Why Does the Maximum Power Transfer Theorem Yield a Negative Resistance?

[prashantgolu]

i was solving one question...it said find out value of r in a circuit so that the 6 ohm resistor consumes maximum power...i applied max power theorem ...and calculated the thevenin eqivalent resistance accrss 6 ohm resistance...and put it equal to 6...but the r cam eout to be negative...so wat to conclude from this...

 

[MATLABdude]

It would help if you posted a diagram of the circuit in question. If this is an ideal source in series with a source resistance and the 6 ohm resistor, then this question is best answered by thinking about the following question:

What is the max power transfer theorem?

I suspect a Mod will be by shortly to move this question, but homework questions like these should be posed in the Homework section:
https://www.physicsforums.com/forumdisplay.php?f=152

 

[prashantgolu]

yes...its just an ideal source...some resistances and a 6 ohm resistance...i just removed it and found out thevenin equivalent across its terminals...and compared it to be 6 for max theorem..i am attaching a file

 

[MATLABdude]

As you surmise, max power transfer happens when the load resistance is equal to the source resistance. Have you determined the Thevenin equivalent of the circuit connected to the 6 ohm resistor (i.e. everything to the left of that resistor)?