A car's starter motor draws 150 A while the battery holds 11.0 V across it. What is the motor's effective resistance?

1. Rearranging Ohm's law I = V/R gives R = V/I. 2. Substitute: R = 11.0 V / 150 A. 3. Divide: R = 0.073 ohm. 4. A starter has to pass a very large current from a small voltage, so its resistance must be tiny. 5. 13.6 ohm is the trap of dividing current by voltage upside down and misplacing the decimal; it would allow less than one ampere to flow. _Source: OpenStax College Physics (CC BY 4.0), Ch 20 "Electric Current, Resistance, and Ohm's Law", section 20.2 Ohm's Law: Resistance and Simple Circuits_