0:00
Hi there.
00:01
Here we have to rank the light bulbs according to the brightness.
00:11
So basically it means that we have to rank them according to the current which is flowing through those light bulbs.
00:20
So first of all, we have what we have to do.
00:22
We have to calculate the equivalent of total resistance of both circuits.
00:29
So let's start with the one on the left.
00:33
So here, yeah, here is a total resistance can be calculated as following.
00:42
That equals to 2r, 2r0, which is the resistance of each individual lamp times 3r0 divided by 5r0.
01:00
So that equals to 1 .2 r0.
01:16
So now, so now, so let's, so here, the.
01:22
Battery has a say both batteries have the same e -map that's why we will be will denote it as u0 and now we can calculate yeah let's determine the current which path is through a and b so these two lamps are connected in cv sorry in parallel and so the overall the total current which path is through the left equals to u0 divide by r total, which is 5 -6 of u0 over r -0.
02:23
And so the current pathings through the lamp a can be calculated as following.
02:41
So that equals to u0.
02:48
Actually that equals to total current times, yeah, basically, so first of all, let's write down total current pathing in the left as a function of the sum of two currents.
03:10
So that equals to i1, or actually that equals to ia plus ib because.
03:21
So these lamps are connected in theory to another lamps, and that's why current passing through b equals to the current passing through another lamp, which is connected in siri to b.
03:33
So, and ia then equals to u0 divided by 2r and ib, 2r0, equals to u0 divided by 3r0.
04:04
So let's check if our calculation is correct, so let's calculate sum of ia and ib and ib.
04:11
That equals to 2 u0 plus 3 u0 over 6 are 0...