00:01
In this problem, in the electric circuit diagram below, calculate the equivalent resistance rab and then use it to find current i.
00:14
Right.
00:15
So for that, all right.
00:22
So we now need to convert here this y form in delta form.
00:26
So let us say this is this is converted like this.
00:30
Okay.
00:31
Here will be one register.
00:33
Then we will be having one register here right in this way it will be made okay so here let us say this is r1 and this is r2 and this is r3 right so we will convert here so here 5 and 10 are there that means 5 into 20 then 20 then 10 into 5 we will add these 3 and we will divided by 20 because this is made with 5 and 10 r1 is made with 5 and 10 that's why we are dividing by 20 so you can remember it from y to delta transformation how to do so similarly we are doing for r2 and r3 so we will be getting the 17 .5 35 and 70 respectively for r1 r2 and r3 values.
01:34
So how will be that circuit will be looking like it will be looking like this is plus minus here it becomes like this and we have one more resistor here that is r1 right and here and here we have one resistor here right so now this is also one resistor one more resistor is there here so this is 120 volts and here we have this r1 r2 and r3 right and this is what this is 30 old and this is this is 125 own so this is also 15 oad so what this is 12 .5 old so what this is 12 .5 125 what is written there that is 12 .5 ome right so this is 12 .5 om and this is 15 o all right so how can you differentiate here which is in parallel and which is in series so this potential is same and this potential is same so for this register right so that means for 12 .5 and 12 .5 and r1 you can say that they are in parallel.
03:16
Similarly for r2 and 15 oom resistor, you can say that they are in parallel, isn't it? so in this way, you can find it out.
03:28
Okay.
03:29
Now, let us just calculate the value of equivalent resistance.
03:36
If you just solve this to these two, right, r1 and 12 .5 and r2 and 15 oom.
03:46
So what you will get you will get somewhat a circuit in series so what will be that let us calculate 17 .5 into 12 .5 this is basically divided by 17 .5 plus 12 .5 so that must be equals to 7 .291 right yes so that is not 125.
04:23
That is you can say that these us that is 12 .5 value is 12 .5 here.
04:31
So it becomes equals to this is basically 17 .5 multiplied with 12 .5 divided by 17 .5 plus 12 .5.
04:45
So this will be giving us what? this will be value will be 7 .29...