What is the Ohm's law formula?

• A. I = V x R
• B. V = I x R
• C. R = V / I
• D. P = I x R

Answer: (B)

Voltage, current, and resistance are linked by Ohm's law. The most straightforward way to express it is that voltage equals the product of current and resistance: V = I × R. This form directly shows how a given current through a resistor creates a voltage drop across it, with units that line up: volts come from amperes times ohms.

You can rearrange this relationship to solve for other quantities, such as current (I = V / R) or resistance (R = V / I), and those forms are mathematically equivalent. The option that would incorrectly describe current as a product of voltage and resistance is not valid, and the expression for power is different (P = VI, or P = I^2R, or P = V^2/R), not I × R.