00:02
Okay, rvip chart for this circuit.
00:07
Let's draw this circuit.
00:10
So, a battery and goes into two parallel resistors and they come into a third resistor.
00:21
So this one's here.
00:24
So this is r1, this is r2, this is r3.
00:32
And the voltage of the battery is 12 volts.
00:37
Okay, so r, v, i, right? and then r1, r2, r3.
00:53
And do i have to do the, no, that's it, okay.
00:56
So r1 is 10 oms, r2 is 3 oms, r3 is 2.
01:07
Seven ooms so we're gonna fill out the rest of this table okay so if you follow the process doing circuit problems like this isn't isn't really terribly complicated it's really easy if you if you follow the process right it's pretty easy so the first thing you got to do first thing we're going to find is the equivalent resistance so these are the parallel r1 and r2 are parallel so i'm going to add r1 and r2 and to do that they're parallel so i add the reciprocals, right? so it's going to be 10 to the minus 1 plus 3 to the minus 1.
01:43
I'm going to take the reciprocal of that.
01:46
So if i do that, 10 to the minus 1 plus 3 to the minus 1, and then take the, oops, take the reciprocal of that answer, i get 2 .30.
02:02
And i see what they're doing is 2 .7 now.
02:04
So that's 2 .30.
02:07
And now r1 and r2 are in series with r3.
02:11
So i'll add the combination i got there plus r3.
02:17
So this is 2 .3 and r3 is 2 .7.
02:22
And that gives me a total of 5 oms, right? so my rq, my equivalent resistance is 5 oms.
02:31
Okay, so that means the whole circuit has 5 oms.
02:34
Now, once i know this, my second step is find your i total.
02:42
Or the current coming out of the battery, right? how much current comes here? that's i total, the total current through the battery, or through the circuit, i should say.
02:51
Through the battery, same thing.
02:53
And to do this, right, you just use olmslaw.
02:56
So i can say i is v over r, right? so that's 12 over the total resistance of the circuit, which is 5.
03:05
And if you do 12 divided by 5, it's 2 .4, 2 .4 amps.
03:12
Right so i total is 2 .4 amps now that i know this i can go through and you can use kirkoff's laws to figure out the rest right so the loop rule and the junction rule right loop rule or junction rule so first i'm going to say this current here i'll do current in blue right the current that comes here that's 2 .4 amps that's got to be the same current coming here, 2 .4 amps, which means that's got to be the same current that went through r3, right? r3 has to get 2 .4 amps because that's the total that comes out here back into the battery.
03:57
So r3 has to have a current of 2 .4 amps.
04:03
And as soon as here, right, this is the owns law stuff.
04:06
As soon as you know two of these three, you're done.
04:08
You can solve for the third one.
04:10
So v equals i are, right? so i can just multiply.
04:15
2 .4 times 2 .7 and you get 6 .48 and that's the voltage across r3.
04:29
So this one will be voltage in green...