Headlights on a car dim when the starter motor is operated due to the significant current draw from the starter motor, which is 100 A. This high current causes a voltage drop across the internal resistance of the battery, which is 0.040 ohm, leading to a decrease in the effective voltage available to the headlights. The battery's electromotive force (emf) remains at 12V, but the voltage supplied to the headlights drops as the starter motor engages.
PREREQUISITESAutomotive engineers, electrical engineers, physics students, and anyone interested in understanding automotive electrical systems and their behavior during high current draw situations.