need help calculating current

Discussion in 'Homework Help' started by darkknight, Oct 7, 2009.

1. darkknight Thread Starter Active Member

Oct 7, 2009
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0
I am starting to learn and i am having some problems with this exercise, i was wondering if someone could help me out the resistor of 4ohms is reall throwing me off

by the current law i know the current leaving is the same entering It = I1+I2

It=9A
but at i1 i am getting 12a and i2 getting 6a

Last edited: Oct 7, 2009
2. crashcash New Member

Oct 7, 2009
1
0
let's recalculate the value of Rt. the two 3 ohm resistors at the far right are in series. they add to 6 ohms. that value is in parallel with the 3 ohm in the middle. calculating that will give you 2 ohms. that 2 ohm resistor is in series with the 4 ohm resistor and will give you an Rt of 6 ohms. therefore It is 6 amps. (ohm's law) next the 4 ohm resistor has that same 6 amps current flowing through it. therefore it's voltage must be 24 volts. the remaining 12 volts (36-24) is across the 3 ohm resistor in the middle. therefore it gets 4 amps. because i1 is 4 amps and itotal is 6 amps, the difference of those 2 currents is 2 amps. that flows through the two 3 ohm resistors in series.

hope that helps

crashcash

PS it's always a good idea to label all the components in the circuit.

3. darkknight Thread Starter Active Member

Oct 7, 2009
41
0
but adding all the voltages doesnt that have to be equal to 0 by KVL?? tahnks for you response, sorry if the question is stupid i am just trying to learn

4. Jony130 AAC Fanatic!

Feb 17, 2009
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Last edited: Oct 7, 2009
5. darkknight Thread Starter Active Member

Oct 7, 2009
41
0
thanks for your help, i understand it better now