Understanding how to re-draw circuits

Lopez · Dec 14, 2014

1. The problem statement, all variables and given/known data

I need to find I1,I2,I3,Va,Vb but i dont even know to read the circuit. i know how to to do series circuits and parallel circuits but not this. How do i read this circuit and know which ones are in parallel or in series. is there a way to re-draw it? I have the solution and answer. Therefore i dont need the step by step solution since i already have it,is just that it doesnt explain why they did it that why.
These are the I1=4A ,I2=1.33, I3=.67, I4=2.67,va=8.0,and vb i dont know.
Please help understanding what is going on in this circuit.

Stephen Tashi · Dec 14, 2014

If you need a loop, put in a 20 V battery with the positive plate connected to E. Connect the negative plate of the battery to the 3 grounds at the bottom of the diagram.

Mark44 · Dec 14, 2014

I would work my way up from the bottom, simplifying bits and pieces as I go. R₅ and R₃ are in parallel, right? So you could combine those two resistors into a single resistance. Keep chipping away at it until you have a single loop.

donpacino · Dec 15, 2014

If you combine circuit elements you will lose that components individual voltage and/or current.

I reccoend doing a KCL at Va and Va. Then solve for Va and Vb, and the currents will be easy to find.

Lopez · Dec 15, 2014

thanks for the tip

Lopez · Dec 15, 2014

Mark44 said: ↑

I would work my way up from the bottom, simplifying bits and pieces as I go. R₅ and R₃ are in parallel, right? So you could combine those two resistors into a single resistance. Keep chipping away at it until you have a single loop.

if i do ((R5||R3)+R2)||R4 and this would be in series with R1 right? now to get Vb i think i would do Vb=R5(I2-I3) but what if that R5 was not there then how would i solve for vb

donpacino · Dec 15, 2014

Lopez said: ↑

if i do ((R5||R3)+R2)||R4 and this would be in series with R1 right? now to get Vb i think i would do Vb=R5(I2-I3) but what if that R5 was not there then how would i solve for vb

If R5 was not there then I2 and I3 would change. you cannot solve for an unknown value with unknown values

Log in or Sign up

Understanding how to re-draw circuits

Lopez

Stephen Tashi

Mark44

Staff: Mentor

donpacino

Lopez

Lopez

donpacino

Logic circuits drawing program (Replies: 3)

Help with drawing a circuit diagram (Replies: 1)

Drawing circuits. (Replies: 6)

Draw the eqivalent circuit. (Replies: 9)

Drawing circuits (Replies: 1)