power versus resistance

Thread Starter


Joined Feb 9, 2007
i need some help with graph of power versus load of resistance when there is a source of emf with internal resistance. maximum and min power?? how to do this??


Joined Nov 17, 2003
Further to Papabravo's answer, you need to compute the power values for each value of resistance you have. For this you need to assume constant current and voltage to get the plot for Power Vs Resistance.

So for P = (I^2)*R

I = some constant value

And you can calculate P for different values of R. Plot resistance on the x-axis and power on the y-axis.



Joined Apr 2, 2007
when there is a emf source with internal source try making a eq circuit and
place internal resistance in series with emf source use thevenin's theorem
to get simplified circuit in case of complex circuits, it really isnt that hard,
one important clue for max power the load impedance must equal the circuit's
thevenin's eq ckt impedance.