Charges flow *through* batteries of course. A common high-school misconception is that no current exists in the electrolyte, or that battery internal impedance is large (when it's actually near zero.)
Electrons don't flow in circuits, they flow in *metal* circuits. Include a human in your circuit (electric shock,) and there's no electron flow in that living tissue. Same with salt water, the earth, etc. Yes, all circuits are conductors with flowing charge, but they aren't all metals w/electrons
I think you said something that's not completly correct Sal. The electrons has different speeds (m/s) before and after the resistance, but the current is the same. The electron are just more "dense" after the resistance right? Because they loose some of their speed and therefore some energy which leaves the circuit as heat?
@DoS37 by definition of current "rate of flow of charge"...if u say after the purpose of the resistor is to resist the flow of current ..ths means less flow of electron pet unit time..in other words we can say that we have slow down the electrons...by applying resistance in the path of flow of electron
Yeah but then has the current and the voltage changed from a scenario without a resistor? Because they travel slower you say, and therfore has lower energy, which leads to less voltage. And since they travel slower, there is a lower current aswell. Am I following you correctly?
sorry sal im already confused. Do the electrons flow from the negative terminal tot he positive or positive to negative?? you've lost me there. anyone answer this. plz :D
@gotty19 Electrons flow from negative to positive. Although we say that the "current" flows from positive to negative. But the electrons always flows "against" the current.
@ShakkIsLife true, if you're certain that the conductors are metal. If they're electrolytes, then the charge is both pos and neg, and flows in both directions. Same with plasmas. In Proton conductors the charges flow from pos to neg. Physics simplifies this stuff by ignoring the actual charges polarity and declaring them all to be positive. Realworld Ammeters measure CC Conventional Current, and they can't detect the charge carrier polarity.
Wow, thanks. I've been reading about power supplies and the book was telling me the "wrong" direction of flow and it was really stunting my learning. Does this mean you can measure any circuit's in/out w/ multimeter set to ohms and divide that number by the voltage it needs and get how many amps you need for it?
@abtarabishy It was Ben Franklin who came up with the sign convention for currents and charges in the late 1700s. At that time there was no way he could have known that the charge carrier in metals is the electron. It would not be until JJ Thomson discovered electrons about a hundred years later that this became an issue, but by that time the convention was firmly entrenched.
To be honest, his videos are worth watching over and over again because of his simple methods of teaching the subject. No doubt some critics have pessimistic intentions concerning his English Grammar and Pronunciation of the words. No man is complete and it is obvious that this gentleman is not an English native, but might be a descendant of either Indian origin or Pakistan.
If i was to try explain why current was initially chosen to flow from + to - i would look towards ions. When an electron is lost, the atom has an overall + charge in basic terms. So... if you relate this to circuitry it would seem that electrons are lost from the anode giving it a positive charge and "arrive" at the cathode giving it it's negative charge. However wrong it may be, it was the first thing i expected before being told how electrons actually flow in a circuit. If that helps? :)
@lazer1235 its only convention. actually called passive sign convention. There are probably vids on how it works. including power dissipation. power going into circuit, power leaving circuit, power from place a to b.
Mr.Khan, I understand that you are trying to stay as close to reality as possible with the direction of electron flow. However, most or all students that watch this video want to learn the way it is taught in class. So, can you please stick with the "wrong" way the electrons flow? I still love your videos. Thank you.
@ficklegirl11 The Khan Academy is about delivering quality education, not conforming to extensive and exaggerated notation traditionally adopted by public education systems. If you want to purposely learn this in the unintuitive way just to pass your class, then sorry bud, but the Khan Academy wasn’t created with you in mind. And given that fact, there’s nothing that you should be complaining about.
I guess I meant the combination of software and hardware. I imagine that there must be some kind of tablet, akin to a small interactive whiteboard, that you can use with a stylus "pen" to write and draw on.
@Dajavoutube you meant to say software, right? for this particular video, Sal used Microsoft Paint. But in later videos, he used some other software that I am not familiar with. You could probably try googling: Sketching software or something like that.
These videos provided a good background for circuit analysis, but they haven't helped very much with my college level circuit analysis (far more complex). So, I made a video that might help some others who are confused (until Khan can expand on his points). Just add to youtube.com
Bickering over grammatical errors over the internetz further proves that the human race is actually devolving. Rather than doing something productive with our lives, we get into e-battles on youtube. Awesome! How far we have come...
@kevinyo12 yes, someone learning this doesn't give a rat's about direction of flow... put + to + and minus to minus. The reason for the "old" flow thought is the concept of ground., lightning goes to ground, therefore, the positive charge of flow is created and seeks a ground. Save the theory for a different video. Keep It Simple Stupid ! His problem of continue to correct flow direction.. ruined the video!
Free energy has been here for a while ,But the Big corporations spend millions to ensure that information does not spread to the masses,Get a real free energy motor at LT-MAGNET-MOTORdotCOM ,Big change is comming soon!
i was also taught before that it was the + which had the power not neg.
one way to test this is.. connect one lead wire of a light to postive and ground the other .. if the light goes on ..its the positive that holds it.. try it also with negative..
attach one to negitive and ground the other wire from a light.. HEY it doesn't go on.. what do ya know
Hey, It would help if you had a separate video in between Electric potential energy and circuits talking about Ohms Laws. Just a suggestion based on what our curriculum is at school. :)
Hey, It would help if you had a separate video in between Electric potential energy and circuits talking about Ohms Laws. Just a suggestion based on what our curriculum is at school. :)
You sir, are the greatest instructor about this, to me you know so much about this and explain it in extreme depth. Very informative and helpful, love the videos. You have helped me with all my questions and confusions 5/5 keep it up!
Thank you. You are the best teacher I`ve ever had. Especially the positive and negative end, and the travel of electrons had me confused from other sources. I just find it extremely weird that they keep that "other way around" confusion.
@rinwhr Think of the electrons as cars going round a one-way road. If the cars in front slow down, and the cars behind are moving really fast, there will be a crash. We don't want this to happen. In the same way, the electrons don't want to bump into each other if they don't have to, and so the elctrons behind the electrons in the resistor must go the same speed, or electrons will be bumping into eachother all over the place, and no current would flow. Current means the flow of electrons.
@rinwhr He means that without the resistor, it would go lets see a speed at 100 but with the resistor it goes a speed at 50. but the electrons dont build up, they flow constantly. the resistor makes the electrons go slower, but there is a constant flow no matter what throughout the entire circuit.
@Yohannesiscool Kirchoff's Rule is simply the Loop Rule and Junction Rule. Loop rule is everything in a contained Circuit loop must be equal, and Junction rule is any Current going in must equal all Current going out.
ok, i love all your videos....have been watching them since First year engineering. One quick note, about ohms law.....that phenomenon has to be clearly explained as constant. When V/I is constant, then and only then ohms law can be mentioned. Thanks :)
Mass-Energy Equivalence was used in the development of the atom bomb. What happened at Hiroshima and Nagasaki proved it worked.
The reasoning is simple. Newtonian Physics said if you traveled at the speed of light, you should see peaks and troughs of light waves. Maxwell's equations forbids that.
Where is the proof either exists?
It is not an optical illusion, you go back in time.
Einstein's theories have been proven experimentally. E=mc^2 has been proven by studying electrons almost at the speed of light and the atomic bomb. General relativity has been proven during a solar eclipse by showing that light was bending because of bends in space time. Particle smashers have never been able to go past the speed of light. Synchronized clocks have been seen going differently when they are moving. Once more, I never said laws.
Torsion Fields are a pseudoscience topic with severely flawed postulates. Neutrinos do in fact have both energy and mass. Gravity is the weakest of all forces. Why should it succeed where electromagnetism failed? A household magnet is stronger than all of the earth's gravity. That is a sample of the greater difference between the forces. It is just that most molecules are magnetically neutral, so we don't experience it as much as gravity. Gravity is only noticeable because earth is massive.
But, if it goes that fast, why doesn't it go just a little bit faster? It is 3 m/s away. Why not a little faster? Only three logical explanations exist, or that I know of. The workers got tired, there was not enough funding, or it's impossible. They can hire new workers, or seek one of several ways to earn money.
The Large Hadron Collider can move protons at about 99.9999991% of the speed of light. Why won't it go any faster? why not 101%? I never said "law", by the way. Why did you include it in the comment? Theories can, in fact, also be supported by observations. But, they can be falsified. Theories can be edited. But, E=mc^2 's derivation is so simple, all it requires is some background in calculus.
How about this. When you run, you require energy. As you approach the speed of light, it requires tremendous amounts of energy. that translates, through E=mc^2, more mass, requiring more energy to move it further. In the end, it requires infinite amounts of energy to travel at the speed of light. You probably have no background in this. To call this child play is stupid, considering the time people spent on this without finding contradiction.
i agree with you jaguar. There is actually believed to be particles that cannot go SLOWER than the speed of light, but can go up to infinity faster. If humans harnessed this, we could surround a spacecraft with these particles, arrive at our destination, then drop the field. Its hard for diade to understand that, as with many people, which is prolly why hes diagreeing. Dont worry, I know your right :D
Those particles have always meant the end of a theory. Every time they appeared, the theory was modified. Please see me response up there. Really, please do.
I understand that. However, in the LHC and other colliders, they are unable to accerate particles to the speed of light, so currently, Einstein's theories are holding strong. And they are basically the building blocks of all other theories since Einstein's time. They are accepted as fact by the large majority of the scientific community.
If your going to disagree with the fact that an object with mass can travel at or faster then the speed of light, you should not be viewing physics videos. But go ask your little alien friends, im sure they'll be happy to answer your questions with answers that your little mind can comprehend.
Go try it then, if you can make an electron exceed the speed of light, you will prove a very very large amount of scientific theories wrong, Best of luck.
V=(current)*(resistance), or V=IR, current uses Amps as a unit of measurement as resistance uses ohms as a unit of measurement, however "I" denotes current but is written in units of "A", or amps.
AD64039 IS AN IDIOT AND HAS NO IDEA ABOUT OHMS LAW. V=AxR, THAT VOLTS EQUALS AMPS TIMES RESISTANCE OR R=V/A, A=V/R AND THAT DOESN'T MEAN YOU STILL DON'T NEED TO KNOW WATTS LAW. SOME PEOPLE THINK THEY KNOW IT ALL. HA!
This guy sucks, electrons going from + to - is called the "Conventional Theory" which is what we first thought when we saw electricity moving. Like the l.e.d. signs that are going one direction but look like thier going another. Once we had the technology of microscopes to see the electrons moving we figured out they actually move from - to +, this is called the "Electron Theory" The people who use this are engineers. The conventional theory is still used in cars, houses, etc.
This comment has received too many negative votesshow
It's ok bro, i know you think you know it all. But you shouldn't talk because it makes you sound stupid. And yes i can read. Can you??? If we can't see electrons move then why do we have the Electron Theory? Not much need to prove myself to the likes of you. I am attending school for this crckhead4488. Your ignorence is an embarresment. In other words, your an imbecile
ironman--Here's a thought: Before calling someone an imbecile, you should learn how to spell, captialize, and punctuate properly. Basically, you should learn how to write. Mmmm-kay? FYI: It's "ignorance" and "embarrassment". Also, in the last sentence, it's "you're," not "your".
@3e3op88 stfu with that grammar stuff. who cares if he capitilizes or not, this is not a formal letter that, hes handing into a professor. if your gonna criticize something, criticize what hes saying. and yes i didnt use caps to piss you off.
@3e3op88 He just wrote it fast and was to lazy to correct it the point is he is smarter than you. Just a couple of errors in his text doesn't mean anything. Bitch.
@kiemul136 well, but to mistake "You're" with "Your" isn't just fast, it's also ignorant, same as " I should of done this" instead of "I should have done this"...
It's just proof that such person never took a hold of a book and read it
err it actually makes a little sense to consider the direction of flow to be from pos to neg sign charge,
this way, as charges will want to move towards a lower pot energy in the direction of the field vector, they will give up positive sign "kinetic energy" as they do, which translates to electric current.
otherwise we'd be dealing with negative potential diffs, like the drop over a resistor will be -0.5V, or a regular battery will be labeled "-1.5V", which would really sound awkward.
I dont get how the resistance has anything too do with the voltage, I get that the current is relative too the voltage, but voltage and the resistance?? please explain. thanks.
say the resistance is a cashier and charges are clients.
So, for a charge to pass through it has to consume a bit of its own energy to overcome such resistance. so the tem voltage or potential difference is considered the work consumed by the charge to cross such resistance.
so we cosider charges flow from high potential to lower potential.
Electricity is a flow of electrons (negatively-charged particles). So the electrons will be attracted to areas of positive charge, and will flow to that area, so the electron flow is ACTUALLY from negative to positive. BY CONVENTION, however, electrons are depicted moving from positive to negative. I THINK this idea started out because people assumed that electrons would move to areas occupied by their own kind, before they knew about electrostatics. Since this idea does not necessarily...
the convention is the opposite of reality, because the convention represents the flow of positive charges. Since electrons are moving from the right to the left, the positive charges, the lack of electrons, move from left to right.
This comment has received too many negative votesshow
There is a mistake.
You are confusing Charge with Current. You are using them interchangeably. Current which is I = dq/dt. Your saying that this is an electron moving but it's not your confusing it with charge which is −1.602176487(40)×10−19
Current does go from negative to positive. The reason why people think that it goes from positive to negative is because (as Sal said) the original pioneers of electric technology mislead us by saying that the current flows from positive to negative.
Your right. I was wrong. The reason it is, is Benjamin Franklin didn't know what electrons where. But in engineering (circuit making in this case) goes from positive to negative.
Sal, you should write a book on physics! Most books are not that great.
Clipster15 2 weeks ago
Charges flow *through* batteries of course. A common high-school misconception is that no current exists in the electrolyte, or that battery internal impedance is large (when it's actually near zero.)
Electrons don't flow in circuits, they flow in *metal* circuits. Include a human in your circuit (electric shock,) and there's no electron flow in that living tissue. Same with salt water, the earth, etc. Yes, all circuits are conductors with flowing charge, but they aren't all metals w/electrons
wbeaty 1 month ago
Mr. Alexander, you should watch this...
Footballgooner86 1 month ago
I think you said something that's not completly correct Sal. The electrons has different speeds (m/s) before and after the resistance, but the current is the same. The electron are just more "dense" after the resistance right? Because they loose some of their speed and therefore some energy which leaves the circuit as heat?
DoS37 2 months ago
@DoS37 by definition of current "rate of flow of charge"...if u say after the purpose of the resistor is to resist the flow of current ..ths means less flow of electron pet unit time..in other words we can say that we have slow down the electrons...by applying resistance in the path of flow of electron
775shahrukh 2 months ago
@775shahrukh ..
775shahrukh 2 months ago
@775shahrukh
Yeah but then has the current and the voltage changed from a scenario without a resistor? Because they travel slower you say, and therfore has lower energy, which leads to less voltage. And since they travel slower, there is a lower current aswell. Am I following you correctly?
DoS37 2 months ago
@DoS37 sorry i couldnt get u
775shahrukh 1 month ago
Your one of the cool famous people.
zobetor 3 months ago
Comment removed
omgthatscrazyx 3 months ago
sorry sal im already confused. Do the electrons flow from the negative terminal tot he positive or positive to negative?? you've lost me there. anyone answer this. plz :D
gotty19 4 months ago
@gotty19 Electrons flow from negative to positive. Although we say that the "current" flows from positive to negative. But the electrons always flows "against" the current.
Laimonel 4 months ago
@Laimonel oh kk thanks for explaining man appreciate it! :D
gotty19 4 months ago
@gotty19
Electrons flow from the negative terminal of the battery.
ShakkIsLife 1 month ago in playlist Physics
Electrons flow from the negative
@ShakkIsLife true, if you're certain that the conductors are metal. If they're electrolytes, then the charge is both pos and neg, and flows in both directions. Same with plasmas. In Proton conductors the charges flow from pos to neg. Physics simplifies this stuff by ignoring the actual charges polarity and declaring them all to be positive. Realworld Ammeters measure CC Conventional Current, and they can't detect the charge carrier polarity.
wbeaty 1 month ago
I litteraly have a quiz on this tomarrow i am so glad that there is video i can turn to and not just my teachers lectures.
MLPFANBOY 4 months ago in playlist Khan Academy Physics
the electrons in the circuit are called conduction electrons !!! thanks for the videos salman sir
mihiro271 5 months ago
i was gonna paste a comment but realised you can talk to people who already know everything
findvoltage 6 months ago
@ khanacademy i love you soo much.. ! you're the best teacher ever!
sydniebon 7 months ago 13
Wow, thanks. I've been reading about power supplies and the book was telling me the "wrong" direction of flow and it was really stunting my learning. Does this mean you can measure any circuit's in/out w/ multimeter set to ohms and divide that number by the voltage it needs and get how many amps you need for it?
sonicfuker 8 months ago
It really annoys me that the stupid scientists had to make conventional current flow the wrong way. Like seriously!!!? Why confuse people??
abtarabishy 8 months ago
@abtarabishy It was Ben Franklin who came up with the sign convention for currents and charges in the late 1700s. At that time there was no way he could have known that the charge carrier in metals is the electron. It would not be until JJ Thomson discovered electrons about a hundred years later that this became an issue, but by that time the convention was firmly entrenched.
gullenator1 6 months ago
@gullenator1 yea i know but it's still really annoying.
abtarabishy 6 months ago
To be honest, his videos are worth watching over and over again because of his simple methods of teaching the subject. No doubt some critics have pessimistic intentions concerning his English Grammar and Pronunciation of the words. No man is complete and it is obvious that this gentleman is not an English native, but might be a descendant of either Indian origin or Pakistan.
hashmats 9 months ago
I'm always so happy to hear your voice. Thanks Sal.
crystalidx 9 months ago
Sal needs to make an "intuitive" tutorial.
mileyice13 9 months ago
If i was to try explain why current was initially chosen to flow from + to - i would look towards ions. When an electron is lost, the atom has an overall + charge in basic terms. So... if you relate this to circuitry it would seem that electrons are lost from the anode giving it a positive charge and "arrive" at the cathode giving it it's negative charge. However wrong it may be, it was the first thing i expected before being told how electrons actually flow in a circuit. If that helps? :)
shinuito 9 months ago
@amak2314 you haven't met alot of 13 year old have ya'?I do that too, but like to feel smart once in a while.
poshablyposh 10 months ago
Great video!!! Thumbs up
mstrid 10 months ago
Also, the idea of potential and such deviating talk is NOT helpful but confuses matters more in this area.
frank0067 10 months ago
NO your Not correct.. The power is at the POSITIVE terminal ..
I am hearing this all over the place about how the flow is from the negitive... but that does not work out in practice.
frank0067 10 months ago
At 3:55 he says current goes from + to -. Then why do the electrons go anti clockwise? against the flow of current? sorry im confused
lazer1235 10 months ago
@lazer1235
outside the battery is from + to -.
inside from - to +.
Skyrodude 10 months ago
@lazer1235 its only convention. actually called passive sign convention. There are probably vids on how it works. including power dissipation. power going into circuit, power leaving circuit, power from place a to b.
ubercute1sf 9 months ago
Do some soldering
NothingAtAllXD 10 months ago
great video, thanks man!!
MopDMTBARTL 10 months ago
Yo khanacademy, you should try holding shift when u do a line, it make a straight one (locking on the axis)
NinjaMotion 10 months ago
Isn't Voltage written as U ? like U/R = I ?
Rhenium1485 10 months ago
Are you sure you havent had anything to drink :P
ballsoffury4 10 months ago
Mr.Khan, I understand that you are trying to stay as close to reality as possible with the direction of electron flow. However, most or all students that watch this video want to learn the way it is taught in class. So, can you please stick with the "wrong" way the electrons flow? I still love your videos. Thank you.
ficklegirl11 10 months ago
@ficklegirl11 The Khan Academy is about delivering quality education, not conforming to extensive and exaggerated notation traditionally adopted by public education systems. If you want to purposely learn this in the unintuitive way just to pass your class, then sorry bud, but the Khan Academy wasn’t created with you in mind. And given that fact, there’s nothing that you should be complaining about.
MarvelsofaLifetime 10 months ago
gawd why did he mention that the e- are travelling backwards...
kamikrazi123 11 months ago
I guess I meant the combination of software and hardware. I imagine that there must be some kind of tablet, akin to a small interactive whiteboard, that you can use with a stylus "pen" to write and draw on.
Dajavoutube 11 months ago
Does anyone happen to know the name of the hardware used to produce this tutorial?
Dajavoutube 11 months ago
@Dajavoutube you meant to say software, right? for this particular video, Sal used Microsoft Paint. But in later videos, he used some other software that I am not familiar with. You could probably try googling: Sketching software or something like that.
Marsc0met 11 months ago
Khan's explanation is very good for basic understanding, but for a college level physics I had to make my own video. Just add youtube.com to
/watch?v=LWaPlBkzlVA
If this is inappropriate I'll remove. Hopefully, Khan can make a more indepth video.
review424 1 year ago
This has been flagged as spam show
These videos provided a good background for circuit analysis, but they haven't helped very much with my college level circuit analysis (far more complex). So, I made a video that might help some others who are confused (until Khan can expand on his points). Just add to youtube.com
/watch?v=LWaPlBkzlVA
I'll remove if this isn't appropriate.
review424 1 year ago
Comment removed
review424 1 year ago
But isn't resistance futile?
TheEricBooth 1 year ago 31
@TheEricBooth Hahahahaha
aaahhhhaaaahhhh 1 month ago
this also help me itunes.apple.com/us/app/star2delta/id417605678?mt=8
richimf 1 year ago
Bickering over grammatical errors over the internetz further proves that the human race is actually devolving. Rather than doing something productive with our lives, we get into e-battles on youtube. Awesome! How far we have come...
IMBLUESTREAK23 1 year ago
This has been flagged as spam show
Fucken awesome video
chelseamate1 1 year ago
fucken awesome video
chelseamate1 1 year ago
My god! Get on with it! You talk about one little thing for 5 hours!
IHaveBigWood 1 year ago
@IHaveBigWood no-one's forcing you to watch it. skip ahead if you understand it :)
shinuito 9 months ago
we should probably build a temple for Mr.Khan and name the religion Khanism and praise him. Our religious practice will be solving equations.
ElisHong 1 year ago
tell me tutor , has any student offered sexual favours for As in your class? :))
hendsem 1 year ago
I really wish I could have an instructor like this for electrical lectures I am going through right now. He makes it simple, and thats all we need.
TommyUB 1 year ago
i love how people on youtube love to argue about mindless things...no matter what the topic of the video might be.
lpsmostwanted101 1 year ago
this guy rambles on a lot
kevinyo12 1 year ago
@kevinyo12 yes, someone learning this doesn't give a rat's about direction of flow... put + to + and minus to minus. The reason for the "old" flow thought is the concept of ground., lightning goes to ground, therefore, the positive charge of flow is created and seeks a ground. Save the theory for a different video. Keep It Simple Stupid ! His problem of continue to correct flow direction.. ruined the video!
denswin 1 year ago
This has been flagged as spam show
Free energy has been here for a while ,But the Big corporations spend millions to ensure that information does not spread to the masses,Get a real free energy motor at LT-MAGNET-MOTORdotCOM ,Big change is comming soon!
buchananfibbing 1 year ago
battery is a magical thing??
i was also taught before that it was the + which had the power not neg.
one way to test this is.. connect one lead wire of a light to postive and ground the other .. if the light goes on ..its the positive that holds it.. try it also with negative..
attach one to negitive and ground the other wire from a light.. HEY it doesn't go on.. what do ya know
frank0067 1 year ago
This has been flagged as spam show
The Oil companies are trying their best to stop free energy ideas from spreading to common people.
We need to put an end to this corruption ,start generating your own electricity now.
Look for the LT MAGNET MOTOR in youtube video search. Join the Revolution!!
buchananfibbing 1 year ago
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Hey, It would help if you had a separate video in between Electric potential energy and circuits talking about Ohms Laws. Just a suggestion based on what our curriculum is at school. :)
ex0ticzact 1 year ago
Hey, It would help if you had a separate video in between Electric potential energy and circuits talking about Ohms Laws. Just a suggestion based on what our curriculum is at school. :)
ex0ticzact 1 year ago
Very nice video, indeed highly informative. Thank you for sharing your knowledge with us, Khan.
Btw, is there an explanation as to why the old convention is opposite to the reality and it still has not been changed in most of the textbooks?
asmodeus585 1 year ago
I got lost at ohm's law. and the v= to balhblahalha. can someone explain to me that? haha 13 here.not very smart. yeah.
poshablyposh 1 year ago
@poshablyposh why are u watching videos on physics....shouldn't u be watching tv or playing videogames?
amak2314 1 year ago
Nice one...!
boeing747200lr 1 year ago
You sir, are the greatest instructor about this, to me you know so much about this and explain it in extreme depth. Very informative and helpful, love the videos. You have helped me with all my questions and confusions 5/5 keep it up!
futuresoldier7 1 year ago
your way better than matthews
gl2108 1 year ago
Thank you. You are the best teacher I`ve ever had. Especially the positive and negative end, and the travel of electrons had me confused from other sources. I just find it extremely weird that they keep that "other way around" confusion.
Julyard 1 year ago
7:54, I don't get it, why does he say that it slows down at the resistor point, but then he says it must be not be slower than the other points?
rinwhr 1 year ago
@rinwhr Think of the electrons as cars going round a one-way road. If the cars in front slow down, and the cars behind are moving really fast, there will be a crash. We don't want this to happen. In the same way, the electrons don't want to bump into each other if they don't have to, and so the elctrons behind the electrons in the resistor must go the same speed, or electrons will be bumping into eachother all over the place, and no current would flow. Current means the flow of electrons.
jewbinson 1 year ago
@rinwhr He means that without the resistor, it would go lets see a speed at 100 but with the resistor it goes a speed at 50. but the electrons dont build up, they flow constantly. the resistor makes the electrons go slower, but there is a constant flow no matter what throughout the entire circuit.
VxItachixV 1 year ago
constant even flow*
VxItachixV 1 year ago
sir, you are a life saver. thank you so much! i feel like dropping out of school and just watching your videos to learn!
dnanalahcnap 1 year ago
OMG Thank You soo much!!! I actually get all this stuff now. :)
AriesApril93 1 year ago
awesome explanations. Helped out a great deal. THanks
chobostrata 2 years ago 3
thanks man!!! you are graet teacher!!!!!
adamkazmi 2 years ago
this is really great and helpful. Can you please say something about KIRCHOFF'S RULE?
Yohannesiscool 2 years ago 5
@Yohannesiscool Kirchoff's Rule is simply the Loop Rule and Junction Rule. Loop rule is everything in a contained Circuit loop must be equal, and Junction rule is any Current going in must equal all Current going out.
TheBroadwayTiger 1 year ago
scratchy line lol
i like this guy!
soxredsox 2 years ago
ok, i love all your videos....have been watching them since First year engineering. One quick note, about ohms law.....that phenomenon has to be clearly explained as constant. When V/I is constant, then and only then ohms law can be mentioned. Thanks :)
Denmen248 2 years ago
@Denmen248 hahaha "then and only then" of course u're an engineer :P
lilangel0072 1 year ago
Great explanation! Good Jobs could you pls do more video on electrical analysis.
tainguyen01 2 years ago
omg thank you so much khan! my physics teacher SUCKS and he never teaches, but thanks to you i actually might not fail the AP test!!
baba1014 2 years ago
hey,y is this resistor present in the circuit ?
sue69696 2 years ago
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kikibarrios 2 years ago
Well, relativistic mass, yes. Rest mass, no.
loverofindia 2 years ago
Mass-Energy Equivalence was used in the development of the atom bomb. What happened at Hiroshima and Nagasaki proved it worked.
The reasoning is simple. Newtonian Physics said if you traveled at the speed of light, you should see peaks and troughs of light waves. Maxwell's equations forbids that.
Where is the proof either exists?
It is not an optical illusion, you go back in time.
Once more, torsion fields are pseudoscience.
loverofindia 2 years ago
Wait... what? You believe one part of Special Relativity, and yet you reject the other...
loverofindia 2 years ago
Please see my above post. It is the one where you talked about Tesla.
loverofindia 2 years ago
So?
loverofindia 2 years ago
Einstein's theories have been proven experimentally. E=mc^2 has been proven by studying electrons almost at the speed of light and the atomic bomb. General relativity has been proven during a solar eclipse by showing that light was bending because of bends in space time. Particle smashers have never been able to go past the speed of light. Synchronized clocks have been seen going differently when they are moving. Once more, I never said laws.
loverofindia 2 years ago
Torsion Fields are a pseudoscience topic with severely flawed postulates. Neutrinos do in fact have both energy and mass. Gravity is the weakest of all forces. Why should it succeed where electromagnetism failed? A household magnet is stronger than all of the earth's gravity. That is a sample of the greater difference between the forces. It is just that most molecules are magnetically neutral, so we don't experience it as much as gravity. Gravity is only noticeable because earth is massive.
loverofindia 2 years ago 2
But, if it goes that fast, why doesn't it go just a little bit faster? It is 3 m/s away. Why not a little faster? Only three logical explanations exist, or that I know of. The workers got tired, there was not enough funding, or it's impossible. They can hire new workers, or seek one of several ways to earn money.
loverofindia 2 years ago
The Large Hadron Collider can move protons at about 99.9999991% of the speed of light. Why won't it go any faster? why not 101%? I never said "law", by the way. Why did you include it in the comment? Theories can, in fact, also be supported by observations. But, they can be falsified. Theories can be edited. But, E=mc^2 's derivation is so simple, all it requires is some background in calculus.
loverofindia 2 years ago
How about this. When you run, you require energy. As you approach the speed of light, it requires tremendous amounts of energy. that translates, through E=mc^2, more mass, requiring more energy to move it further. In the end, it requires infinite amounts of energy to travel at the speed of light. You probably have no background in this. To call this child play is stupid, considering the time people spent on this without finding contradiction.
loverofindia 2 years ago
i agree with you jaguar. There is actually believed to be particles that cannot go SLOWER than the speed of light, but can go up to infinity faster. If humans harnessed this, we could surround a spacecraft with these particles, arrive at our destination, then drop the field. Its hard for diade to understand that, as with many people, which is prolly why hes diagreeing. Dont worry, I know your right :D
KittyRokher 2 years ago
Those particles have always meant the end of a theory. Every time they appeared, the theory was modified. Please see me response up there. Really, please do.
loverofindia 2 years ago
lady gaga
lseateal 2 years ago
at someplace in the world electrons are sped up to go nearly the speed of light but not over it.
valkin07 2 years ago
in conclusion, a potential difference of over a trillion volts will not make an electron exceed the speed of light.
diademonster 2 years ago
I understand that. However, in the LHC and other colliders, they are unable to accerate particles to the speed of light, so currently, Einstein's theories are holding strong. And they are basically the building blocks of all other theories since Einstein's time. They are accepted as fact by the large majority of the scientific community.
diademonster 2 years ago
If your going to disagree with the fact that an object with mass can travel at or faster then the speed of light, you should not be viewing physics videos. But go ask your little alien friends, im sure they'll be happy to answer your questions with answers that your little mind can comprehend.
diademonster 2 years ago
lol at diadmonter...same here
Bey410 2 years ago
"We already have proof that extraterrestrials have been visiting earth for thousands of years..."
stop reading your comment at that point.
diademonster 2 years ago 3
Go try it then, if you can make an electron exceed the speed of light, you will prove a very very large amount of scientific theories wrong, Best of luck.
diademonster 2 years ago 2
nah, to get a mass to the speed of light, you would need potential difference of infinity :/ so more then infinity to go faster then c o.o
diademonster 2 years ago 2
V=(current)*(resistance), or V=IR, current uses Amps as a unit of measurement as resistance uses ohms as a unit of measurement, however "I" denotes current but is written in units of "A", or amps.
apoca1ypse1 2 years ago
AD64039 IS AN IDIOT AND HAS NO IDEA ABOUT OHMS LAW. V=AxR, THAT VOLTS EQUALS AMPS TIMES RESISTANCE OR R=V/A, A=V/R AND THAT DOESN'T MEAN YOU STILL DON'T NEED TO KNOW WATTS LAW. SOME PEOPLE THINK THEY KNOW IT ALL. HA!
ironman2much4u 2 years ago
V=IR not V=AR
Plus Sal Has An Electrical Engineering Masters Degree, i think he knows what he is talking about dude.
silycaon 2 years ago
V=AR...interesting, I wonder what Stark would say ironman
omogaju 2 years ago
This guy sucks, electrons going from + to - is called the "Conventional Theory" which is what we first thought when we saw electricity moving. Like the l.e.d. signs that are going one direction but look like thier going another. Once we had the technology of microscopes to see the electrons moving we figured out they actually move from - to +, this is called the "Electron Theory" The people who use this are engineers. The conventional theory is still used in cars, houses, etc.
ironman2much4u 2 years ago
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crck4488 2 years ago
Search for:
Movement of single electron captured on video
Here on youtube, and don't post again before killing your ignorance first.
kikibarrios 2 years ago
Comment removed
crck4488 2 years ago
This comment has received too many negative votes show
It's ok bro, i know you think you know it all. But you shouldn't talk because it makes you sound stupid. And yes i can read. Can you??? If we can't see electrons move then why do we have the Electron Theory? Not much need to prove myself to the likes of you. I am attending school for this crckhead4488. Your ignorence is an embarresment. In other words, your an imbecile
ironman2much4u 2 years ago
@ironman2much4u sorry but you can't see electrons...
Hudungo 2 years ago 12
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jojogal06 2 years ago
ironman--Here's a thought: Before calling someone an imbecile, you should learn how to spell, captialize, and punctuate properly. Basically, you should learn how to write. Mmmm-kay? FYI: It's "ignorance" and "embarrassment". Also, in the last sentence, it's "you're," not "your".
3e3op88 2 years ago 34
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VxItachixV 1 year ago
@3e3op88 stfu with that grammar stuff. who cares if he capitilizes or not, this is not a formal letter that, hes handing into a professor. if your gonna criticize something, criticize what hes saying. and yes i didnt use caps to piss you off.
VxItachixV 1 year ago
Comment removed
3e3op88 1 year ago
@3e3op88 In all your wisdom, maybe you could educate me. I am unaware of what the word "captialize" means.
sleigh93 1 year ago
@sleigh93 That was a typo, jackass.
3e3op88 1 year ago
@3e3op88 He just wrote it fast and was to lazy to correct it the point is he is smarter than you. Just a couple of errors in his text doesn't mean anything. Bitch.
TeenageIronman 1 year ago
@TeenageIronman Don't you get tired of having yourself around, dickhead?
3e3op88 1 year ago
@3e3op88 im not him faggot
TeenageIronman 1 year ago
@3e3op88 We're not all writing a formal essay. It's called "abbreviation" and it's not ignorant: merely fast.
kiemul136 1 year ago
@kiemul136 well, but to mistake "You're" with "Your" isn't just fast, it's also ignorant, same as " I should of done this" instead of "I should have done this"...
It's just proof that such person never took a hold of a book and read it
EXHellfire 1 year ago
@ironman2much4u u can't see electrons...
lilangel0072 1 year ago
This guy does videos on every topic. He is not an expert at electric theory or anything for that matter. I guess anyone can put a video here.
hbjon 2 years ago
he's got a masters in electrical engineering that should count for something
omogaju 2 years ago
err it actually makes a little sense to consider the direction of flow to be from pos to neg sign charge,
this way, as charges will want to move towards a lower pot energy in the direction of the field vector, they will give up positive sign "kinetic energy" as they do, which translates to electric current.
otherwise we'd be dealing with negative potential diffs, like the drop over a resistor will be -0.5V, or a regular battery will be labeled "-1.5V", which would really sound awkward.
croxbreed 2 years ago
thank you so much, this has really help me understand circuits alot more, keep up the good work :)
Snifflewig 2 years ago
This comment has received too many negative votes show
magic batteries .... is this guy mental?
JESUSSDAD 2 years ago
Current and Resistance are related to voltage according to Ohm's Law. V=IR where I is the current and obviously R is the Resistance
mad64039 2 years ago
Pay close attention between, 6:30 and 9:00. It's the pressure that slows down the flow of the electrons from the battery.
snapshots69 2 years ago
I dont get how the resistance has anything too do with the voltage, I get that the current is relative too the voltage, but voltage and the resistance?? please explain. thanks.
henkyxxx 2 years ago
say the resistance is a cashier and charges are clients.
So, for a charge to pass through it has to consume a bit of its own energy to overcome such resistance. so the tem voltage or potential difference is considered the work consumed by the charge to cross such resistance.
so we cosider charges flow from high potential to lower potential.
teslacoil222 2 years ago
These videos are awesome..very helpfull...thank you from Slovakia ;)
zvolencan77 2 years ago 2
This comment has received too many negative votes show
So which way does it flow?
Negative to Positive or Positive to negative?
You said one way and drew an arrow the other way
Lol
TheonlyChaoticzz 2 years ago
Electricity is a flow of electrons (negatively-charged particles). So the electrons will be attracted to areas of positive charge, and will flow to that area, so the electron flow is ACTUALLY from negative to positive. BY CONVENTION, however, electrons are depicted moving from positive to negative. I THINK this idea started out because people assumed that electrons would move to areas occupied by their own kind, before they knew about electrostatics. Since this idea does not necessarily...
SDenny100 2 years ago
...come into conflict with modern electrical design, the convention was kept.
SDenny100 2 years ago
the convention is the opposite of reality, because the convention represents the flow of positive charges. Since electrons are moving from the right to the left, the positive charges, the lack of electrons, move from left to right.
calvinhobbesliker2 2 years ago
This comment has received too many negative votes show
There is a mistake.
You are confusing Charge with Current. You are using them interchangeably. Current which is I = dq/dt. Your saying that this is an electron moving but it's not your confusing it with charge which is −1.602176487(40)×10−19
Xteaphn 2 years ago
Current is the amount of charge passing per second (the q in dq/dt is charge).
khanacademy 2 years ago 5
I know but the way your saying it current goes from negative to positive. But current goes from positive to negative.
Xteaphn 2 years ago
Current does go from negative to positive. The reason why people think that it goes from positive to negative is because (as Sal said) the original pioneers of electric technology mislead us by saying that the current flows from positive to negative.
igotzbigdragonballz 2 years ago
Your right. I was wrong. The reason it is, is Benjamin Franklin didn't know what electrons where. But in engineering (circuit making in this case) goes from positive to negative.
Xteaphn 2 years ago
Yes from positive from negative is called conventional flow and is used in the textbooks
igotzbigdragonballz 2 years ago
But in circuits you don't use electron flow. You do use conventional flow.
Xteaphn 2 years ago
Current is normally defined as I= - dQ/dt. This eliminates the need for drama.
randomuploadaccount 2 years ago
thanks man that helped me a lot...
pifasgarrote 3 years ago
lol ohh yeahh u saved me a lot of money.....
magicwisard10 3 years ago
Principles of Electricity video is better. It's in the Related Videos menu...
prayfertrey 3 years ago
excellent
you saved me alots of money
BOGZASV8MA 3 years ago