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Topic: Circuitry (Resistors)  (Read 6333 times)

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Offline nj_bartel

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Circuitry (Resistors)
« on: January 28, 2009, 08:54:50 PM »
Given a circuit like this

          |--10ohms--25V=>--|
|------|--10ohms----------|-----------|
|         |--10ohms----------|              |
5ohms                                           12ohms
|                                                     |
|--------------------------------------|


How would I solve for current through the 12ohm resistor?  I thought if I found the equivalent resistance of the entire system then used ohm's law I'd get it, but no luck.

Thanks!

Offline ARGOS++

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Re: Circuitry (Resistors)
« Reply #1 on: January 29, 2009, 05:17:08 AM »

Offline nj_bartel

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Re: Circuitry (Resistors)
« Reply #2 on: January 29, 2009, 01:32:03 PM »
Got it, thanks  :)

Offline ARGOS++

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Re: Circuitry (Resistors)
« Reply #3 on: January 29, 2009, 01:36:56 PM »

Offline ARGOS++

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Re: Circuitry (Resistors)
« Reply #4 on: May 03, 2009, 04:50:22 PM »
                             Copy of the lost replay No. 1

Dear nj_bartel;

As a first step your suggestion is ok, but it is an old trick to present the circuit this way to confuse students.

But there is an easy recipe to solve such problems, but in your case first a few preparation are required.

Preparation:
   a.)   Replace your source by only its connection-points and name them S1 and S2.
   b.)   Rename the 10 ohm resistors from the top with 10A, 10B, and 10C.
   c.)   Name the connection between  5 Ohms and 10A, 10B, 10C with A.
   d.)   Name the connection between 12 Ohms and  10A and 10B  with B.

General Recipe:
     Redraw/Stretch the circuit this way that S1 and S2 becomes the most left and most right place on your paper, and point A and B lie in-between.
(For your example:       S1   -       A     -     B     -     S2.)   

I’m pretty sure that now it will be much easier solvable.

I hope to have been of help for you to start.
Good Luck!
                    ARGOS++


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