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Adding up resistors 
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#1
Feb1010, 03:25 PM

P: 361

1. The problem statement, all variables and given/known data
i'm a noob, and i am having trouble adding resistors. this circuit can be reduced to 1 resistor. what is its value? 2. Relevant equations parallel: 1/Rtot=1/R1+1/R2+1/R3+1/R4 series: Rtot=R1+R2+R3+R4 3. The attempt at a solution so i thought 3, 2, 2 added up in series and you just do 6/8+1/4, but this isn't right. =/ i'm having trouble discerning which resistors are parallel and which are in series. any help would be appreciated. 


#2
Feb1010, 04:36 PM

P: 1,408

2 resistors R1 and R2 are in series if one connector of R1 is connected to a connector of R2 and nothing else is connected to these connectors. (or if you can determine that no current can flow through such a connection)
None of the resistors here is in series with any other. The 3 ohm resistance isn't in series with any of the 2 ohm resistances because the point between the 3 ohm resistance and any of the 2 ohm resistances is also connected to the other 2 ohm resistance 2 resistors are parallels if one connector of R1 is connected to a connector of R2 and the other connector of R1 is connected to the other connector of R2. There's only 1 pair of resistances here thats parallel. The direction they are drawn in doesn't matter. Once you combined those resistances, you can look again for a pair of resistances that is in series or parallel. 


#3
Feb1010, 05:03 PM

P: 361

huh? so are you saying i can disregard the 3 Ohm resistor?
i know the answer is supposed to be 2. i don't know how to get there though. 


#4
Feb1010, 05:10 PM

P: 1,408

Adding up resistors



#5
Feb1010, 05:21 PM

P: 361

is 3 parallel with 4 and 2 is parallel with 2?



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