After 18 years of learning, i can say this is the most well rounded explanation I have ever encountered. Always leave it to the British to preserve knowledge for they preserve it with eloquence.
I was a Royal Navy Electronic Engineering Apprentice back in 1991. This is like doing that course again. A wonderful walk down memory lane. Thanks man!!
Professor: I was a "straight A" science student in high school and college. While I excelled in physics courses, I never knew what any of what I learned meant. Your presentation is so clear that for once, I finally connect the reality world and course contents - in circuit tuning and in ham radio technology. I needed to know this well. Your organization of material is outstanding and your articulation of the material was so clear and precise. It's such a pleasure to learn from you through this and other videos in your series. Truly grateful. Thank you.
This, in my opinion, is perhaps the very best video on youtube. I am a part time engineering lecturer but do not have an engineering degree; I do have quite a reasonable grasp of electronic and electrical theory though. I achieved an HND and between this and my industry experience I was fortunate to land my job (which I really enjoy). Some of the classes that I teach concern engineering principles such as the content you cover in this video. Having watched it I really have a far better understanding that I have ever had and more importantly I think I am in a far better position to deliver lectures on this subject. You truly deserve all of the glowing comments that others have posted ! Your channel is a must for subscription! Thanks.
@@jacobvandijk6525 That's a ridiculous thing to say. I was taught this stuff 40 years ago with EXACTLY the same examples and mathematics and my tutors learned it 40 years previously the very same way. Giancoli had nothing to do with that, this is the work of Coulomb and Ampere, Ohm, Henri and Hertz. We all have our favourite mentors but they all teach the same principles, with the same mathematics with pretty much the same examples. Nobody's copying anyone Jacob.
"Perhaps this is the very best video on youtube". Dear, o dear. You have a high opinion of yourself, don't ya? Next learn about Relativity! Then you know how subjective this opinion is. Nevertheless, you're free to think and say what you like! But a bit more modesty would suit ya, Andrew.
I'm 16 and have just finished my first year at Sixth Form. I have always had a strong interest in electronics and I plan to study EEE at university. In the past year, my interest has moved on more from making practical circuits to learning about the physics and mathematics behind electronics. I'd just like to say that this video is the first video I have found which actually explains LRC circuits in a way which I can understand. I particularly like the fact that you give mathematical proof for the resonant frequency equation towards the end of the video as one thing that has always bugged me when self teaching is the lack of proof for equations which causes me to feel that I don't fully understand the concept. Absolutely 5 star teaching, thank you!
I received a 'D' in my Alternating Current class and did not learn much. You are a far better instructor!! I am really understanding this a lot better now, thank you!!
I bow to You - thank You so much ! I never experienced an explanation about that mysterious theme within 60min so clearly and logically.... i call it just great !!
Very good explanations, I like that you are explain how a radio can be tuned, I couldn't find explanations so clear in this directions!!! Many thanks !!!
Tons of thanks from Russia! I got it pretty smoothly though did struggle before. The explanation's utterly comprehensive. Indeed the great job, thanks again!
While I know this lacks a abundance of vocab to express how well this video made learning a complex issue is... DAAAAAAYMMMM. I've spent a long time reading documents trying to understand, you made it so easy to understand.
Two things about this video......I appreciate the simplicity of explaining complex concepts. (Complex by my standards anyway) Secondly, it just goes to show, that you dont need power point slide shows to make a presentation, and that that magic green texta of yours does a brilliant job. Full kudos to you !
Interesting guide! I am a Pole, not everything I understood. Know one thing, the math and physics is one all over the world! Thank you for your lecture
THANK YOU VERY, VERY, VERY MUCH. YOU CERTAINLY HAVE A TALENT TO TEACH. I COULD NEVER UNDERSTAND THIS. NOW I UNDERSTAND IT. YOU MAKE SO SIMPLE. KEEP THE GOOD WORK. THANKS.
Thank you for your time and effort in producing this excellent video. Doing Natural Sciences at undergrad' I know the time and thought that goes into *proper* explanations and derivations in physics of this standard. Excellent to have found an Englishman who also explains/derives in a more traditional sense, since this is more appropriate to British degrees. Thanks again!
Your videos are amazing. The concepts are clear and easy to understand for such a messy subject. They are the main reason I passed my college Physics B module, and for that I thank you good sir.
Very good explanation and background information in determining the formulas associated with Impedance. Many text books and online material I have seen tend to use these formulas but do not explain in detail where they come from or how they are derived. Thanks for filling in the gaps.
Thanks! This is the best explanation of these concepts I've ever seen. I think I'm going to be spending more time watching your videos in the near future...
Thanks. When a capacitor is charged (ie surplus of negative charge on one plate and surplus of positive charge on the other) it stores energy and is in a state of high potential (rather like the storage of energy in a battery). If you then connect it to, say, a lamp, the capacitor discharges through the lamp (causing it briefly to flash). This is because the entire system wants to fall to a lower energy state.
could've added one with parallel components but either way, hands down the best explanation I've seen :D thank you very much, sir! you've saved my butt for countless times now
You sir have done such a good deed by making these videos.... I mean you are awesome... You have made it so simple to understand all basics... Wowww... Salute to you... You hv inspired me...
This video is perfect! In my university a "professor" done the mistake you've showed in 52:44 !(and he said after it was not a mistake!) Thank you again
This is AWESOME. Very well explained. I'm currently learning electronics by myself (for fun), and this video helped me a lot. Thanks for sharing your knowledge!
Excellent video. Excellent teacher. Easy to understand, logical and methodical. This kind of videos makes TH-cam a free powerful educating tool. Inspiring as well... With a negative deferential inductance or negative deferential capacitance, can i drive the current to the realm of imaginary, creating pure imaginary circuit? With a perfect capacitor and a perfect inductor can i make resonating superconductor? Very interesting.
Great video. I feel it's worth noting that when Dr. Physics says that a relationship exists "by experiment", it does not mean that the model is lacking mathematical cohesion. The capacitive reactance, for example, follows directly from the definition of capacitance c=q/v, the definition of current i=dq/dt, Ohm's Law Z=i/v (which, granted, is experimental) and the definition of AC voltage v=sin(wt). The derivation is very simple with phasor arithmetic, but beyond the scope of this video.
Thank you very much for your videos, they are incredibly informative. I might be wrong but in this video you have only covered LCR circuits where their components are in series. Do you have any reactance and impedance videos where the components are in parallel? Or any resource (preferably a video resource) you would recommend?
Thanks for this very clear video. I noticed a slight mistake at 11:38: The north and south sides of your solenoid don't agree with your field lines (although they agree with the dots and crosses).
Yes. Well spotted. I had made an annotation at 10:33 to say that I had got the dots and crosses the wrong way round. I understand that subsequent annotations on TH-cam vids are not viewable on all devices. Sorry for the confusion.
Good explanation, but I think it would be good if you explain where Ohms law comes from (Drude model). Also it would be good to explain inductors a little bit more profund. Anyway good job 😉
nu iti mai pierde timpu dand comentarii de duzina pe youtube! cat timp tu faci asta, eu INVAT, cat timp tu stai pe chicktopia, eu INVAT, cat timp tu te aranjezi excesiv de mult in oglinda, eu INVAT !!
your channel is very interesting and very helpful ! your explanations are clear and accurate. while you so go a lot into Physics problems and physics videos, Would you ever consider going into electronics problems ? i.e. thevinin and Norton ? or circuit analysis ? :)
:The video was perfect. I just have two questions regarding the graphs at 18:00 and 26:55. Why is it that the voltage is behind the current for a capacitor and the voltage is ahead the current for an inductance?
I’ve been studying this stuff as well... For an inductor... “When a voltage is generated by a change in magnetic flux according to Faraday's law, the polarity of the induced voltage is such that it produces a current whose magnetic field opposes the change which produces it. The induced magnetic field inside any loop of wire always acts to keep the magnetic flux in the loop constant.” Thus the current is ‘delayed-lags’ by 90 degrees in an AC inductive circuit. The magnetic field in the inductor resists and sudden changes in current and wants to keep the current the same. Also known as BACK EMF...See Lenz Law en.wikipedia.org/wiki/Lenz's_law?wprov=sfti1 For a capacitor, the voltage is out of phase (delayed-lags) by 90 degrees for the same reasons as in the inductor’s magnetic field change), but it’s the ‘electric field’ flux’ that opposes the sudden change in voltage. It want to keep the ‘electric field’ the same. I’m sorry I’m not more eloquent...it’s really as much to do with the physical properties of coiled wires (inductor) and charged plates (capacitor) and how each respond to magnetic fields and charged particles.
excelleeeeennntttt explanation. I have searched a lot about why Xc=1/wC (why frequency was influencing Xc) but no one explained it so well as you did ... thanks so much. By the way can you tell me more or advise on that, you say that this result from experiment , it surprises me (I know the computations but why do you insist on experimental aspect ?) Antonio (50 years and ex electronic engineer ;-))
Thanks for great lectures. There is one concerning question. How is to understand when you say for, example, current "leads" or "lags" voltage? In which direction will the current be moving: positive or negative at time t? Thanks.
It means that there will be times when current is in the opposite polarity of the voltage waveform and the negative current indicates that the power is alternately being returned back to the source which is measured in VARs.
At its simplest, if the current is leading the voltage, then the current will reach a maximum value slightly before the voltage reaches its maximum value.
As I've said, I really appreciate the effort put into these videos. They've helped me to wrap my head around some concepts I was struggling with. Have you thought of doing a video on passive/active filters? It would seem like a good follow-up video to this. I've definitely subscribed.
I wonder if it would be helpful to clarify the following: You can "add" the (complex) impedance of an R, C and L in series together. It's the magnitude of the complex impedances that you can't (simply) add together.
complex numbers have the same properties as vectors i.e they a vectors,so you add the real and Imaginary parts together ,then you end up with complex number then take it magnitude,remember complex number are vector.take care hope this helps.
After 18 years of learning, i can say this is the most well rounded explanation I have ever encountered. Always leave it to the British to preserve knowledge for they preserve it with eloquence.
5 years later, you prevented a student from going insane. Thank you!
I've never ever seen such a clear and precise lecturer as you in my life. All I can say is WOW, and thank you.
I was a Royal Navy Electronic Engineering Apprentice back in 1991. This is like doing that course again. A wonderful walk down memory lane. Thanks man!!
Professor: I was a "straight A" science student in high school and college. While I excelled in physics courses, I never knew what any of what I learned meant. Your presentation is so clear that for once, I finally connect the reality world and course contents - in circuit tuning and in ham radio technology. I needed to know this well. Your organization of material is outstanding and your articulation of the material was so clear and precise. It's such a pleasure to learn from you through this and other videos in your series. Truly grateful. Thank you.
You've done more in an hour to help me understand several concepts than many hours of self-study have yielded. Thank you!
watching this video seven years after your posting... this is perhaps the best explanation of these two terms !
This, in my opinion, is perhaps the very best video on youtube. I am a part time engineering lecturer but do not have an engineering degree; I do have quite a reasonable grasp of electronic and electrical theory though. I achieved an HND and between this and my industry experience I was fortunate to land my job (which I really enjoy). Some of the classes that I teach concern engineering principles such as the content you cover in this video. Having watched it I really have a far better understanding that I have ever had and more importantly I think I am in a far better position to deliver lectures on this subject. You truly deserve all of the glowing comments that others have posted ! Your channel is a must for subscription! Thanks.
1
His presentation is good. But my true hero in explaining Physics will always be Mr D. C. Giancoli (in his brilliant books).
@@jacobvandijk6525 That's a ridiculous thing to say. I was taught this stuff 40 years ago with EXACTLY the same examples and mathematics and my tutors learned it 40 years previously the very same way. Giancoli had nothing to do with that, this is the work of Coulomb and Ampere, Ohm, Henri and Hertz. We all have our favourite mentors but they all teach the same principles, with the same mathematics with pretty much the same examples. Nobody's copying anyone Jacob.
"Perhaps this is the very best video on youtube". Dear, o dear. You have a high opinion of yourself, don't ya? Next learn about Relativity! Then you know how subjective this opinion is. Nevertheless, you're free to think and say what you like! But a bit more modesty would suit ya, Andrew.
@@jacobvandijk6525 Dude, take a chill pill, ffs.
I'm 16 and have just finished my first year at Sixth Form. I have always had a strong interest in electronics and I plan to study EEE at university. In the past year, my interest has moved on more from making practical circuits to learning about the physics and mathematics behind electronics. I'd just like to say that this video is the first video I have found which actually explains LRC circuits in a way which I can understand. I particularly like the fact that you give mathematical proof for the resonant frequency equation towards the end of the video as one thing that has always bugged me when self teaching is the lack of proof for equations which causes me to feel that I don't fully understand the concept. Absolutely 5 star teaching, thank you!
You sir, you are my god! How come you can explain about impedance like that? Seriously. Deep love and best karma to you my friend! Thank U!
I've just stumbled upon this channel. Thanks Bob for being such a good teacher.
I received a 'D' in my Alternating Current class and did not learn much. You are a far better instructor!! I am really understanding this a lot better now, thank you!!
I 'm final year electrical engineering - this is the best for refreshing my resonance circuits . Thank you.
This video has the best explanation of this topic, so so so clear...
I bow to You - thank You so much ! I never experienced an explanation about that mysterious theme within 60min so clearly and logically....
i call it just great !!
this is hands down the best lecture Ive seen on Xc and Xl and exactly how and why inductors and capacitors function!
Great Lecture with brief but clear description.
It clarified my many doubts about reactance and impedance.
Thank you.
Very good explanations, I like that you are explain how a radio can be tuned, I couldn't find explanations so clear in this directions!!! Many thanks !!!
Tons of thanks from Russia! I got it pretty smoothly though did struggle before. The explanation's utterly comprehensive. Indeed the great job, thanks again!
This is the best video I've found explaining AC circuits at the level I need. Thanks alot.
While I know this lacks a abundance of vocab to express how well this video made learning a complex issue is... DAAAAAAYMMMM. I've spent a long time reading documents trying to understand, you made it so easy to understand.
I have watched a lot of videos but this one was the most helpful. And thanks for examples, they helped a lot to put all information together!
Crystal clear and precise - I'm considered thick but fully understood this!! Thank you for your time and effort in delivering an excellent video!
This is actually one of the option subjects in the WJEC A-level course - this video has been extremely helpful, thank you.
One of the best explanations of the topic. Very clear and easy to follow with some basic background knowledge and math.
Excellent! I studied this for my amateur radio exam many years ago and seeing it explained rather than reading it helps a great deal even now.
Two things about this video......I appreciate the simplicity of explaining complex concepts. (Complex by my standards anyway)
Secondly, it just goes to show, that you dont need power point slide shows to make a presentation, and that that magic green texta of yours does a brilliant job.
Full kudos to you !
Ben Frawley Magic is an understatement, that thing never ran out of ink or dried up!
I also give full kudos.
Interesting guide! I am a Pole, not everything I understood. Know one thing, the math and physics is one all over the world!
Thank you for your lecture
THANK YOU VERY, VERY, VERY MUCH. YOU CERTAINLY HAVE A TALENT TO TEACH. I COULD NEVER UNDERSTAND THIS. NOW I UNDERSTAND IT. YOU MAKE SO SIMPLE. KEEP THE GOOD WORK. THANKS.
THANK YOU!! Finally found someone who CAN actually explain in a good way!
It really helped!
For real
the holy grail of impedance and reactance
Thank you very much for this high quality video! It helped a lot. Cheers from France!
Just revising for my first year exams and you explain it so much better than my professor thank you
+Jonathan Davies Same with me. Where do you study?
+Nadezhda Dimitrova Hull,England
how about you?
Glasgow Uni :) UK universities,what can I say :D
absolutley outstanding...learned more watching this video than I did in the classroom, thank you so very much !!!
I just couldn't ask for more, brilliantly explained. Thank you so much!
Thank you for your time and effort in producing this excellent video. Doing Natural Sciences at undergrad' I know the time and thought that goes into *proper* explanations and derivations in physics of this standard. Excellent to have found an Englishman who also explains/derives in a more traditional sense, since this is more appropriate to British degrees. Thanks again!
10:55 I suppose, magnetic fields must be counter-clockwise at the top (dots) and 🔃clockwise at the bottom (❌) in the picture.
This is the video on this topic that gets my HIGH PRAISE! Liked and subbed!
You are awesome i'm writing a paper on Impedance and this was the best explanation ever.
This channel is a haven of physics for me. Live long sir.
Thank you for this video. I've been self studying electronics with the intention of building amateur radios and this video helped immensely.
Best video on the topic. Thank you!
CONTINUE WHAT YOU DOING BECAUSE THIS IS YOUR CALLING... TO TEACH!!!. U MADE ME UNDERSTAND AC CIRCUITS.
Your videos are amazing. The concepts are clear and easy to understand for such a messy subject. They are the main reason I passed my college Physics B module, and for that I thank you good sir.
Very good explanation and background information in determining the formulas associated with Impedance. Many text books and online material I have seen tend to use these formulas but do not explain in detail where they come from or how they are derived.
Thanks for filling in the gaps.
Superbly explained why the higher frequency increases the Xl and lowers the XC
haven't found any other videos on Yt explaining so well this subject! thanks a lot!
Thanks! This is the best explanation of these concepts I've ever seen. I think I'm going to be spending more time watching your videos in the near future...
Absolutely well done. Very clear! Good teaching principles!
I really appreciates all the videos developed by A Level Physics.. they are very clear and helpful...
thanks a lot
Thanks. When a capacitor is charged (ie surplus of negative charge on one plate and surplus of positive charge on the other) it stores energy and is in a state of high potential (rather like the storage of energy in a battery). If you then connect it to, say, a lamp, the capacitor discharges through the lamp (causing it briefly to flash). This is because the entire system wants to fall to a lower energy state.
could've added one with parallel components but either way, hands down the best explanation I've seen :D
thank you very much, sir! you've saved my butt for countless times now
You sir have done such a good deed by making these videos.... I mean you are awesome... You have made it so simple to understand all basics... Wowww... Salute to you... You hv inspired me...
This video is perfect! In my university a "professor" done the mistake you've showed in 52:44 !(and he said after it was not a mistake!) Thank you again
My teacher taught the class that electrons are neutral. I had to correct him
This is AWESOME. Very well explained. I'm currently learning electronics by myself (for fun), and this video helped me a lot. Thanks for sharing your knowledge!
just wow... great explanation and i can't tell how much helped me to understand this complicated topic. thank you so much.
Great video. Very helpful to understand some hard concepts in a very good practical way. Thank you very much for the video.
Best explanation on the web, thank you very much!
Excellent video. Excellent teacher.
Easy to understand, logical and methodical.
This kind of videos makes TH-cam a free powerful educating tool.
Inspiring as well...
With a negative deferential inductance or negative deferential capacitance, can i drive the current to the realm of imaginary, creating pure imaginary circuit?
With a perfect capacitor and a perfect inductor can i make resonating superconductor?
Very interesting.
by far... BEST explanation of topic!
The world's best teacher thanks sir
Great video.
I feel it's worth noting that when Dr. Physics says that a relationship exists "by experiment", it does not mean that the model is lacking mathematical cohesion. The capacitive reactance, for example, follows directly from the definition of capacitance c=q/v, the definition of current i=dq/dt, Ohm's Law Z=i/v (which, granted, is experimental) and the definition of AC voltage v=sin(wt). The derivation is very simple with phasor arithmetic, but beyond the scope of this video.
Thanks from Sweden ....delightful and inspiring !
easiest explanation ever. i finally get it. thank youuu!!
Stellar presentation and preparation. Kudos!
there is no words enough to say thank you for your amazing video , I was lost with physic before i saw it
I learned more in 1 hour from watching this video than I learned in the last few months at college.
Thank you very much for your videos, they are incredibly informative.
I might be wrong but in this video you have only covered LCR circuits where their components are in series. Do you have any reactance and impedance videos where the components are in parallel? Or any resource (preferably a video resource) you would recommend?
Thanks for this very clear video. I noticed a slight mistake at 11:38: The north and south sides of your solenoid don't agree with your field lines (although they agree with the dots and crosses).
Yes. Well spotted. I had made an annotation at 10:33 to say that I had got the dots and crosses the wrong way round. I understand that subsequent annotations on TH-cam vids are not viewable on all devices. Sorry for the confusion.
I stopped reading my textbook to listen to your lecture
Good explanation, but I think it would be good if you explain where Ohms law comes from (Drude model). Also it would be good to explain inductors a little bit more profund. Anyway good job 😉
It was really helpful sir, it helped me a lot to explain the concepts to my son who is in
pre-university electronics course. Thank you very much.
this is amazingly helpful!! it's a shame that there aren't more like this
Great Tutorial love it like it you are a star.......
thank you so much for these lectures! Before watching this, I really couldn't make anything out of this subjeect, but now it all makes sense!
nu iti mai pierde timpu dand comentarii de duzina pe youtube! cat timp tu faci asta, eu INVAT, cat timp tu stai pe chicktopia, eu INVAT, cat timp tu te aranjezi excesiv de mult in oglinda, eu INVAT !!
:)))))))
esti dus =))))))))))))))))))
cat timp voi va certati, eu nu va bag in seama, pt ca INVAT.
Thank you very much for doing this, i really appreciate your help.
Marine engineer student.
Super excellent explanation... Many thanks
your channel is very interesting and very helpful !
your explanations are clear and accurate.
while you so go a lot into Physics problems and physics videos,
Would you ever consider going into electronics problems ?
i.e. thevinin and Norton ? or circuit analysis ? :)
Very intuitive and very well explained
Great Video. My only comment is I always use a dot as current coming out of the page and the X indicates current moving in a direction into the paper?
:The video was perfect. I just have two questions regarding the graphs at 18:00 and 26:55. Why is it that the voltage is behind the current for a capacitor and the voltage is ahead the current for an inductance?
I’ve been studying this stuff as well...
For an inductor...
“When a voltage is generated by a change in magnetic flux according to Faraday's law, the polarity of the induced voltage is such that it produces a current whose magnetic field opposes the change which produces it. The induced magnetic field inside any loop of wire always acts to keep the magnetic flux in the loop constant.”
Thus the current is ‘delayed-lags’ by 90 degrees in an AC inductive circuit. The magnetic field in the inductor resists and sudden changes in current and wants to keep the current the same.
Also known as BACK EMF...See Lenz Law
en.wikipedia.org/wiki/Lenz's_law?wprov=sfti1
For a capacitor, the voltage is out of phase (delayed-lags) by 90 degrees for the same reasons as in the inductor’s magnetic field change), but it’s the ‘electric field’ flux’ that opposes the sudden change in voltage. It want to keep the ‘electric field’ the same.
I’m sorry I’m not more eloquent...it’s really as much to do with the physical properties of coiled wires (inductor) and charged plates (capacitor) and how each respond to magnetic fields and charged particles.
I did not expect that accent, so I laughed a bit. Thanks for the explanation!!
made the concept crystal clear
The best explanation ever!
excelleeeeennntttt explanation. I have searched a lot about why Xc=1/wC (why frequency was influencing Xc) but no one explained it so well as you did ... thanks so much. By the way can you tell me more or advise on that, you say that this result from experiment , it surprises me (I know the computations but why do you insist on experimental aspect ?)
Antonio (50 years and ex electronic engineer ;-))
well done beginning to actually understand and enjoy.
Thanks for great lectures.
There is one concerning question. How is to understand when you say for, example, current "leads" or "lags" voltage? In which direction will the current be moving: positive or negative at time t? Thanks.
It means that there will be times when current is in the opposite polarity of the voltage waveform and the negative current indicates that the power is alternately being returned back to the source which is measured in VARs.
At its simplest, if the current is leading the voltage, then the current will reach a maximum value slightly before the voltage reaches its maximum value.
Saved me on my EMD coursework thank you :)
Awesome explaination
As I've said, I really appreciate the effort put into these videos. They've helped me to wrap my head around some concepts I was struggling with. Have you thought of doing a video on passive/active filters? It would seem like a good follow-up video to this. I've definitely subscribed.
Best video on TH-cam
omg you are just too good.. woow AMAZINNNGGG , you explain everything from A to Z.
Brilliant video! It's clear, wery well explained and so much easier to understand :) Keep up with the good work!
Excellent explanation, thank you very much.
Love you man, seriously. Excellent presentation.
I wonder if it would be helpful to clarify the following: You can "add" the (complex) impedance of an R, C and L in series together. It's the magnitude of the complex impedances that you can't (simply) add together.
complex numbers have the same properties as vectors i.e they a vectors,so you add the real and Imaginary parts together ,then you end up with complex number then take it magnitude,remember complex number are vector.take care hope this helps.
That's right. But I think I say it the other way round in the video.
That was a great explanation of this
Thank you very much.
Thank you so much, for giving a clear explanation in this video...
Reactance is the opposition from energy stored at an earlier time in a capacitor or inductor to an attempt to add more at a later time.