Hi friends, In this video we are going to See the most fundamental law in electric Circuit and that is kirchoff’s current law, Also known as KCl. Law states, algebraic sum of all electric currents Meeting at a junction or a node is equal to zero. So I repeat, algebraic sum Of electric currents
Meeting at a junction or you can say a node is equal to zero. So in this statement two things we have to be clear, One is what is the meaning Of algebraic sum and second what is the Meaning of Junction and anode, so to elaborate this let’s consider simple circuit. I am considering this point as a node Or a junction and some branches are Connected to that so some branches are Meeting at this node so for this Branches I will give a random value of current, In random direction. So I consider five branches meeting at a point A, having i1, i2, i3, i4, i5 and The directions of current I have Mentioned randomly. To elaborate the Concept of incoming and outgoing current We need to make sure that some of the Currents are incoming to that point and Some of the currents are leaving. So, I need to have some notation to define that So for incoming current, I will consider those currents positive. Positive value current and obviously Other is outgoing currents, I will consider those currents negative. Negative value I will take into account So incoming current, for this I am having, i1, i3 and i4, so (i1+i3+i4) Incoming currents having the positive value Plus because I need to do some Outgoing currents I have considered a Negitive So here there are (-i2-i5) So I have considered a sign Along with a value that is the meaning of algebraic, And sum I have taken, a Summation of these two currents as per the law This should be equal to 0. I further simplify this expression and I will get (i1+i3+i4)=(i2+i5) Now I am generalizing this statement. i1,i3,i4 are all incoming Currents, so generally I can write Summation of all incoming currents, Equal to summation of i2 and i5 are outgoing currents, So in a circuit if there are n number of branches, Connecting to a node I could generalize summation of incoming Current equals summation of all outgoing Currents. Actually I am considering that whatever charges Are incoming for this node same Charges Are outgoing. So ultimately KCl Can also be considered as, Conservation of charge. This is one of the most fundamental law along with Ohm’s law, That you are going to use to solve a Certain numericals, And it is applicable at any circuit of Electronics,electric so it’s one of the Most fundamental law in electric field. Thank you.