Which equation represents Ohm's Law?

• A. Current = Voltage x Resistance
• B. Voltage = Current x Resistance
• C. Resistance = Voltage x Current
• D. Voltage = Power x Resistance

Answer: (B)

Ohm's Law shows how voltage, current, and resistance relate in a circuit. It states the current through a conductor is proportional to the voltage across it and inversely proportional to its resistance, which leads to the equation V = I × R. This form makes it clear that increasing voltage drives more current through a fixed resistance, and increasing resistance reduces the current for a given voltage. You can also rearrange it to I = V / R or R = V / I to solve for any unknown.

The other forms don’t fit because they mix the quantities in ways that don’t match their units and physical meaning: current equals voltage times resistance would imply amps equal volts times ohms, which isn’t dimensionally correct; resistance equals voltage times current also gives incorrect units; voltage equals power times resistance brings in power, which isn’t part of the basic Ohm’s Law relationship.