Question

an automobile battery when connected to a car radio provides 12.5V to the radio.when connected to a set of headlights it provides 11.7V to the headlights .Assume the radio can be modeled as 6.25 ohm resistor and the head lights can be modeled as 0.65 ohm resistor .what are thevenin and Norton equivalents for battery

Answer 1

Regard the battery as an EMF voltage E, and a series resistance R. You need to find both of these. Current in radio = 12.5 volts / 6.25 ohms = Current in headlights = 11.7 volts / 0.65 ohms = Now you can work out the equations for E and R: Work out the value of the internal resistance in terms of the voltage across it and the current in it: (E - 12.5 )/ radio current = R (E - 11.7) / headlight current = R Solve for E and R.