Final answer:
To calculate the overall resistance of the car's headlamp circuit with a 12 V battery and a 15 A current, use Ohm's law (V = IR) to get the resistance as 0.8 ohms.
Step-by-step explanation:
The question involves calculating the overall resistance of a car's headlamp circuit. To find the resistance, you can use Ohm's law, which states the relationship between voltage (V), current (I), and resistance (R) as V = IR. Given that a current of 15 A passes through the car's headlamps and the car's battery is 12 V, you can rearrange Ohm's law to solve for resistance.
R = V / I
Plugging in the values, we get:
R = 12 V / 15 A = 0.8 Ω
So, the overall resistance of the headlamp circuit is 0.8 ohms.