00:01
Hi, according to the kirchhoff's voltage rule, the sum of voltages across any loop must be equal to zero.
00:10
So if we are looking at the biggest loop, which includes r1 and r3 only, we are only going to go to the outer loop, if you look at the figure in the problem.
00:23
Then we have delta v is equal to delta v for the r3 for the bottom resistor, plus delta v for the r1 for the top resistor, must be equal to zero.
00:39
And we are now moving clockwise.
00:41
If you think, if you look at the figure, when we are moving clockwise along i1, i1 is in the same direction as our movement across r1.
00:54
And that would result in negative i1 r1.
00:59
There will be a voltage drop, minus i1 r1.
01:03
And if we are looking at r3, we say that as we are moving clockwise, we are going against the current i3...