9 років тому +4

    first rule of right hand, you can also imagine yourself opening a bottle of water for example in a certain direction in goes up..

    • @zaidachmed868
      @zaidachmed868 6 років тому

      None ofurbusns ya thats known as screw rule

    • @hayafatima3190
      @hayafatima3190 6 років тому

      outstanding nd easily digestable example of a bottle

  • @shadabquamar4922
    @shadabquamar4922 4 роки тому +2

    salman sir had a hidden talent of art......😆👍

  • @GTSD00D
    @GTSD00D 14 років тому

    @cheese0cake Right hand rule relates to Protons, conv current deals with protons. If you use left hand rule, your dealing with electron flow

  • @viktoriyat6131
    @viktoriyat6131 7 років тому

    In headphones, how does the current flow affect the magnetic poles in the voice coil?

  • @oversoul9248
    @oversoul9248 7 років тому

    how to demonstrate the expression you wrote of B created by a wire please?

  • @mihiro271
    @mihiro271 13 років тому

    one question
    is there a symbol x in circle denotes inwards whiole the . in circle denotes outward curent

  • @shaheer_ghazi
    @shaheer_ghazi 4 роки тому

    God bless you

  • @struggler98
    @struggler98 12 років тому

    salman thank you
    شكرا سلمان

  • @videoface12
    @videoface12 9 років тому +2

    So helpful, man. Thank you.
    This also works to describe how coherent self-awareness would go about looking at itself and how energy is in flux because it can't be created or destroyed. The universe being one of those concentric circles.
    Energy/magnetism = vector self-awareness

    • @nitishchauhan8655
      @nitishchauhan8655 9 років тому +1

      +Alex James do you smoke crack?

    • @SomeGuy-pv4lr
      @SomeGuy-pv4lr 9 років тому

      +Nitish Chauhan thanks for bringing my attention back to this video. This guy is amazing. The mechanism that's happening is not one of self-awareness. It's one of experiencing the procedure of expatiation. That's the side-effect of the fusion of the electric current and plasma. Space is spinning counter clock wise while time is spinning clock wise. That's the result of positive and negative charges behavior in a vortex.

    • @nitishchauhan8655
      @nitishchauhan8655 9 років тому

      you have a lot fun doing that don't you

    • @MrClips11
      @MrClips11 9 років тому

      +Nitish Chauhan Physics? Yeah, because it coherently explains the Nature of Existence.

    • @nitishchauhan8655
      @nitishchauhan8655 9 років тому

      dude do you just say shit and hope people won't understand that everything you write is complete bonkertown?

  • @skinner9399
    @skinner9399 5 років тому

    I think the wires would repel each other.

  • @trinity1969
    @trinity1969 4 роки тому

    Also, did you know we can create charge through magnetic field because of induction?

  • @samisarwar2956
    @samisarwar2956 3 роки тому

    If the subtitle were in English, it would be easier to understand, please consider that!

  • @hardikvyas1948
    @hardikvyas1948 7 років тому +1

    We assume mu (U¡=4pi * 10^-7 T m/A

  • @shakazulutu
    @shakazulutu 4 роки тому

    Направете превод и на български, вярно е, че много от нас знаем английски в достатъчна ст-н, но един вариант на същото това видео и с български превод, би бил много-, много по-разумен! И ще постъпите доста по-конструктивно, когато създавате едно такова видео, като го "снабдите" и с български превод ПО НЯКАКЪВ начин, хора!

  • @housegfortuna1239
    @housegfortuna1239 6 років тому

    is the mu relative permeability or magnetic permeability?

  • @نجٍمةآلُِبَحٍرٍ-ك3ج

    Good

  • @oO-point-Oo
    @oO-point-Oo 3 роки тому +1

    Can i find M permeability in casio fx-991ES plus ???

  • @jpjpjpjpx
    @jpjpjpjpx 11 років тому

    Seal is an artist

  • @faishalreza8814
    @faishalreza8814 7 років тому

    khan is great

  • @fleshcookie
    @fleshcookie 11 років тому

    God Sal is a great drawer

  • @prateekchauhan732
    @prateekchauhan732 9 років тому +4

    cool

  • @sakolsavannka5171
    @sakolsavannka5171 4 роки тому

    we should think about protons and neutrons if they have a moving what it makes the current the reason they make the current because of motion of protons and neutrons .

  • @423Mark
    @423Mark 15 років тому +1

    How do we know which way the current is flowing? Does it flow from positive to negative or the other way around?

  • @RamisaAnjum
    @RamisaAnjum 5 років тому

    What will happen if I place a magnet in this kind of magnetic fields?

  • @Damla196
    @Damla196 11 років тому

    Jasman Gill, left hand rule is different..

  • @mustafahashimkhan
    @mustafahashimkhan 14 років тому

    What is this "mu" that looks like a "u'!! you rock sal

  • @0NicoleR0
    @0NicoleR0 6 років тому

    the constant is 1.26 x 10^-6 and pi is 3.14
    how then are you getting a repeated 1.3333?
    I plugged in those numbers and got 1.19 x 10^-7

  • @hippoaction8310
    @hippoaction8310 6 років тому

    how come iron filings arent affected by the magnetic field of the wire when i try it out ?

  • @OlceOktavia
    @OlceOktavia 7 років тому

    that right hand drawing though hahahah nailed it!

  • @faizakhan3338
    @faizakhan3338 10 років тому +1

    good job..

  • @superandy456
    @superandy456 13 років тому

    On the website this is embeded on its only in 360p but here its only in 240p it makes no sense. :S

  • @sabreen446
    @sabreen446 8 років тому

    please i want to know why the magnetic field created around a wire

    • @AhmadKhan-sp3qb
      @AhmadKhan-sp3qb 8 років тому +1

      sa breen no one knows this uptill now.faraday when asked about this said it was a miracle

  • @NiiGHTBURN
    @NiiGHTBURN 9 років тому

    So cool thank you so much sir

  • @alanharding81
    @alanharding81 12 років тому

    I created a UA-cam account just so I could like your videos

  • @Belmior
    @Belmior 7 років тому

    Hmm if a coil is producing this field, how can I use another coil to pick this magnetic field up? I don't want to receive the electric field but the magnetic

  • @miidy1102
    @miidy1102 6 років тому +1

    just fyi Uo = 4pi × 10^-7

  • @PhanyMany
    @PhanyMany 11 років тому

    I thought you're supposed to use your left hand for wires??

  • @haniefsofi
    @haniefsofi 4 роки тому

    The result you used is only true when the wire is infinitely long. You
    Should have mentioned that.

  • @Arzenimus
    @Arzenimus 14 років тому

    Hahahaha "These are the veins on my hand" killed me! xD

  • @laelfoo2285
    @laelfoo2285 Рік тому +1

    Didn’t know I was watching art class

  • @jasmangill3082
    @jasmangill3082 11 років тому

    We were taught at school it left-hand rule lol

  • @assylkentaukenov4565
    @assylkentaukenov4565 4 роки тому

    watched

  • @Chelsea-gs7qj
    @Chelsea-gs7qj 7 років тому

    I assumed there wouldnt be a video on this because of the black platform and lack of hands..I stand corrected

  • @Legolas0292
    @Legolas0292 9 років тому

    I have a doubt whenever I try to define the direction of the magnetic field B: in the wire's plane the direction would be k (defining k as a unit vector that comes out of the page). But if I want to know the direction at all points, should I define a unit angular vector in cylindrical coordinates?

  • @MrMereum
    @MrMereum 6 років тому

    Uo=4pi*10^-7

  • @BBoy_Dreidel
    @BBoy_Dreidel 13 років тому

    @darkshadowz1994 Do you still have it?!?!

  • @animeshmondal1208
    @animeshmondal1208 9 років тому

    Does it matter if the current is carried by holes or electrons? The direction of the field would still be the same? I know current direction would be the same, I am just wondering if this theory is valid for both cases.

  • @handlethisnut
    @handlethisnut 12 років тому

    Damn those are nice hand drawings

  • @zaidachmed868
    @zaidachmed868 6 років тому

    This is the only video on youtube which explains why magnetic field is outside/inside of the plane.

  • @devendergoudappannagari545
    @devendergoudappannagari545 6 років тому

    Ok it's better.

  • @cullum14
    @cullum14 14 років тому

    @Ardi1589 i think it is

  • @cullum14
    @cullum14 14 років тому

    @Ardi1589 yeh i think so

  • @alirahmath706
    @alirahmath706 9 років тому

    its cooooooool

  • @MaloCrafted
    @MaloCrafted 4 роки тому

    Im so dam confused. Both my textbook and workbook explain the left hand rule. Yet this video says use the right hand???

    • @cee4873
      @cee4873 4 роки тому

      If it's a proton you use your right hand and if it's an electron you use your left hand!

  • @abrarshahriar4039
    @abrarshahriar4039 7 років тому

    IS THE CURRENT D.C?

  • @yeskendirbagytzhan645
    @yeskendirbagytzhan645 4 роки тому

    +

  • @kuanyshbeksagyngaliyev7762
    @kuanyshbeksagyngaliyev7762 4 роки тому

    Khan Academy

  • @captaintamil7100
    @captaintamil7100 4 роки тому

    U thought it would be poor but u mde me understand