# Complex circuits lab

1. Mar 11, 2014

### Sneakatone

1. The problem statement, all variables and given/known data
uploaded is the circuit with resistors technically in series.
R1 had a measured value of 160 ohms (from A to B) 0.0617 Amps
R2 had a measured value of 387 ohms (from B to C) 0.025 amps
from A to C the resistance measured is 243.9 ohms 0.041 amps

this means that there is a parallel resistance some where in between but I do not know how to solve to find which is which.

2. Relevant equations
for series R1+R2...=Rtotal
for parallel (R1*R2)/R1+R2

I=V/R

3. The attempt at a solution
I tried 243.9=162+(R3R4)/R3+R4 assuming one of the resistors are not parallel.

#### Attached Files:

• ###### Untitled.png
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Last edited: Mar 11, 2014
2. Mar 11, 2014

### BvU

For the former: Fill in something under 3.
For the latter: proofread. What is posted now is very incomplete.

3. Mar 11, 2014

### Sneakatone

sorry I for got my photo , I added what I tried but Im still lost.

4. Mar 11, 2014

### BvU

Well, you tried. I must admit that this doesn't help me understand what it's all about.
Are all these currents (0.0617, 0.025, 0.041 A) measured at the same time?
I understand A is not Argentina, B is not Belgium and C is not Cambodia, but they might as well be, because you don't mention anything about them...
And R3 and R4 are probably not parachuted in, but for me they appear out of the blue.

My telepathic capabilities are virtually zero. Most other potential helpers have the same "problem". Try to help us help you ! Proofread critically !

5. Mar 11, 2014

### Sneakatone

sorry for not being clear in the picture A,B,C are just node indicators for the resistors.
0.0617, 0.025, 0.041 Are the amp measurements in the specified resistor .

6. Mar 12, 2014

### mr_pavlo

And how about the current directions (A->B or so ...) because if all currents have the same directions then there must be a mistake in measurements because the current between A and C is smaller than current through R1. If there is any parallel resirtance to R1 or R2 the overal current would be higher. And isn't it posible to measure voltages between all nodes. It would tell us much more about any parallel conections.

7. Mar 12, 2014

### BvU

Just fishing: You were given a mystery box with three sockets for banana plugs or something. They tell you that inside are some resistors, nothing else. You connect a voltage of some 10 V and measure voltage and current. From A-B, B-C and finally from A-C.

Assignment: what is in there, how is it connected, what are the values of the individual resistances ?

Is this a rendering of what this is all about? If so, perhaps you should have helped us a bit more than you actually did.

Is this completely wrong? In that case put us right by giving us a complete, unambiguous story.
(from what I dreamed up you can see what some (not at all stupid) people imagine from a relatively simple description!)

Can you reassure Pavlo and me in this respect ?

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