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I encountered a paradox.

When I solve this system using matrix form of electric potentials between circuit knots( i think its called that) I get that the current in R4 is ~86 mA. Using simulations in National Instruments, I got that the current is indeed ~86 mA.

How I did this? Well, I unhooked the branch where R4 is and then calculated what is R Thevenin is 19,9 Ohms. Using further this method, I found that the potential difference between those 2 knots where R is hooked is 5,2 V which in deed is the case.

Inorton=0,26 A. After that calculation of current through resistor R4 is trivial.(86 mA)

But when I use 'classsic' way of solving this circuit and finding Inorton, I get weird results.

When finding R thevenin(for the circut) u unhook the R4 right? and then make all voltage sources short circuited.(I transformed those current sources into voltage sources)

Again I get the right result of ~19 Ohms for R Thevenin. But when I calculate Inorton, I short circuit a branch I am looking current in.

https://www.physicsforums.com/attachment.php?attachmentid=36138&d=1307125539

I get this case.

By my thoughts I should delete this branch with source and resistor. But that gives me wrong result. I get that the current in that branch is: ~ 760mA waaay off.

Problem here is only this branch with source and resistor, what do I do when I short circuit branch with resistor R4.

Any thoughts here?

I hope I was clear

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# Norton's theorem big problem

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