# Help with this circuit

Discussion in 'General Electronics Chat' started by Pro.Z, Oct 24, 2009.

1. ### Pro.Z Thread Starter New Member

Oct 24, 2009
1
0
Hello guys,

My doctor gave us a quiz but I could not solve it

I drew the circuit to try to solve but I was confused how to determine whether the resistors are in parallel or in series

And , could you please give me some difficult circuits so that I can practice and they should have only resistors and voltage sources or current sources

thanks ,
sorry for my bad drawing

2. ### hgmjr Moderator

Jan 28, 2005
9,030
215
You could start by noting that the two 12 ohm resistors are in parallel so they can be replaced by a single 6 ohm resistor.

hgmjr

3. ### Accipiter New Member

Sep 20, 2009
9
0
Do you know how to use Thevenin's theorem? If so, then you can apply it several times to this circuit in order to simplify things a bit.

First, do like hgmjr said, and combine those two 12Ω resistors (Do you see why they are in parallel?). Then, you can combine it with the 4Ω resistor in series. Then, form the Thevenin equivalent circuit of the voltage source, 7Ω resistor, and your newly combined resistor. Just continue in like manner from there...

4. ### Duane P Wetick Senior Member

Apr 23, 2009
408
18
It helps to redraw the circuit slightly, starting with the 2-12 ohm resistors in parallel, then solve the parallel networks, going from right to left.

5. ### RiJoRI Well-Known Member

Aug 15, 2007
536
26
I was confused how to determine whether the resistors are in parallel or in series

Call one end of a resistor "A", and the other "B". If both "A" ends of the resistors are connected, and both "B" ends of the resistor are connected, they are connected in parallel. If only one end (A-A, A-B, B-B, or B-A) are connected, they are in series.

Note that while you are not getting a detailed solution, you ARE getting detailed help. (We won't be looking over your shoulder the next time you get a quiz! :~) )

--Rich

6. ### maxpower097 Well-Known Member

Feb 20, 2009
795
388
Just read a great book that had a chapter on this. Check out "Electrical Engineering 101" 2nd Edition by Newnes books. It really is a great book. It basically follows the AAC's book but goes a little deeper. I don't think I can legally post the chapter so you'll have to get the book. Its well worth it though.