
Homework Help Stuck on a textbook question or coursework? Cramming for a test and need help understanding something? Post your questions and attempts here and let others help. 

Thread Tools  Display Modes 
#1




In a SeriesParallel circuit, how do you find the resistance and the current if only the voltage is given? 5 resistors in series and 1 resistor in parallel.
R1= 3 ohm Voltage= 3V Current 1A R2= 5 ohm Voltage =1.65 current 0.33A R3= ??? voltage= 4 volts (parellel) R4= 4 ohm Voltage 1.32 Current 0.33 R5= 1 ohm voltage 1 volt current 1A R6=3ohm voltage 0.99 current 0.33 
#2




Quote:
If all these resistors that are in series are really in series then the current through them all will be the same. If R1 and R2 are in series you can't have 1A through one and .33A through the other.
__________________
Eddy Current is a little dizzy over Milli Volt. 
#3




Quote:
Rt=R1+R2+R3 For resistors in parallel Rt=R1*R2/R1+R2 to add more than 2 resistors in parallel do above calc for R1 and R2 Then do same calc for above result and R3 then simply add total series and parallel resistor values together. 
#4




Quote:
All current that goes into a circuit must leave the same circuit. (since you have 3 resistors that have .33a they must be in series.) R2 + R4 + R6 so 5ohms + 4ohms +3ohms = 12ohms Rt1 = 12 It1 = .33amps Et1 = Rt1 X It1 or 12 X .33 = 3.96v (I will round that to 4v)  and two resistors have 1 amp of current flowing they must also be in series. Rt2 = R1 + R5 or 3ohms + 1 ohm = 4ohms so E2t = It2 X Rt2 or 4ohms X 1 amp = 4volts  Since both have a total of 4 volts across the series branches both of these series circuits are in parallel Then add the R3 with a 4volt drop also to the circuit, and since its in parallel, it uses E = I X R or 4V = 1amp X 1ohm, Since the 4volts is across the resistance of R3 it must be 4ohms and a current of 1 amp. ohms law proves this R =E / I or 4v / 1 amp = 4 volts  To continue: you have a series parallel circuit (that is actually three series circuits, that are in parallel  Just for fun: Adding the currents and using ohms law, we see that Rt = Et / It or 4v / 2.33 amps = 1.73 ohms of Total resistance. This is a close approximation of the total resistance of the circuit.  There are other methods that may work also, but, I find this the most logical, without going into higher math, (which I abhor)  Hope this comes close to the answer your looking for. 
Tags 
circuit, seriesparallel 
Related Site Pages  
Section  Title  
Worksheet  Seriesparallel combination AC circuits  
Worksheet  Parallel DC circuits  
Textbook  Seriesparallel R, L, and C : Reactance And Impedance  R, L, And C  
Textbook  Series resistorcapacitor circuits : Reactance And Impedance  Capacitive  
Textbook  Series resistorinductor circuits : Reactance And Impedance  Inductive  
Textbook  Zener diodes : Diodes And Rectifiers  
Textbook  Mesh current method : Dc Network Analysis  
Textbook  Analysis technique : Seriesparallel Combination Circuits  
Textbook  Simple parallel circuits : Series And Parallel Circuits  
Textbook  Simple series circuits : Series And Parallel Circuits 
Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Series and parallel circuits  TM The Fool  General Electronics Chat  4  03072013 09:29 PM 
Charging DC Batteries some in parallel and some in series  scozzari01  General Electronics Chat  1  11242012 01:30 PM 
series & parallel circuit calculations  ngrobertson  Homework Help  3  04142011 01:34 AM 
Mixed Series & Parallel circuit  how to allocate watts ?  DrAlloway  The Projects Forum  11  04132011 08:56 PM 
RC series and parallel config  Thevenin's Planet  Homework Help  7  05012010 05:29 PM 
Thread Tools  
Display Modes  

