00:01
Consider this circuit where the value of r1 is given as 14 oms, r2 is given as 4 oms, this r2 is also 4 oms and r1 is 14.
00:12
So we have to find a potential difference between a and b.
00:15
For that, i think let's just find the equivalent resistance and hence the current.
00:20
Because if we get the current in this branch, we can easily use the what do you call it as, we can easily travel from a to b and get the potential difference.
00:31
Between them right so the equivalent resistance these two are in cds so their equivalent will be 4 plus 20 which is 24 ooms and then the equivalent circuit is gonna look like this right one two and three so this is 24 this is 4 and this is 14 so this 4 14 and 24 are all in parallel right so they are all in parallel it means that we can replace it with another equal resistance let's call it r this is already 14 and this is 25 so this value of r we can find using mathematically by the formula that 1 over r is 1 over 14 plus 1 over 4 plus 1 over 24 so i think that's where my calculator comes in so let me just do that 1 divided by 14 plus 1 divided by 4 plus 1 divided by 24 and remember to take the reciprocal of that value as well so resistance is coming around 2 .75 oms up to 2 decimal places.
01:45
And what is the current now? current we can easily find, right? because current will be in this direction.
01:49
So the current is voltage or the net resistance.
01:52
And now these two are in c .d.
01:54
So that will be 2 .75 plus 14.
01:57
So if we add 14 to it and 25 over this value comes out as 1 .49 amper.
02:06
This is the required current.
02:07
But we don't need current.
02:08
We need the potential difference.
02:09
So we can easily get the potential difference between a and b.
02:13
We travel from b to a like this.
02:15
So we travel from b to a, then we'll get va minus vb since the final point is a and initial is b.
02:23
We are traveling from positive to negative over here.
02:25
So that's negative.
02:27
And the current is directed over here.
02:29
So it is over here...