Electric power source with internal resistance · CAP 2006 #Problem 2
Physics · electromagnetism
Problem
A source of electric power with electromotive force E and internal resistance r, is connected to a resistor.
1) Find the power delivered to the resistor as a function of the resistance of the resistor.
2) Find the power produced by the source as a function of the resistance of the resistor.
3) Sketch graphs of these two functions.
4) Treating the efficiency of the source as the ratio of power consumed to power produced by the source, find the efficiency of the source of electric power as a function of the resistance of the resistor and sketch the graph of this function.
5) Find the resistance of the resistor that corresponds to the maximum power delivered to the resistor, and calculate the efficiency for this resistance.