00:01
All right, so in this problem, find the thevenin and norden equivalent circuits for the two terminal circuit shown in figure.
00:12
Right.
00:13
So here the figure is given to us, right? and circuit diagram i will draw here in this only.
00:21
With black it is given to us, but i am writing here.
00:25
Let us suppose v1 as a terminal here.
00:29
Right and here vth is nothing but this is a thavenen voltage we have just assumed because we want to find out the tavenin equivalent equivalent circuits as well right so all right so now applying kirchhoff's current law at the node v1 can we apply here yes so here it becomes this let us say this current is going like this this current is going like this and this current is going like this, right? so, on the current which are going like this outwards, we are taking it as positive only, right? so here, what will be the potential difference between this branch, this and this branch from here with, you can say from this and this, you can say voltage source.
01:23
So it will be v1 minus 32, right, upon 10, right? so this is the resistance, right? so that will make a current.
01:33
That is how we do in the kirchhoff's current law.
01:37
Yes.
01:37
So now what will be the current for the other branch? for this branch you can say right this branch.
01:46
So for this branch it will be v1 by 10 right because here potential is zero here.
01:54
Can you say this? so v1 minus zero we are not writing again zero here.
01:59
So that will make v1 itself right.
02:02
So that's why we're v1 by 10 all right plus v1 by 15 plus 30 right so difference between this branch and this branch directly we are taking this way so this will be equals to zero here all right so now moving forward when we solve this right so we will be getting we have to solve this we will be getting v1 as equals to 14 .4 volts right so this voltage we have got right so first of all we have to calculate tavanese voltage then tavenance resistance then we will make a circuit for that so that is also so simple as that we make that equivalent as like this this should be r t h and it should be a voltage source right where this is considered to be vth all right so now um we have just found out the value of v1 here in our circuit right so here this should be vth okay i have represented it okay now moving forward we will find it find the thabinian's voltage using voltage division rule here right so vth is here right and we will find for so this will be voltage of vth will be in this branch right this is the voltage difference here for vth right so here it becomes we want to find out for 30 that means for 30 om it will be 30 by 15 plus 15 plus 30 right so this is this is we are taking we are seeing from here right from terminal to the circuit right we are not moving from left to right here we are moving right to left here remember this this is very important part of thavinens finding the thabinine equivalent right so here is the current and this current will be flowing like this and this current would be flowing like this okay so that means two branches are available here that means from here you can see this is we can see 15 om right so that means the um we want to find for 30 om we want to find the voltage across 30 oh right so that means 30 upon 15 plus 30 right and total of v1 so what is that v1 we even from we have considered this as a voltage source for this 15 om right so we need not to take these all resistors okay what all registers 10 ohm register right so okay so now moving forward we can just find the vt hs here so we will just put the values we have calculated for v1 so this will be given by 30 by 15 plus 30 into 14 .4 that will be vtah will be equals to 9 .6 volts here right now to calculate the threvenin resistance we short circuit the voltage source first right right so this is the rule for this we have to short circuit the voltage sources in this circuit here right to calculate the thavenance resistance, right? remember this.
06:07
What is the thavenance resistance? thavenance resistance is rth, let us see.
06:15
So we will make a circuit diagram.
06:18
How we calculate is.
06:19
Again, i am telling that we will see from terminal to the circuit, right, and solve the rth, right? so we have short -circuited this voltage source.
06:31
Right so this is the circuit diagram we have got here now we will see from the terminal to the circuit and we will solve all the things right so here is the terminal right so this this branch that is 30 oam branch is parallel to other branches so now we will start solving from here so 10 om 10 om is to be parallel with each other right so that means if they are parallel then we can easily say that when resistance are same, then we can easily directly solve that 10 by 2 is the answer, that is r by n is the answer for parallel 1...