Which equation represents Ohm's law for current?

• A. I = V / R
• B. V = IR
• C. R = V / I
• D. I = VR

Answer: (A)

Ohm's law shows how current, voltage, and resistance relate in a circuit. To find the current, you divide the voltage by the resistance: I = V / R. This means the flow of charge (current) is determined by the voltage driving it and the resistance it faces. The other forms are just different ways to express the same relationship for other quantities: V = IR expresses voltage in terms of current and resistance, R = V / I gives resistance in terms of voltage and current, and I = VR would not be correct because multiplying voltage by resistance does not yield current in general. The unit check supports the correct form: volts divided by ohms equals amperes, so I = V / R is the proper equation for current.