8.02x - Lect 21 - Magnetic Materials, Dia- Para- & Ferromagnetism

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  • Опубліковано 26 вер 2024

КОМЕНТАРІ • 401

  • @renjiththomas8797
    @renjiththomas8797 8 років тому +74

    Really, the domains generating a sound is unbelievable. I don't know, who would ever imagine such a possibility of demonstrating domains! Hat's off!

  • @anerypatel2003
    @anerypatel2003 9 років тому +50

    The sound of the magnetic domains clicking in the material is amazing. I had read about the domains and interpreted it as a hypotethical explaination(may be because I was not able to understand it completely) but now I know these domains are for real! This demonstration made me shiver and not believing it, I heard it thrice. Hats off to you, Sir.

  • @mauriciobarda
    @mauriciobarda 7 років тому +36

    I don't know why are people watching series and movies having these incredible lessons and demonstrations. You are excellent professor Lewin, I'm really glad every time I see one of your lectures. Thank you for this channel and your life job.

    • @lecturesbywalterlewin.they9259
      @lecturesbywalterlewin.they9259  7 років тому +6

      :)

    • @vitalino1981
      @vitalino1981 6 років тому +4

      Mauricio Barda
      People like to watch series because it's not require brain, in opposite to learning process.

    • @VivekYadav-ds8oz
      @VivekYadav-ds8oz 5 років тому +1

      @@vitalino1981 I disagree. I think that the series are more closely related for whatever they're studying/preparing (exam oriented education system, yey!) and hence studying them makes more sense. To-the-point material.

    • @brittanyplantagenet1516
      @brittanyplantagenet1516 20 днів тому

      😄 I agree. 🧐 I could watch this guy all day. 😍 He's wonderful! 👍

  • @Raphael_NYC
    @Raphael_NYC 4 роки тому +9

    The more I listen to Dr. Lewin, the more I love him. One of kind. Thank you for sharing your wisdom.

  • @hiranmayroy5910
    @hiranmayroy5910 8 років тому +38

    Lectures by Walter Lewin. They will make you ♥ Physics. professor,Thanks to your videos,I got a 49 out of 50 in my class test,nobody bettered me,and I will expect to do so in my board exams as well..THANK YOU Professor

  • @kevinbransky1817
    @kevinbransky1817 4 роки тому +4

    This guy makes me feel good about not knowing this stuff, because he makes it seem so simple, even while the equations and descriptions he uses are very complex. Thank you Walter Lewin for helping me remember what it meant to learn about interesting topics, and for being so open to sharing such information. I have lots of respect for you, sir!!!

  • @vadimtikanov
    @vadimtikanov 9 років тому +27

    Mr Lewin,
    this lecture had me stand up, take the battery from TV remote and assemble my own motor. Your courses are such a precious gift to students all over the world. Amazing!
    What is the formula of such great teaching?
    Thank you!

    • @lecturesbywalterlewin.they9259
      @lecturesbywalterlewin.they9259  9 років тому +23

      +Vadim Tikanov Thanks for your kind words. You can find the formula of "such great teaching" in my book "For the Love of Physics".

    • @viratrobbie3259
      @viratrobbie3259 4 роки тому +8

      @@lecturesbywalterlewin.they9259 that is some amazing advertising professor! XD Big fan from india,and of the book!!

    • @Shubham-wu5jv
      @Shubham-wu5jv 2 роки тому +2

      @@viratrobbie3259 that's not advertising it's truth How can he tell it in a comment
      Books are not just written to earn
      Do you think he would be having problem in earning remember he was a teacher at MIT

  • @jeyaraman8826
    @jeyaraman8826 5 років тому +7

    I was very much excited of this lectures contains 4 demonstrations and a powerpacked Theory class by lewin.....Im so jealous of those people listening lively lewin's class, if im there in lewin class i more luckier but while seeing this lecture via utube....it's ok to be a great fan of him and watching through online.....🙂

  • @lecturesbywalterlewin.they9259
    @lecturesbywalterlewin.they9259  9 років тому +162

    This website contains all my 94 course lectures (8.01, 8.02 and 8.03) with improved resolution. They also include all my homework problem sets, my exams and the solutions. Also included are lecture notes and 143 short videos in which I discuss basic problems.
    ENJOY!

    • @anupambiswas8746
      @anupambiswas8746 7 років тому

      Thnx sir!!☺

    • @anupambiswas8746
      @anupambiswas8746 7 років тому +1

      Sir what is the cause of diamagnetism ...Why the atoms oppose the external field ??..Plz.help me sir!

    • @DevashishGupta132435LC
      @DevashishGupta132435LC 6 років тому

      @Anupam he told that it has something to do with quantum mechanics

    • @utkarshmishra7416
      @utkarshmishra7416 6 років тому +1

      @@anupambiswas8746 if you have studied 12th grade physics , you will know

    • @blackcat-mp7kh
      @blackcat-mp7kh 4 роки тому +1

      which website?

  • @tanmoydutta5846
    @tanmoydutta5846 5 років тому +2

    Sir, you have explained to me the concepts of dia-, para- ferro- magnetism better than anybody else.... thanks for making me a fan of Physics again...

  • @ministeriomundialliberando8403

    Whenever I watch this teacher I'm amazed the way he explain the teachings and also the experiments. My highest tespects.

  • @MahmoudAhmed-oq2dn
    @MahmoudAhmed-oq2dn 3 роки тому +3

    This man has a talent for explaining physics + the budget obviously

  • @SumerKhan-jy1dn
    @SumerKhan-jy1dn 2 місяці тому

    I am indian and i watched professor s 21 lectures straight ❤ may be many of them I watched twice❤❤❤

  • @PeteVanDemark
    @PeteVanDemark 2 роки тому

    Dr. Lewin, I wish I could have studied under you. Such a brilliant man. A friendly science genius who shares his knowledge so artfully and entertainingly. That poor dog in Australia! “You can’t teach an old dog new tricks.”

  • @user-ib4bg9kg5s
    @user-ib4bg9kg5s 3 роки тому +1

    Lecturers reduced physics to formulas, and forgot it's about real life, thank you for giving a beautiful visual representation of the concepts you explain, you make all of us love physics

  • @brittanyplantagenet1516
    @brittanyplantagenet1516 20 днів тому

    🥰 You are a wonderful teacher❣️ Your students are very blessed to have you for a professor. 💝 Thanks for the great lessons in magneto-electric fields. 🙏💝 I have quite a passion for magnetic fields, piezoelectricity & longitudinal (super~luminal) waves. ✨ 😜 Woo-hoo! 👍😁

  • @ayonnasaha7087
    @ayonnasaha7087 3 роки тому +1

    What a legend. Grateful to be alive in the same era as him.

  • @BladimirBartolini
    @BladimirBartolini 7 місяців тому

    Sr 71 blackbird comes to mind. At Fourth Avenue Jr High Yuma Arizona, I a seventh grade student was lucky to have had amazing teachers. The motor that won in this video I as all of the class built. The winner was whom could biild it faster. I truly enjoyed this video not just for free knowledge, but of how easily he explained it all as commonsense. Muchas gracias from a high school dropout.

  • @cricworld6797
    @cricworld6797 Рік тому

    Hats off for prof Walter. You truly made me love for physics. Believe it or not before I started to watch your videos I hate physics and did study it just for passing the exam. Yet now I have changed myself and started to carry on my entire life linked with physics ❤️❤️

  • @gurusatyadattatreya242
    @gurusatyadattatreya242 4 роки тому +4

    This lecture had greatly helped me for my seminar... Thank you Lewin sir...

  • @johnsonspark171
    @johnsonspark171 3 роки тому +2

    I wonder if she still has the thermometer?

    • @carultch
      @carultch 3 роки тому

      I have a thermometer just like that.

  • @sanjeev1530gamil
    @sanjeev1530gamil 2 роки тому

    Sir ur way of teaching physics inspire many youngminds who come to teaching fields.
    It's unbelievable to me
    I cont express my feelings when I hear the sounds of domains.
    Tq sir

  • @kavitayendigeri6499
    @kavitayendigeri6499 6 років тому

    I don't think who is this first time I saw you in UA-cam but u r every best teacher of physics 🙏🙏🙏🙏🙏

  • @deokaransingh7943
    @deokaransingh7943 3 роки тому

    What an absolute mind blowing lecture! Never thought magnetism chapter could be so interesting. Just amazed. Thnx a lot professor for making my brain work ! 🙏🙏🙏🙏🙏🙏🙏

  • @vector8310
    @vector8310 3 роки тому +1

    This man's ability to communicate is amazing.

  • @balasbramanithangavel5933
    @balasbramanithangavel5933 3 роки тому +4

    With cracking sound, we infer that atoms changing positions - domain alignment with the field. Will a polycrystalline ferromagnetic material become a single crystalline material so that making single crystals easier? I am wondering this for a quite long time.

  • @GaganpreetSingh-ft1xi
    @GaganpreetSingh-ft1xi 5 років тому +3

    Best ever lecture. 👌🏾👌🏽👌🏿👌🏾👌🏽👌🏿👌🏾👌🏽👌🏽👌🏾👌🏿👌🏽👌🏿👌🏽👌🏿🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏💎💎💎💎💎💎💎💎💎💎😘😘😘😘😘😘😘😘😘😘💪💪💪💪💪💪💪💪💪💪👼👼👼👼👼👼👼👼👼👼Keep it up 👍

  • @ugursoydan8187
    @ugursoydan8187 4 роки тому +3

    demonstrations are very good and amazing. thank you Sir!!

  • @ujwal5742
    @ujwal5742 2 роки тому

    tq u so much sir now I understood diamagnetism.u are the great teacher u make us fall in love with physics. seriously in our college teachers won't explain like u sir .A great HADSOFT TO YOU SIR

  • @MasterMindmars
    @MasterMindmars 5 років тому

    Very good.
    There is an explanation for the domains. In a ferromagnetic material, all the electrons spins at the same direction, both in translation and rotation movements.
    A pleasure listen to you.

  • @obayev
    @obayev 2 роки тому +1

    Many thanks for such a breathtaking demonstrations!

  • @amreshkumar8730
    @amreshkumar8730 3 роки тому +1

    Dear sir, i am your great fan, i am a PGT physics teacher from India, Bihar 🙏.

  • @ElectromecanicaIndustrial
    @ElectromecanicaIndustrial 4 роки тому

    the Dipoples-domain experiment at 28:35 certainly put a smile on my face, truly amazing

  • @Faded_0022
    @Faded_0022 3 роки тому +3

    29:30 That was impressive!!! Thanks a lot Prof

  • @drbalachandratc1587
    @drbalachandratc1587 2 роки тому

    The demonstrations are undoubtedly very insightful. Would appreciate a reciprocation from Prof. Lewin so that I can share ideas.

  • @williamogilvie6909
    @williamogilvie6909 2 роки тому

    First rate demos, and very clear explanations.

  • @lordxperimental6960
    @lordxperimental6960 3 роки тому

    Absolutely legendary lecture, I miss having lectures like this.

  • @RahulkumarKumar-bx8lw
    @RahulkumarKumar-bx8lw 4 роки тому +3

    great sir
    this is the actual teaching of science through experiments
    i am also trying to teach chemistry to my students
    thanku sir
    with LOVE

  • @johnmacri7440
    @johnmacri7440 3 роки тому

    Passion is obvious & makes this fun and understandable

  • @lonenoler7618
    @lonenoler7618 4 роки тому

    Im agravated to have never had the oppurtunity to be tought by Lewin. im late to the facination of physics. the Lectures i study on youtube are like treasure.

  • @abhiksasmal3304
    @abhiksasmal3304 5 років тому +1

    Sir, why are the ferromagnetic materials used as magnetic shields?
    Ferromagnetic materials have large magnetic permeability, thus the magnetic field inside a ferromagnetic material increases to a larger value as compared to that in vaccum or air.
    Then, how does a ferromagnetic material stop or shield the external magnetic field ??

  • @BeAsYouAre108
    @BeAsYouAre108 3 роки тому

    Thanks for making your lectures available.

  • @robertfajardo2239
    @robertfajardo2239 4 роки тому

    Thank you for your contribution to worldwide science.

  • @mohammedrehman4109
    @mohammedrehman4109 Рік тому

    Wow
    I have only one Thumbs Up.
    Love You Sir.
    Long Live

  • @paulg444
    @paulg444 4 роки тому

    He is the gift that keeps giving.. if you dont love him, see your cardiologist!.. you don't have a heart!!!

  • @Xanthopteryx
    @Xanthopteryx Рік тому

    Walter Lewin for physics and Andrew Szydlo for chemistry and Matt Parker for math. Just as every teacher should be - they totally grasp you and even if you already know what they are talking about, you can not stop listening and watching.

  • @bhavishyasharma7834
    @bhavishyasharma7834 2 роки тому

    29:41 that's the most fascinating demonstration of yours

  • @umerhayat1590
    @umerhayat1590 Місяць тому

    Respect to Sir Walter Lewin from Pakistan 🙇

  • @dmnmkenya1986
    @dmnmkenya1986 8 років тому +1

    I love physics myself. if only i can change the attitude of my students towards physics I will be the happiest person on earth

    • @lecturesbywalterlewin.they9259
      @lecturesbywalterlewin.they9259  8 років тому +3

      +daniel; njuguna Make them LOVE physics and let them feel that you LOVE them too. Your enthusiasm and energy and love should be contagious. Make them laugh, make them cry, make them sit on the edge of their seats, make them stop breathing and even make them sometimes wet their pants. YES, I CAN DO ALL THAT whenever I want to.

    • @dmnmkenya1986
      @dmnmkenya1986 8 років тому +1

      I have tried n it is working. Thank you prof. I need more resources because some of the experiments you do are too lively n motivate students because they can associate themselves with it

    • @dmnmkenya1986
      @dmnmkenya1986 8 років тому +1

      yours is more lively because it is interactive and deals with real objects

  • @degisimyonetimi7867
    @degisimyonetimi7867 5 років тому +1

    Amazing experiments! U are teaching us from miles away and coming from past taking us to future. I was a impertient, ignorant teenager while this video was being recorded :)

  • @germanvaliero348
    @germanvaliero348 Рік тому

    Hello, in the laboratory I saw the following phenomenon:
    A metal ball is held by an electromagnet but if the switch is opened or the source is disconnected, it remains there for a long time, it does not fall. Sometimes it happens, sometimes it doesn't, for no apparent reason.
    The strangest thing is that if the voltage of the source is increased and then disconnected, the sphere is less magnetized than when the voltage was lower. The voltages are small values of 1.5 v of 3v
    What could be the reason for this?

  • @osopolarcl73
    @osopolarcl73 6 років тому +1

    Professor Lewin, thanks for sharing all this information. Greetings from Santiago-Chile.

  • @abhishekjaiswal9474
    @abhishekjaiswal9474 6 місяців тому

    Thank you Professor

  • @konstantinpatroev8130
    @konstantinpatroev8130 3 роки тому

    Inspiring teaching as always!

  • @yuriboldt5320
    @yuriboldt5320 4 роки тому

    The lecture was really intuitive. I am here to brush up a bit haha. thanks, sir. Awesome! Very good your lectured.

  • @chessinsaaninsaan502
    @chessinsaaninsaan502 4 роки тому

    Sir u are great. Ur problem solving and concept classes really help to solve the extraordinary problems of jee advance. Can u plz come with many more conceptual lectures on u tube. I really thankfull to u to blow my interest in physics Also.

  • @igorjee
    @igorjee 4 роки тому

    Love you Dr. Sanders! 💓🔭

  • @_Ayush_yadav_6239
    @_Ayush_yadav_6239 9 місяців тому +7

    I'm Indian guy who watch this lecture 👍

  • @ahmadeldesokey9844
    @ahmadeldesokey9844 5 років тому

    Your lectures are very colourful .

  • @johnfarris6152
    @johnfarris6152 4 роки тому +1

    You make teaching a science.

  • @jyotirmoysarma8509
    @jyotirmoysarma8509 6 років тому +2

    Epic lecture sir

  • @sereya666
    @sereya666 6 років тому +2

    Dear professor, do you have any plans in doing some content in theoritical physics? I would love to see an overview of physics like a guideline for those that gone through your lectures and wants to dive into physics more but does not know where to start.
    Let me tell you that your lectures are truly amazing and i really miss them when i can't find one in a topic i am currently working on.

  • @CaptainCalculus
    @CaptainCalculus 7 років тому +1

    When the bolt cooled down, would it be more magnetic than before? I’m guessing it would since the atoms are in a magnetic field as they stop moving.

  • @sandeeppatidar1106
    @sandeeppatidar1106 4 місяці тому

    Best demonstration

  • @Wave-Physics
    @Wave-Physics 2 роки тому

    Now I m very much cleared about ferromagnetism

  • @Aguilq59
    @Aguilq59 8 років тому

    He. Is great, love these lectures

  • @arbab64
    @arbab64 8 років тому

    Congratulation for excellent presentation!

  • @kalpanaghartimagar2301
    @kalpanaghartimagar2301 3 роки тому

    Wow 🤩🤩 awesome thanks sir for making physics interesting 😊

  • @shreya_.upadhyay
    @shreya_.upadhyay 4 роки тому +1

    How current depends on loudness created by change in domains direction? Is it because of heat generated through out or any other reason? Please anyone having answer ,Respond.

  • @Abhishek-iq1ux
    @Abhishek-iq1ux 5 років тому +1

    What was that around 6:06 - 6:07 where the pink chalk is kept. Notice carefully with minimum playback speed.

  • @KaptainLuis
    @KaptainLuis Рік тому

    thank you so much

  • @amir-wg5cw
    @amir-wg5cw 3 роки тому

    Really outstanding

  • @mahmouddesokey3818
    @mahmouddesokey3818 4 роки тому

    Congratulations for the 500000 followers

  • @sumitkumarsingh5290
    @sumitkumarsingh5290 3 роки тому +1

    Electric is the effect of magnet or Magnet is the effect of electric ?

  • @imeneezzeddine6449
    @imeneezzeddine6449 8 років тому +3

    Thank you for this amazing lecture and the so many others :) I am actually a master student (in Tunisia) and i would like to know if you have any suggestions on books or lectures about ferromagnetism paramagnetism and diamagnetism on microscopic scale ?

  • @venkateshmisra2818
    @venkateshmisra2818 6 років тому

    Awesome explanation 👌👍👌👍👏👏

  • @yourShorts428
    @yourShorts428 Рік тому

    Amazing

  • @abdurrauf7525
    @abdurrauf7525 3 місяці тому

    Respected sir, at time 9:03 you said that 'all materials when you exposed them to an external magnetic field will to some degree oppose the external magnetic field. However, in the case of paramagnetic materials, the induced magnetic dipoles are such as to increase the external magnetic field. Here, I am confused about the phrase 'all materials'.

  • @rishikeshdwivedi9511
    @rishikeshdwivedi9511 Рік тому

    So beautiful explanation sir.Sir i am here due my sir biswajeet

  • @amreshkumar8730
    @amreshkumar8730 3 роки тому +2

    Dear sir, What is your view on the existence of God and spirituality 🙏

    • @lecturesbywalterlewin.they9259
      @lecturesbywalterlewin.they9259  3 роки тому +4

      I am an atheist

    • @amreshkumar8730
      @amreshkumar8730 2 роки тому

      @@lecturesbywalterlewin.they9259 Respected sir, i like too much the way you teach physics. You are a great teacher of physics. I am a PGT physics teacher in Bihar state India. One thing i would like to know from with honestly what tis the cause of all causes and the living sprit in every creature and the source of Consciousness? Can somthing be created from nothing? What is the primordial cause of universe? Big bang theory is model or reality? If i asked you too much then forgive me 🙏 have you ever read vedas and upnisad or srimadbhagwatam and Gita? 🙏

    • @sarcasticscapegoat5995
      @sarcasticscapegoat5995 2 роки тому

      @@amreshkumar8730 He already answered all your questions in his only response to you. Everything you asked is right there. I suggest you go to some websites that don't cater to your belief or work backwards from a conclusion if you want objective answers to your questions. If your goal is to use those questions to bring any intelligent being around to your beliefs, you are waisting your time.

  • @lalleyatata
    @lalleyatata 6 років тому +1

    That was lovely thank you

  • @surendrakverma555
    @surendrakverma555 2 роки тому

    Excellent lecture Sir 🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏🙏

  • @muhammadsiddiqui2244
    @muhammadsiddiqui2244 4 роки тому

    A women, Chinese, won a tech competition and she is also so beautiful.......
    My concepts are changing........

  • @noism5429
    @noism5429 6 років тому

    this is amazing, thank you professor!

  • @Random-sm5gi
    @Random-sm5gi 3 роки тому

    Why the rotor made by Jung Eun doesn’t oscillate like in the case of rectangular circuit shown in The Torque lecture?

  • @yveslecorfec2983
    @yveslecorfec2983 4 роки тому

    May be you can try an oscillating pendulum with a french Franc and a candle. It was a pure nickel coin for a few years and hence a common display

  • @physl2787
    @physl2787 6 років тому

    sir electron moves around the the nucleas. when the magnetic dipole moment due to this motion of the electron the magnetic moment of the atom = current *area of the orbit in which electron is moving. sir electron also spin is there will be magnetic dipolemoment associated with this motion of the electron.

  • @12121sk
    @12121sk 4 роки тому

    Inspiring preparations and demos Professor! Well Done & awesome!!

  • @shashanktripathi4362
    @shashanktripathi4362 6 років тому

    great lecture, thank you, sir,

  • @patrickm4729
    @patrickm4729 3 роки тому

    how did the winning motor stop the current for half of the rotation?

  • @mastipathsala912
    @mastipathsala912 Рік тому

    Sir if a magnet and a coil are moving with uniform velocity in same direction then what emf became produced in coil

    • @lecturesbywalterlewin.they9259
      @lecturesbywalterlewin.they9259  Рік тому +1

      if magnet and the coil move jointly in the same reference frame (same velocity) then there will be no dphi/dt thus no EMF - watch my lectures

  • @neerujat1978
    @neerujat1978 3 роки тому

    Thank you very much sir

  • @mimas165
    @mimas165 4 роки тому

    @8:30 Why it is the area A that is the vector rather than the current I in the formula for magnetic moment?! I see current having the direction, rather then a surface.

  • @mohamed.hfathy3717
    @mohamed.hfathy3717 2 роки тому

    Great Lecture from a great Prof.

  • @arkadiptaghosh99
    @arkadiptaghosh99 5 років тому +1

    Sir what is hysteresis loss????

  • @almeindertsma
    @almeindertsma 7 років тому

    Thank you , now i understand

  • @rounaksinha5309
    @rounaksinha5309 4 роки тому

    Sir, I am not having Gaincoli's physics for scientists and engineers instead I have physics for scientists and engineer by Serway and Jewett. Is it okay to solve problems from it. It has topicwise problem set at the end of each chapter. So, should I solve those topicwise problem after watching the lecture of a certain topic?

  • @JaiPrakash-bk3uv
    @JaiPrakash-bk3uv 6 років тому +1

    Sir how when the magnetic dipole moment of atom is aligned with the external magnetic field than atom has minimum potential energy

  • @jigawatt1000
    @jigawatt1000 4 роки тому

    Professor Lewin, in this lecture you stress repeatedly that the poles of the magnet need to have a nonuniform field for the ferromagnetic material to have an effect and have a stronger field than the vacuum field. Could you elaborate on this please?

  • @muhammadazhar6708
    @muhammadazhar6708 3 роки тому

    great