Nodal Analysis Example Problem #1: Two Voltage Sources

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  • čas přidán 23. 07. 2024
  • This tutorial works through a Nodal Analysis example problem. Nodal Analysis is a method of circuit analysis where we basically just apply Kirchhoff's Current Law (KCL) at each node with an unknown voltage. You can choose to ground any of the nodes, but generally, grounding one with the most branches (especially if they are voltage sources) will make the problem easier. We will end up with one equation per unknown node voltage, and can just solve the system of linear equations to find the branch currents. This example problem features two voltage sources.
    This video is part of a full free course on electric circuits. The course covers DC circuits, circuit laws, current & voltage sources, series & parallel resistors, nodal analysis, mesh analysis, and AC circuits.
    Links to the course are here:
    Website: www.engineer4free.com/circuits
    CZcams: • Circuits
    If you found this video helpful, then please give a 👍 and subscribe. If you're able to, please support my work on Patreon: / engineer4free
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    Thanks for watching, I hope it helps!

Komentáře • 86

  • @Engineer4Free
    @Engineer4Free  Před 3 lety +7

    Scroll up and hit that 👍 button if you found this video helpful!
    Full Circuit Analysis playlist is here: czcams.com/play/PLOAuB8dR35ocf9Typ1iX9NRmX0V04UYfQ.html

  • @isaacmwangi7038
    @isaacmwangi7038 Před rokem +56

    Thanks, though you have made a mistake at kcL B , because if you multiply -4(2-vB)
    You are supposed to get ( -8+4vB)
    So that you get =2vB-VA+vB-8+4vB
    If you solve further you get vA=7vB-8

    • @stacybatabe3843
      @stacybatabe3843 Před rokem +8

      Thank God i wasn't mistaken

    • @siul2
      @siul2 Před 7 měsíci +1

      bro no wonder I was so confused

  • @bexleynessia7114
    @bexleynessia7114 Před rokem +5

    I hate long video tutorial and yours is just so brief and simple easy to understand and fast to learn a big topic in less then 10 minutes thank you for this so helpful

  • @spoon4974
    @spoon4974 Před 8 měsíci +3

    This one and the explanation made Nodal analysis so much more understandable

  • @md.abdullahalrafi6496
    @md.abdullahalrafi6496 Před 2 lety +46

    100x better than my university teacher.

  • @santucigod
    @santucigod Před rokem +3

    Totally amazing. I really could understand thanks to you.

  • @antoni3071
    @antoni3071 Před 8 měsíci

    You do amazing job! I am going through the playlist and smashing like on every video, cuz you deserve some positive feedback for this work

  • @IceBelly
    @IceBelly Před 2 lety

    Thanks for this video , my guy saving my assignment rn

  • @ChiefYOUtuber
    @ChiefYOUtuber Před 2 lety +61

    7:02 For the second KCL you did an algebraic mistake. It is not +4 but -4

  • @user-wf6iq5se8p
    @user-wf6iq5se8p Před 9 měsíci

    TQ for this sir..I am able to understand ur calsses easily

  • @user-kj3nv4mr1s
    @user-kj3nv4mr1s Před 2 měsíci

    Life made simple thank you very much.. very simplified

  • @sarathybhaskaran7957
    @sarathybhaskaran7957 Před rokem +4

    This guy made my day, and now i can teach my girlfriend!
    You get a subscription.

  • @umairawan658
    @umairawan658 Před 4 měsíci

    Much informative vid keep it up👍

  • @wesleytissmah6516
    @wesleytissmah6516 Před 4 měsíci

    Thanks understood clearly ❤

  • @almiaangelol.9059
    @almiaangelol.9059 Před 2 lety

    Hi how to solve if the 2 ohm's is unknown?
    Hope you notice

  • @micahjessy4736
    @micahjessy4736 Před 2 lety

    Thanks for this video

  • @jamaicagonzaga7887
    @jamaicagonzaga7887 Před 2 lety +2

    Sir thank you so much, you saved my day....I already subscribed your channel....Thank you and God Bless

  • @shizaalmas
    @shizaalmas Před 2 lety

    Exellent .i visit a lot of channel bit your channel is best .you solve my confusion

  • @siddharthpg2919
    @siddharthpg2919 Před 9 měsíci

    thank you so much !!

  • @kennethkngoma1262
    @kennethkngoma1262 Před 4 měsíci

    Wow, Thank you so much

  • @tomitonaomy9666
    @tomitonaomy9666 Před rokem

    Wow 🎉 thanks so much

  • @mohammadhoseinrivandi5657

    Hi,I have a problem and i can't solve it.Is there a way to send the problem so that you help me out?

  • @amandragon8919
    @amandragon8919 Před 6 měsíci

    But how do you get KCL A -6 to -18 after simplify? may i know?

  • @nusratnoor8440
    @nusratnoor8440 Před rokem

    May God bless you 🙏❤ bro

  • @mars8499
    @mars8499 Před rokem

    Your voice is soothing

  • @noelleemma3043
    @noelleemma3043 Před 2 lety +11

    -6 *-Va is +6va

  • @electriccircuits19
    @electriccircuits19 Před 2 lety +3

    *“We learn more by looking for the answer to a question and not finding it than we do from learning the answer itself.”*

  • @onyxtechnologyx
    @onyxtechnologyx Před rokem

    I love u so much dude

  • @atiqnajmi1163
    @atiqnajmi1163 Před 2 měsíci

    Nice video

  • @kozuta8858
    @kozuta8858 Před 9 měsíci

    what if the voltage source is flipped and negative sign is above?

  • @nacht3894
    @nacht3894 Před 8 měsíci

    Thank you sir

  • @cosmos8366
    @cosmos8366 Před 2 lety +5

    I like how you used the fraction multiplied by 7 for less rounding issues

  • @tormentor2285
    @tormentor2285 Před 2 lety

    love you man

  • @lagunacorona
    @lagunacorona Před rokem

    I dont understand why i3 on one side is traveling in and is respresented as a positive ? and on the other set on node be as a negative ??? what is going on??

  • @FatimaZohra-hn3vi
    @FatimaZohra-hn3vi Před 2 lety

    What if we have only one voltage source

  • @user-vu1kg6nq4c
    @user-vu1kg6nq4c Před 8 měsíci

    How to know the currents are out or in in direction please reply me soon

  • @lagunacorona
    @lagunacorona Před rokem +2

    Can you do one based on wheatstone bridge? also it seems from other comments on other videos that professors leave specific details out to "appreciate how to get the right answer" people don't have time to mess around.

  • @user-yg4fn3zy6s
    @user-yg4fn3zy6s Před 4 měsíci +2

    In NIGERIA, lecturers don't teach. They just give course outlines then ask you to go study yourself with brief explanations.

  • @merrysanjenbam603
    @merrysanjenbam603 Před 3 lety +5

    Hi, I like your teaching but i have one doubt in this video. I want to know why i3 goes on right side? can't it go to left too? Please reply! much appreciated

    • @Engineer4Free
      @Engineer4Free  Před 3 lety +7

      I just assumed a direction for i3, in this case it was to the right. When I drew it, it was an unknown, and I could have assumed either direction. If i3 ended up being a negative vale, then that would have told us that it was in fact pointing the other direction. However, in this example, we calculated i3 to be positive, so our assumed direction was correct.

    • @merrysanjenbam603
      @merrysanjenbam603 Před 3 lety +1

      @@Engineer4Free Thanks a lot . Subscribed your channel. I hope your channel will help others a lot too Keep it up

    • @HardwareNinja
      @HardwareNinja Před 2 lety

      Hi Merry,
      If you're interested in electrical/electronics engineering, we're building a channel to help students and professionals prepare for job interviews with real world questions. We'd love it if you could swing by. Also, our LinkedIn is: www.linkedin.com/company/hardware-ninja

  • @AlexTheTech
    @AlexTheTech Před 5 měsíci

    5:05 Its supposed to be -18+6va, because negative times negative becomes a positive.

  • @ankitnigam4261
    @ankitnigam4261 Před 2 lety +2

    at kcl b the final equation is wrong

  • @mightygod-bw3cn
    @mightygod-bw3cn Před 2 lety

    4:11 how to you know what to multiple with like when u did with 12

  • @user-pn8my5ix4u
    @user-pn8my5ix4u Před 11 měsíci

    Erm how is -6x-3va still a -18va at kcl A

  • @Incomplete_artist
    @Incomplete_artist Před 3 lety +1

    How we find common dinominator?

    • @augustussinclair1626
      @augustussinclair1626 Před 2 lety +3

      it's quite easy, actually! it's elementary level maths; basically you single out all the numbers on the bottoms of the fractions, line them up and start dividing with numbers in hopes of getting each number to a 1.
      for example, if you have 1, 2, 4 like in the Vb portion of the video - you ignore the 1 because it's already a one, so you have 2 and 4 left. both are divisible by 2, which - when divided - leaves you with a 1 and a 2.
      then you divide them again with a 2 and the end result is three ones, with two twos you used to divide them with.
      then you multiply the numbers you used while dividing (aka 2 and 2 here) with one another, and the end result is your common denominator (4 in this case).
      hope i was able to help!

  • @cosmos8366
    @cosmos8366 Před 2 lety +35

    In KCL - A you multiplied -6 by -va which you have as -6VA which should be +6VA . If it was -6VA you would not have 13VA but instead just have 1VA.. to get 13VA it has to be positive.

  • @seth2039
    @seth2039 Před 2 lety

    huge

  • @officialfayomi
    @officialfayomi Před 11 měsíci +1

    Am i the only one who noticed that he made a mistake in KCL B, while subtracting I5 from I4 and I3. He changed I5 sign from minus to plus.

  • @zackify187
    @zackify187 Před rokem

    why is it not -va + 7vb = 8

  • @Pragmatic80
    @Pragmatic80 Před rokem +1

    I'm boggled a little bit on 7:51
    How is 2VB + VB - 4VB = 7VB
    Shouldn't it be -VB?

    • @zackify187
      @zackify187 Před rokem

      VB counts as 1. Same as how X counts as 1.

  • @adriang.batarabsee3c363

    What happened to 7Vb?

  • @nixnocar9004
    @nixnocar9004 Před rokem

    to come up 13Va

  • @rpain-tt9dp
    @rpain-tt9dp Před 8 měsíci

    you should use mesh hhere

  • @nixnocar9004
    @nixnocar9004 Před rokem +1

    i think that -6Vb is +6Vb

  • @nixnocar9004
    @nixnocar9004 Před rokem

    sorry the -6Va i mean is +6Va

  • @AniMedicine737
    @AniMedicine737 Před rokem

    Is it just me or he change the KCL at I⁵

  • @kristoffermeyer8339
    @kristoffermeyer8339 Před rokem

    The results are wrong i'm afraid. You made sign destribution mistake in the sign distribution in KCL A and B.

  • @faziltaftani8250
    @faziltaftani8250 Před 7 měsíci

    Which one of you guys student at university of lahor
    Our sir is wallhi azab😶

  • @micheletjean-charles9966
    @micheletjean-charles9966 Před 2 měsíci

    VB should be 1.32v

  • @mimiizabil4519
    @mimiizabil4519 Před 3 lety +2

    ماتقدرش تهدر عربي

    • @mahadomar3089
      @mahadomar3089 Před 2 lety

      ابحث عن عربي دي انجليزي.

  • @joeaberman449
    @joeaberman449 Před rokem

    minute 7:30 big mistake does not correspond to previous level throw you out of loop!!!!!!!!!!! review review

  • @VRS876
    @VRS876 Před 8 měsíci

    Don't put this type of videos

  • @mimiizabil4519
    @mimiizabil4519 Před 3 lety

    Speak arabe