Which equation is Ohm's Law expressed as V = I × R?

• A. V = I × R
• B. P = V × I
• C. I = V × R
• D. R = I × V

Answer: (A)

Voltage across a conductor is determined by how much current is flowing and how much resistance the path offers. Ohm's law in its common form says V = I × R, meaning the voltage equals the current times the resistance. This shows a direct, proportional relationship: for a given resistance, increasing the current raises the voltage in a linear way, and for a given current, increasing the resistance raises the required voltage.

The units line up as well: amperes times ohms gives volts, so the equation is dimensionally consistent. You can rearrange it to I = V / R or R = V / I if you need to solve for those quantities. A related, but separate, relationship is P = V × I, which describes electrical power.

Example: if the current is 2 A and the resistance is 5 Ω, the voltage is V = I × R = 2 × 5 = 10 V.