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


please help

 

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.

 

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

 

Hmm,
Vbat=V1+V2

V1=It*4Ω=24V

V2=I1*3Ω=12V=I2*(3Ω+3Ω)

Vbat=24V+12V=36V
And now
36V-24V-12=0V


http://forum.allaboutcircuits.com/showthread.php?t=26675&highlight=KVL&page=2 (post17)

 

thanks for your help, i understand it better now