Which of the following represents Ohm's Law?

• A. Current equals resistance times voltage
• B. Power equals voltage times current
• C. Voltage equals current times resistance (V = IR)
• D. Resistance equals voltage divided by current

Answer: (C)

Ohm's Law describes how voltage, current, and resistance relate in an electrical conductor. The standard, direct form is voltage equals current times resistance. This shows that the voltage across a component drives the current through it in proportion to the resistance. If you know the current and the resistance, you can find the voltage; if you know voltage and resistance, you can find the current. Units line up cleanly: volts come from amperes times ohms.

The other ideas mix in a different concept or misstate the relationship. For example, current equals resistance times voltage would imply the wrong dependence and doesn’t match how current behaves in circuits. Power is described by P = VI, which is a separate relation. You can rearrange the law to get R = V / I, but the most direct and commonly used form is V = IR.