# Homework Help: Maximum Electric power

1. Dec 10, 2011

### omni

i asked to find What should be connected instead of R6 to get the Maximum Electric power.

so what i think i need to do first is to find RTh (R-Thévenin).

so in the picture you can see the same Electric circuit (NO1 is the original Electric circuit,and NO2 is what i started to do to find RTH) but what i should do with the current source? (do i need to cut it?)

i not sure if Thévenin's theorem is the correct way to solve this kind of question.

need some help here.

thanks.

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2. Dec 10, 2011

### Staff: Mentor

You'll 'cut' the current source when you proceed to find the Thevenin resistance. But to find the Thevenin voltage it's necessary to have it active!

Note that with R6 removed from the circuit that the path for the current from the current supply is restricted to flow, without splitting, to nodes D and C. That fixes their node voltages. If you know the voltage at node C then you should be able to find the voltage at node B. With all the node voltages in hand you should find VAB with no trouble!

3. Dec 11, 2011

### omni

if i found the voltage at node D C B in circuit NO1 is will not stay the same at circuit NO2 right?

and for the current is flow like this (i mark it in blue line).

thanks.

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4. Dec 11, 2011

### Staff: Mentor

Right. Your circuit NO2 has only the current source active. I'm not sure what the purpose of circuit NO2 is. In order to find the Thevenin voltage for the circuit you will need to have the contributions from all the sources. Are you applying superposition?
You know the current flow coming from the current source (2 amps). So, with the load resistor R6 removed, what is the voltage at node D? At node C? At node B? You should be able to calculate their numeric values.

5. Dec 23, 2011

### omni

hi thanks :) i solve it.