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Kirchhoff's voltage law | Circuit analysis | Electrical engineering | Khan Academy

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Күн бұрын

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@lihlezonela6377
@lihlezonela6377 7 жыл бұрын
khan academy is the legendary site my boy
@hossboi52
@hossboi52 5 жыл бұрын
ATTENTION: EVERYONE WHO IS ASKING ABOUT -20 VOLTS.... His equation Vrise - V drop = 0 is the equation for the whole circuit. On the left side, where the battery is, there is a 10V rise....on the right, where the resistor is, there is a 10V Drop...this is where he is getting 10(rise)-10(drop)=0 | That rise= -10 is, like he said, just another way of writing a drop. I understand the confusion, there is not much point of writing that unless he wrote 0=sum of voltage rise ... in which case that specific "rise" on the right would technically be negative due to the resistor, however that is often confusing and he just was using this as a way to get you to understand that this is a decrease in voltage. His math however is all correct.
@mstfarzanaakther8046
@mstfarzanaakther8046 3 жыл бұрын
Thanks a lot
@Rick-gd6pe
@Rick-gd6pe 3 жыл бұрын
By any chance do you know what the voltage is actually doing when it drops?
@brandonbennett4970
@brandonbennett4970 2 жыл бұрын
@@Rick-gd6pe the potential energy between individual electrons in the wire is dropping, meaning they are getting further apart. Because energy should be conserved in an isolated system consiting of the wires and resistive element, the loss in potential energy presents itself as an increase in heat (or light). This is a vast oversimplification of what actually occurs on the subatomic level and is not totally correct but it is a great way to think about it when first getting started, and will take you pretty far in electronics.
@L28PriyankarDas
@L28PriyankarDas 4 ай бұрын
@@brandonbennett4970 If the distance between two electrons is increasing, the potential energy of the system decreases overall,but why doesn't the energy comes off as kinetic energy? I mean shouldn't the speed of electrons in the system increase?
@brandonbennett4970
@brandonbennett4970 4 ай бұрын
@@L28PriyankarDasthe electrons collide with resistive material and lose energy. They don’t get a chance to increase their kinetic energy because it is lost as heat
@dannewlon5825
@dannewlon5825 7 жыл бұрын
Great review, had all this 40 years ago in college, but basics are always applicable.
@aselim20.
@aselim20. 5 күн бұрын
I watched it twice and I have taken notes in 2024-2025 1st semester.
@jasssa8635
@jasssa8635 8 жыл бұрын
the voltage directions are wrong so the numbers become wrong too. this is very misleading
@mahshidpanah8851
@mahshidpanah8851 3 жыл бұрын
Voltage drops across the components (resistors) are positive if a loop direction is opposite to the current direction
@curtpiazza1688
@curtpiazza1688 Жыл бұрын
Beautiful! 🎉 😅😊
@RR-ex2uv
@RR-ex2uv 7 жыл бұрын
Thank you so much for this video! I have been really struggling with understanding when voltage and amp sources are equated as being negative verses positive, especially when there is a mix of both in the circuit!
@stevenroberts3148
@stevenroberts3148 Жыл бұрын
QUESTION: I thought that the voltage throughout a circuit was constant. I'm confused by the whole "voltage drop" thing. Shouldn't it be constant through and after hitting the resistor?
@raheelbelal5848
@raheelbelal5848 Жыл бұрын
in series it drops, but in parallel it stays the same
@smgf-dm3zu
@smgf-dm3zu Жыл бұрын
No
@demonslayerer
@demonslayerer Жыл бұрын
I ain't no expert but from my understanding of volt, volt is just energy applied on charge to overcome the "opposing force" (Resistance). Or in other words force to get charges moving but force will be zero if there is no Resistance or charges are already moving, therefore if Resistance is zero either volt is zero (meaning charge need no force to overcome Resistance since it's already zero) or the current is infinite (which again means the same but this time it specifies that charges ARE moving).Resistance causes voltage causes current. So answer to your question, voltage isn't constant. (Correct me plz if I am wrong in anyway, i highly appreciate it.)
@L28PriyankarDas
@L28PriyankarDas 4 ай бұрын
@@demonslayerer sadly you are not completely correct,Your relation between resistance and volt(potential diff) is accurate,but in no way volt is energy required to overcome opposing force.Honestly i can not explain it here in the comments.
@snakes-and-ladders
@snakes-and-ladders 4 ай бұрын
Voltage is the energy per unit of charge. As charged particles pass through the components of a circuit, they will transfer energy to them. This results in a voltage drop.
@arfairfan9870
@arfairfan9870 5 жыл бұрын
Thanks a lot
@aboringuy
@aboringuy 4 жыл бұрын
Great video! Just one question: Will running two 12V fans in series off of a 24V power supply overvolt the fans? Or does the voltage have nothing to do with this equation?
@ChocoBaiterEUW
@ChocoBaiterEUW 4 жыл бұрын
has nothing to with that. do 12v to both.
@_aidid
@_aidid 7 жыл бұрын
(For 2:19) If I connect one voltmetre across the battery and another voltmeter across the resistor will the voltmeter across the battery show +10V and the voltmeter across resistor show -10V ?
@JustinHatter
@JustinHatter 7 ай бұрын
Thanks for the help!
@chandhnichowdhry2811
@chandhnichowdhry2811 5 жыл бұрын
Thank you... It was very helpful 😊
@leetcoder1159
@leetcoder1159 4 жыл бұрын
really?
@MOHTAHA2008
@MOHTAHA2008 7 ай бұрын
I did understand the concept, but I do have a question tho, does kerchhoff’s law mean that (theoretically) the delta V in every closed series circuit is equal to zero?
@steventodd5884
@steventodd5884 3 ай бұрын
Yes because they will all cancel eachother out. The net change would just be zero.
@samriddhi0906
@samriddhi0906 3 ай бұрын
thankyou!❤
@unknown-vq1gj
@unknown-vq1gj 6 жыл бұрын
If drop is 10 volts and rise is -10 volts. Formula V rise - V drop = 0; in this case -10 (rise) - (+10) drop= -20?
@harryiii3361
@harryiii3361 5 жыл бұрын
Those two values are referring to what is happening at the resistor, not the whole circuit. He was only pointing out that a drop of 10V is exactly the same thing as a rise in -10V
@medhatithidas5063
@medhatithidas5063 4 жыл бұрын
10 volt drop is same as -10 volt rise and you can also say that 10 volt rise is same as -10 volt drop. If you cosider it like this and the formula is that Rise - Drop =0 Then -10 - (-10) = -10 +10 = 0 Here I have considered 10 Rise as -10 drop and 10 drop as -10 Rise. It is quite confusing though but yes this is also a way how it works.
@abdeslamkabiri9392
@abdeslamkabiri9392 8 жыл бұрын
-10-10=-20
@gouenjigouenji7126
@gouenjigouenji7126 8 жыл бұрын
Good eyes.
@abdeslamkabiri9392
@abdeslamkabiri9392 8 жыл бұрын
:)
@fatimaafaf5740
@fatimaafaf5740 8 жыл бұрын
exactly!!
@abdeslamkabiri9392
@abdeslamkabiri9392 8 жыл бұрын
;)
@pn2696
@pn2696 7 жыл бұрын
I had that question too😏😏
@JamesDean-wv7iw
@JamesDean-wv7iw 9 ай бұрын
Sort of made sense to me, how I am suppose to get my head around KIV and KCL, I have no idea
@parasonu1
@parasonu1 8 жыл бұрын
what happens when charges move flat I mean why does potential drop occurs only at resistors? I mean when an electron travels from negative end towards the positive end it continuously loses potential so why we don't consider potential at flat areas where no resistors are present ?
@sherllymentalism4756
@sherllymentalism4756 5 жыл бұрын
VIKRAM SHARMA it's very low so we usually ignore it. Not always, however
@roycekimmel
@roycekimmel 2 жыл бұрын
That is covered in resistivity though for circuit design is often negligible
@yahyamohammed6729
@yahyamohammed6729 3 жыл бұрын
It makes sense that it's 5 volts in the middle node, but how do you get to 5V? Mathematically speaking
@СщькфвуЫефдшт
@СщькфвуЫефдшт 3 жыл бұрын
You can look at each resistor as a voltage drop. In this case 10 V between 2 resistors drops by 5 each time.
@andycoutts517
@andycoutts517 2 жыл бұрын
@@СщькфвуЫефдшт But why does 200ohms create a 5volt drop?
@alex3l4
@alex3l4 Жыл бұрын
​@@andycoutts517since the two resistors are connected in series, you can calculate the resultant resistance (R1+R2=200) and using Ohm's law (I = U/R = 0.05 A), calculate voltage drop by (U = R*I = 0.05*100 = 5 V)
@Inaflap
@Inaflap 8 жыл бұрын
@4:30 you suddenly changed the term from voltage drop to voltage fall. Otherwise this was a good video.
@gouenjigouenji7126
@gouenjigouenji7126 8 жыл бұрын
It's the same.
@gouenjigouenji7126
@gouenjigouenji7126 8 жыл бұрын
It's not a flaw
@dilkashaikh
@dilkashaikh 8 жыл бұрын
how to download physics playlist lecture in one times please tell me the procedure or name of software i want to all playlist videos in one times thank you
@swapnilg.5996
@swapnilg.5996 8 жыл бұрын
Khan Academy App
@HTCRAZYKWA
@HTCRAZYKWA Жыл бұрын
So does it always work in a manner that 100 ohms is always one tenth of the or is that just an example for the current equation
@3lxlDeMonlxl1
@3lxlDeMonlxl1 8 жыл бұрын
excellent video how do you do it?
@steveevets1130
@steveevets1130 4 жыл бұрын
"I'm going to arbitrarily call this 0 volts". Why? Ohms law says that the voltage there will be .05V. Is that not correct?
@akshatshah3925
@akshatshah3925 3 жыл бұрын
0.05A is the current, not the voltage.
@PatrickMoto97
@PatrickMoto97 4 жыл бұрын
Thanks bro
@СщькфвуЫефдшт
@СщькфвуЫефдшт 3 жыл бұрын
To clerify, the rise isn't a - based on the equation you followed? There's some conflicting values confusing me...
@pooffdk
@pooffdk 3 жыл бұрын
you can do one thing here and just use the clockwise technic it will be less complicated for you
@wisnuaimariyadi840
@wisnuaimariyadi840 3 жыл бұрын
far way better
@alexjag5778
@alexjag5778 8 жыл бұрын
Thank you
@dinsrock1
@dinsrock1 6 жыл бұрын
Hey, in 3:03 there is a error is guess, look, u have taken voltage rise as -10 and voltage drop as +10. The formula u told is saying voltage rise minus voltage drop=0 . If i substitute that " minus 10 minus 10 which leads to -20. Can u xplain on this.
@surajphaniharam8734
@surajphaniharam8734 4 жыл бұрын
Actually the rise is 10, look when it passes through volt meter and the drop is 10 as he said so that implies 10-10 which gives you 0 👍
@mahes9263
@mahes9263 3 жыл бұрын
Can someone give me a proof why the voltage drop should be the same as the battery?
@roycekimmel
@roycekimmel 2 жыл бұрын
The potential energy is exhausted over the path of the circuit much like lifting an object off the ground to increase it's potential then dropping it only for it to return to it's original potential (converting potential into kinetic energy for example)
@jwilham
@jwilham 4 ай бұрын
you need to explain why you are going from 10 volts to 0, and why you are going from 10 to 5 to 0. how unnecessarily complicated trying to explain rise with decrease of voltage.
@deepakkr.773
@deepakkr.773 6 жыл бұрын
Good
@hasibullah3902
@hasibullah3902 7 жыл бұрын
Y u no discuss complex circuits??I get stuck in the maths given in my book
@Tom-gc8ik
@Tom-gc8ik 8 жыл бұрын
Ok. Why did you "arbitrarily" name nodes with negative voltages? Is it with respect of the voltage in? And why does -10-10=0? Why is the node between the 2 resistors 5 ohms? Why does the voltage rise and drop in a circuit after sal showed its uniform all the way around? These are things that should be addressed. Instead of just saying this is it, you should leave the viewer with the knowledge of why this works and why it's useful. No intuition developed from any of your videos. I'm sorry. I'm sure you're a brilliant engineer, but when it comes to conveying your knowledge/intuition on a subject, not very good. Thanks for the effort though
@omega6872
@omega6872 7 жыл бұрын
That was the best way to put it !
@ombatra1000
@ombatra1000 7 жыл бұрын
That -10 is just to indicate direction .
@MyrahOfficial
@MyrahOfficial 4 жыл бұрын
Bruhh dude it was so easy and awesome ... honestly u just read once from a book, come back to it and then you'll see its fab
@michaelpiotto4988
@michaelpiotto4988 3 ай бұрын
voltage rise is not -10V, that make no sense. It drops 10V and then it drops again -10V. or it drops 10v and rises 10v.
@worldofmusic1058
@worldofmusic1058 4 жыл бұрын
I am a 13 yr old watching it so it is a bit difficult for me to understand this. Can you guys please help me at this?
@robbydiaz4922
@robbydiaz4922 4 жыл бұрын
yeah so what's your problem
@ajaykumarray8925
@ajaykumarray8925 4 ай бұрын
First grow upp
@IbnMeer786
@IbnMeer786 8 жыл бұрын
why we taken conventional current +ev to _ev??
@jebeccajamil
@jebeccajamil 8 жыл бұрын
although we know that electrons flow from -ve to +ve, conventional current is followed because by it makes the calculations much easier.
@insajderpapaj4650
@insajderpapaj4650 6 жыл бұрын
So complicated explanation of a sumple thing
@aselim20.
@aselim20. 2 жыл бұрын
I wrote it
@sebp400
@sebp400 2 жыл бұрын
he's calling branches, nodes? I'm learning and it's confusing.
@lihlezonela6377
@lihlezonela6377 7 жыл бұрын
ever had of LOGIC gate ntwana yam?
@subhashkale2654
@subhashkale2654 7 жыл бұрын
This is the most disappointing video of khan academy...... 😢😢😢😢😢
@talibqadri6403
@talibqadri6403 6 жыл бұрын
exactly
@archivvithlani6610
@archivvithlani6610 Жыл бұрын
it's such an easy topic?
@physicsclassofshamimsir8329
@physicsclassofshamimsir8329 6 ай бұрын
Ure being disappointing
@ZollMisc-c1w
@ZollMisc-c1w 2 ай бұрын
Thompson Jose Perez David Garcia Kenneth
@mohitchahal9476
@mohitchahal9476 7 жыл бұрын
couldn't understand...
@yawarkhan8309
@yawarkhan8309 5 жыл бұрын
Rise negative so_10_10=20 why u write 0
@TheRoxas13th
@TheRoxas13th 8 жыл бұрын
Why the voltage drops?
@salunkhesaurabh201
@salunkhesaurabh201 8 жыл бұрын
TheRoxas13th Volts is the difference of potential at two point ... so in battery we consider (-ve) as (0)volt and (+ve) as (V)volts
@loneventhorizon
@loneventhorizon 7 жыл бұрын
it didn't the current flows from - to +
@loneventhorizon
@loneventhorizon 7 жыл бұрын
america vs everyone else
@danieljoseph6404
@danieljoseph6404 7 жыл бұрын
because the total voltage in the circuit is 0 and theres only one resistor. so after it passes the resistor it would be 0.
@vomont
@vomont 6 жыл бұрын
Daniel Joseph what if there is no resistor. What happens then?
@hafizulsedutrik
@hafizulsedutrik 2 ай бұрын
কে কে মেডিকোর বই দেখে আসছো?
@Cloudfights
@Cloudfights 2 жыл бұрын
💯💯💯💯
@chaddonschaddons7084
@chaddonschaddons7084 6 жыл бұрын
Pretty badly explained because 'rise' has nothing to do with the perception of view, it has to do with the travel of conventional flow. Just to further prove this, imagine the resistor is sideways, left to right instead of up and down. There is still a drop on that resistor even though it's going sideways. The problem with this instructors explanation is that he is inferring that voltage is a sort of travel, but it is not gradual travel, it is explicitly a measure of the difference between two points. Here's where this video fails and it is the problem with the conveyance of the teaching.
@aizasaed170
@aizasaed170 7 жыл бұрын
where the hell has sal gone😟😟
@TheAlexsennin
@TheAlexsennin 5 жыл бұрын
Aiza Saed 😢
@MyrahOfficial
@MyrahOfficial 4 жыл бұрын
Ikrrr
@chriswoolson7352
@chriswoolson7352 6 жыл бұрын
This video was totally not correct. With different resistances, it is totally different
@hunterhunter109
@hunterhunter109 5 жыл бұрын
This video is really informative unlike half of those Indian videos which one can't even understand the language
@pamelabosworth433
@pamelabosworth433 2 ай бұрын
Martin Margaret Robinson Paul Anderson Barbara
@CarnegieDorothy
@CarnegieDorothy 4 ай бұрын
Lee Angela Perez Mary Johnson Lisa
@AldridgeSalome-e4e
@AldridgeSalome-e4e 3 ай бұрын
Williams Richard Jackson Richard Brown Deborah
@julianzzip3929
@julianzzip3929 8 жыл бұрын
Second
@shumailkhan7205
@shumailkhan7205 Ай бұрын
what a waste of a video
@blessyie643
@blessyie643 2 жыл бұрын
I hate math
@mohan4431
@mohan4431 3 ай бұрын
why
@hand_make_art
@hand_make_art Жыл бұрын
Sorry but this is very hard
@ethank.4103
@ethank.4103 Жыл бұрын
Why does he sound like Jonah Hill
@विसाजीदेशमुख
@विसाजीदेशमुख 8 жыл бұрын
bharat mata ki jai
@mr.osx3423
@mr.osx3423 6 жыл бұрын
To hell
@mustache2295
@mustache2295 6 жыл бұрын
Very useless.
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