Resistors in series | Circuits | Physics | Khan Academy
HTML-код
- Опубликовано: 14 окт 2024
- Courses on Khan Academy are always 100% free. Start practicing-and saving your progress-now: www.khanacadem...
Resistors that come one after another. Created by Sal Khan.
Watch the next lesson: www.khanacadem...
Missed the previous lesson? www.khanacadem...
Physics on Khan Academy: Physics is the study of the basic principles that govern the physical world around us. We'll start by looking at motion itself. Then, we'll learn about forces, momentum, energy, and other concepts in lots of different physical situations. To get the most out of physics, you'll need a solid understanding of algebra and a basic understanding of trigonometry.
About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content.
For free. For everyone. Forever. #YouCanLearnAnything
Subscribe to Khan Academy’s Physics channel: / channel
Subscribe to Khan Academy: www.youtube.co...
0:48 "If there is any such thing as reality" XD
Derpy Hooves lol, Khan Academy getting philosophical...
LMAO i just came from the khan academy website to the RUclips video just to make the comment you just said!
Khan is more than a person. He is an omniscient force.
hahahahahaa
Are you guys alive in 2021
@@hassanhamze_14 are *you* alive in 2024?
"My wife will probably mind that I didn't answer" LOL
Marriage standards
I don't wanna be an electrical engineer, I just wanna got some questions right on the test I'm having tomorrow.
RT
i hope you did well on your test
Five YEars Later -> How'd u do on the test?
@@hey9530 Well, I graduated high school without any problems. The video was helpful!
@just some guy tired of life Yessir.
Real-world wires have resistance, but in the diagrams, we assume that the non-resistor part of the circuits have no resistance (or that it has all been added to the "resistance" in the diagram)
If there was perfect conductor wire and no resistors at all. Does that mean that the voltage between any 2 points is equal to 0? But that makes no sense since each battery has some Nonzero voltage
"If there is any such thing as reality"
Sal's having another existential crisis :P
"For fun let's put in a third resistor"
Me: "whoa! U wild"
"but what we know in reality what is happening, if there is such a thing as reality..."
sal, you're awesome.
I love that Sal managed to slip in a little philosophy while he was at it.
you can't really do physics well without philosophy
4:58 Hey Sal, thanks for all your teaching and sharing, so here is my small contribution: Electricity in a wire moves at 2/3 of speed of light, electrons move very slow :)
U learn something new every day 😊😊
OMG this is so simple. When my professor explained this part it sounded so damn hard. I wish you were my professor :)
Btw, thanks a lot for these videos.
we all wish he were our professor :'(
So, i used Khan academy all last year when i did my basic introductory course in medicine. now, i am doing physics and chemistry to hopefully enter medical school...
and didnt you know, Khan can help you in physics as well!
THANKS!
good luck!
i got accepted! i also got exactly the stuff in this video, in my physics exam. talk about coincidence
***** wow good job, I hope I get accepted too. Have a great college period!
His voice is so relaxing :)
Hahahaha
"It's my wife, she'll probably mind that i didn't answer but anyway...."
haha love the dedication
0:48 deep
Yeah
After watching 6 minutes of the video I just wanted to say that you are AMAZING at explaining things. You make everything so easy to comprehend
I think the amazing thing about your videos is that I understand everything you explain.
This is something I rarely experience in school. xD
He is such a good teacher. I literally came here knowing nothing about circuits, and after watching this video I somehow am completely ready to complete my lab work. Now the work suddenly seems so easy.
Kahn academy is very helpful, in fact I watched this video to clarify some my knowledge on circuits because my physics teacher was unclear. However, in a battery, the electrons do in fact flow from the end known as "positive". This may be confusing at first but the reason that it is denoted this way is because that is the side with the higher electric potential energy (the side with all of the electrons, so it actually does flow from the positive end to the negative end). Other than that, this was a great video. I just wanted to clarify
Sal is the man.
I attend university in Victoria, Australia, and one of my classes is Electrical Systems.
The lecturers are very smart but they forget that many students haven't dealt with the basic concepts of electrical functions, and tend to skip over them.
I'm 12 weeks in and about to sit my exam, and before seeing these videos I was really worried. But SAL MAKES IT SO F***ING CLEAR.
If I get a pass, it's due to Sal and Khan. Thanks man!
Did you pass though
@@greenscreenasshole I actually did!
@@mitch3850 congrats!
thank you very much. i totally have a different view on physics. its actually easier and more sensible than i thought. thank you
I'd like to initiate this comment with a huge THANKS to you Mr Khan, you're a genius!
Second, I'd like to contribute with a personal idea, to people who have a hard time with understanding some basics when it comes to circuits, like I used to have.
Why is it so that the voltage over the "more powerful" resistor is higher than the other. Well, voltage is defined as energy/charge. It requires more energy to get pass the big resistor than the small, simple. Over and out.
I know you guys think this guy is the best teacher but what I'm about to say is different
THIS GUY JUST EXPLAINED THIS TO ME PERFECTLY, SOMETHING MY TEACHER COULDNT DO FOR A MONTH.
Man! Whoa Sal! 'If there is anything such as reality'-words of a legend (going through an existential crisis)
thanks man I wish u were my physics teacher
I'm just starting on this path with electronics, so naturally I count on Khan to set me straight. But this is a little confusing as laid out. First, sure, label the battery output terminal + (as in, adding electrons here) but perhaps denote that the + terminal is negatively charged (neg.) because electrons are negatively charged. And just don't label the other terminal.
Second, as I understand it resistors convert electrons into heat and radiate, so electrons are actually being spent by the circuit, and that is why the current drops. Correct me if I misunderstand this.
Also, correct me if I'm wrong that: The potential difference (voltage) is the same across the entire series circuit, only the load is dropping, and smart DC power supplies will only feed the required amperes (for the given voltage) to power the circuit.
THANK YOU FOR THE CLOSED CAPTIONS! :D It's great for hearing loss and to check if you miss something! :D
I would honestly rather listen to these videos and just go to class on test days than having to sit through mundane class after mundane class...learning nothing. You are a life saver Khan!
I know this is 12 years old so you’re probably not going to read this, but what helps me understand that the current is constant is to think of electrons as cars and the circuit as the road. At each “resistor” in the road, the speed limit decreases by a certain amount. So the bottleneck of electrons is analogous to bad traffic. The main difference is that electrons don’t “travel” along the wire like a car travels on the road; meaning that the instant you turn on the circuit, the current is constant. You don’t have to wait for the electrons to “travel” to each resistor, creating a bottleneck and then having it slow all the previous electrons down (which is what happens in traffic).
I love how y'all maintain retention by being friendly and sometimes amusing
Lol I didn't know that he made videos on circuits. These, especially Kirchhoff's Laws really kicked my behind last semester. It's mostly because our professor was under the assumption that we knew circuits well before entering his class. I did but I'd forgotten most of the things.
"when resistors in series we just add them up" YOU COULD'VE SAID THAT AT THE BEGINNING. But the explanation did help fix my curiosity
should have answered the phone man
Sal is the Bob Ross of Science.
Sal is the guy talking, Khan is the academy he represents.
You really have a way with teaching, as I am sure you have been told many times before. Thank you
@jaskaransingh because the battery is separated in a cathode(negative) and an anode(positive). There is a material between the two that has a higher resistance than the battery's voltage(basically the electrons are too weak to move through it). So the electrons can feel the force between the positive and negative terminals but they don't have the power to move. BUT when someone puts a wire between the two terminals(anode and cathode) the electrons can now move
0:48, from that moment to this moment, i'm living in existential depression...
I think its cool that really nothings real
But dont worry bout it STRAW BERRY FEILDS FOREVER
i like this khan academy..
its awesome.
This guy is so f*king genius. Love to learn from Khan academy. They are the gems.
I believe total resistance in circuits are the following:
In parallel circuits, the 1/R1 + 1/R2 = 1/RT (RT = Resistance Total)
In series circuits, the total resistance is just the sum of all the individual resistors: thus R1 + R2 = RT
Hope that helped.
A correction at 4:55. Electrons do not move at the speed of light through copper wire. Inside the wires, electron moves very, very slowly, almost as slowly as the minute hand on a clock. Electric current is like slowly flowing water inside a hose. Very slow, so perhaps a flow of syrup. Read more: amasci.com/miscon/speed.html
This gentleman is an excellent teacher !!!
khan your voice is also a + point for your explanation
tanks! this video is awesome!
thanks again sal! you mentioned a lot of small but important details which my physics teacher didn't mention (or perhaps I missed them because I was sleeping =), which really helped me understand this better! thanks!
Funny thing about the video is that in part 5:20 you say that electrons cant slow down just before the pass through the Ressistor.Thats not very right
Well physics is so harmony that can allow that to happen xD
think about it...if they slow down they compressed so they become a big minus charge in that area of the Circuit.
Result? they slow down the upcoming electrons and in same time they push away on the other diraction the other electrons!!!
Love physics ^^
I love it how he pauses to think how to put things in layman's terms.
"if there's any such thing as reality" i've never seen a prof. get more specific when setting a premise.
will after the first tow videos I felt more comfortable because I could understand something now. I will contenw watching them and I hope that I will get A on my upcoming MT.
Thankj you, this video is really good, i undestand more about the series Circut now, and about the Volt Drops on the eacht resisters.
I didn't understand why the current is the same and why the total voltage is the sum of all the voltage drops. I don't like expiremental proofs that is why I am so confused. Pls answer
I liked the video. He is a very good instructor!
I love this guy! circuits + comedy = priceless
Electrons don't move across the circuit anywhere close to the speed of light. Their motion propagates at the speed of light. So when the first electron moves it takes the last electron to move as much time as it would take light from the first electron to reach the last electron across the circuit.
Very Helpful.Thank you
"if there is any such thing as reality" 0:46 - Classic Sal
Sal,you are the man. Thank you.
Sal has taught me math through calculus, organic chemistry, and now physics
@xDivineForYou, Well you are correct that electrons flow faster than a few inches per hour (!), remember that electrons are pushing on other electrons in the cable, and the light would turn on almost instantly anyway. Think of it like a hose full of water that is just turned on. Of course the flow of the water isn't terribly fast, but the water that is currently in the hose is pushed out immediately, causing a seemingly instantaneous flow of water. Same deal with electrons. :)
This video is great!!!
18 people were amish
Yes, if the material is above its critical temperature it's not a superconductor.
This was a very good video!!! Great explanations
If Sal ever has kids, they will be all-knowing!!
@69elchupacabra69 Electrons move very fast. But the reason the current moves so slow is that the way the current flows, is that one electron bumps into another. So imagine that in a tiny bit of wire there are 1000 electrons. The electron that comes into the wire bumps into the first one, that bumps into the second one, and it continues that way until it reaches electron number 1000. In all of that time it took these electron to bump into eachother, only 1 electron made it's way out of the wire.
I love you. Seriously. MUCHO LOVE FROM GEORGIA IS BEING SENT YOUR WAAAAAAAAAAAAY!
Could someone please tell me what exactly causes the potential drop when charges across a resistors?
great video!! thanks so much
This is great thank you!
Nice job. Really im a university student but there in class is so boring and rabish lecture. Thank u, we looking forward to see more videos.
So does the voltage change in value after each resistor?
If we for example have a circuit with a Voltage Input and voltage Output, with a single resistor in between, would the voltage input be the same as the voltage output? Or would the resistor change it's value?
Is there any such thing as reality? That, my friend is a very good question.
@xDivineForYou @69elchupacabra69 electrons do flow very slowly. "For a typical metal, n = 10^28 m^-3, if the current is I A in a wire of cross-sectional area 10^-6 m^2 (a typical wire), we find v = 6 * 10^04 ms^-1. This is quite a LOW SPEED. If we turn on teh switch for the lights (5 m away), we certainly do not wait 139 min for the lights to come on! This is because , when the switch is turned on, an electric field is established within the wire. This happens close to the speed of light."
So will the total resistance or actually the way of funding the total resistance be the same for a parallel circuit?
Would electrons not bunch up due to "like charges"? Thank you this video helped a lot.
Good day,khan academy! May i ask where to ask permission to use this video for my research study. Thank you!
I don't want to become an electrical engineer, I just want to give my best in NSO exam
Sir according to the ohms law V=IR voltage is directly proportional to voltage so there is voltage drop in circuit due to adding resistors but current is constant through out the circuit why ?
Ha ha 'Oh oh its my wife she will mind if i dont answer but anyway' Ohhhh you are brilliant Sal!!!
Funny and brilliant
You know a video is interesting when you dont look at the time once,thats what happens with all of khan's videos !
Best explanation👍
I have a new religion called "Salmankhanism"
I'm honestly just learning this so I can make circuit boards for music boxes. My brain is gonna hate me
How is this guy so damn smart??
i've learned that electron in a circuit cannot move at the rate of light. a lot of electrons in conductor just move at the same time when pushing the electric force. Im confused in that point.. i want to know the theory accurately
10:02 we litterally both thought of the same numbers lol
Video and explanation is too good but it was a little bit difficult to understand. The speaker here should speak more clearly. If the speech isn't clear the listners won't be able to understand what the good is speaker wants to deliver. Pls pay a kind attention to it.
A kind advice😊
Thank you for all ur videos ! Excellent videos for the betterment of students. Thanks guys !
But according to Ohm's law current is directly proportional to the potential difference. So when the potential difference decreases shouldn't the current also decrease along the circuit. How can it remain constant?
great videos!
I love Khan Academy
I have a question is the Current always constant everywhere on the circuit? or just in the cable not going through resistors?
is the voltage constant throughout the circuit or is there a different voltage at two given points around each resistor?
this video changed my life
Same bro
dude who are you?
it's a me. mario
electrons actually travel very slowly, but since a lot of electrons are moving throughout the wire the effect is very fast.
@arkdude211 Me too! I swear my teacher doesn't understand physics. Today, my class decided that this girl in our class knows more physics than our teacher does. :D
Watching this video (and part 1) and writing notes on them was my physics homework tonight. Thank god! Khan, you saved my life, I think I'm starting to really understand this concept now. :)
yes, they travel slowly. The reason why its fast, that its going in waves
why dont the electrons just get to the +ve side through the battery , why all the way long and then ?
That's what you get for camping!!
When you say that the current is constant throughout the circuit, does that only apply for resistors in series or also in parallel? Is it constant always?
When Resistors Are In Series Just Add Them Up - Sal Khan 2008
@liamlovespie i accept it! :) this is well spelled and easier to understand than my version... sorry for the quarreling.. :)