How is Ohm's Law applied in automotive electrical systems?

• A. V = R / I
• B. I = V × R
• C. V = I × R; analyzing voltage, current, and resistance helps diagnose circuits and determine whether components are functioning.
• D. V = I + R

Answer: (C)

Ohm's Law in automotive electrical systems is the relationship between voltage, current, and resistance, captured by V = I × R. This lets technicians diagnose circuits by linking how much current should flow with the voltage available and the resistance the circuit presents. In practice, knowing any two variables lets you find the third, helping locate faulty wiring, corroded connections, or failing components. For example, if you know the supply voltage and measure the current, you can infer circuit resistance; or if a component’s resistance is known, you can predict the current at a given voltage. The other forms don’t fit the relationship: V = R / I mixes units, I = V × R would misstate how current depends on voltage and resistance, and V = I + R adds unlike quantities. The correct form, V = I × R, underpins analyzing voltage drops and component function in automotive circuits.