Kirchhoff's Current Law

Introduces Kirchhoff's current law.

[gabrielborges]

That node explanation was great! Thanks a lot!

[DarrylMorrell]

You are correct. The current flow would still depend on the resistance of the wire, but would be much larger. In most circuits, the resistance of the wire is negligible compared to the other resistances in the circuit, so we ignore it. In some situations, like sensors connected to measuring equipment with long (> 20 ft) wires, we cant ignore it.

[DarrylMorrell]

There is a quantum mechanical/electrodynamics explanation, but I do not understand it well enough to explain it. In these videos, we are doing DC steady state analysis, so we give the circuit time to settle down from any transient effects that occur when voltage and current sources are connected and/or switches are thrown.

[DarrylMorrell]

@sruhan007 Thanks for pointing this out. The idea that current *always* chooses the low resistance path is another common misconception. More current chooses the low resistance path, but some current flows through the highest resistance path. The amount of current that flows through a path is inversely proportional to the resistance in that path.

[othmaan]

Thank you very much! I found your video extremely helpful.

[Diver]

Thanks for video. Very easy to anderstand explanation!

[DarrylMorrell]

Thanks for the heads up. I will correct it within the next few days.

[hawkar]

@DarrylMorrell I have a pretty random question regarding the path taken. How do the electrons know which path has the lower resistance without actually going down that path. Is the 'choice' instantaneous or is there a delay or is there some quantum mechanical explanation or am I just looking at the idea of current and flow completely incorrectly?

[Gilaskoram]

So I've got a question. You said that the current i1, i2, i3, and i4, depends on the resistor used. What if you didn't use resistors, would it then rely on the resistance of the wire itself. If that is the case would I be right in assuming the values of current would be quite a bit higher, as the resistance of copper is very low?

[adamdag]

oh dear thank you so much, after this video finally i got it

[qwertyuiop]

Am I correct in assuming that it wouldn't really matter which direction I decided to trace my path? What I mean is essentially: could I say i3=i2+i4+i1 and simply find the values that way?

[harkirankaur]

Hmm so this works same as using reciprocal of the reciprocals to add parallel resistance... then using Ohms law I came to same answer... I am only just starting to delve into electronics theory because I am starting a broadcast engineering program soon. But I assume there are times when you can only use Kirchoff's law and not Ohm's law to solve? But in the above case was I wrong by solving the current the way I did? Though I do understand the basic of what goes in = what comes out LOL.

[Srujansujju]

i d like to add another sentence at 11:18, " current always chooses low resistance path" :)

[emmuteelas]

@DarrylMorrell thanku so much...
but iam so thankful that just thanku doesnt cover it!
ur awesome!
:)

[Srujansujju]

@DarrylMorrell sorry, even i wanna tell the same :) n thanks for awesome lectures :)

[TheWrencher]

Ummm never explained the outcome of zero, you just used ohms law at each resistor and added it up