Ohm’s Law

Ohm’s Law is a mathematical equation that shows the relationship between electric voltage, current and resistance. Ohm’s Law was named after Bavarian mathematician and physicist Georg Ohm.

Ohm’s Law can be stated as three mathematical equations, all derived from the same principle. In the following equations, V is voltage measured in volts, I is current measured in amperes and R is resistance measured in ohms:

  • V = I x R
  • R = V / I
  • I = V / R

Knowing any two of the values of a circuit, one can determine the third using Ohm’s Law. For example, if a circuit has a current of 2 amperes, and a resistance of 1 ohm, then according to Ohms Law, voltage equals 2 (V = 2 x 1).

Typically, Ohm’s Law is only applied to DC circuits and not AC circuits.

Note well: The letter “E” is sometimes used in representations of Ohm’s Law for voltage instead of “V.”

Webopedia Staff
Since 1995, more than 100 tech experts and researchers have kept Webopedia’s definitions, articles, and study guides up to date. For more information on current editorial staff, please visit our About page.

Top Articles

The Complete List of 1500+ Common Text Abbreviations & Acronyms

Text Abbreviations reviewed by Web Webster   From A3 to ZZZ we list 1,559 SMS, online chat, and text abbreviations to help you translate and understand...

Windows Operating System History & Versions

The Windows operating system (Windows OS) refers to a family of operating systems developed by Microsoft Corporation. We look at the history of Windows...

How to Create a Website Shortcut on Your Desktop

Website Shortcut on Your Desktop reviewed by Web Webster   This Webopedia guide will show you how to create a website shortcut on your desktop using...

Generations of Computers (1st to 5th)

Reviewed by Web Webster Learn about each of the 5 generations of computers and major technology developments that have led to the computing devices that...

Pipeline

A pipeline is a figurative measurement of client or customer progress through a...

Direct Marketing

Direct marketing is a strategy for selling products and services directly...

Compact Disc

A compact disc (CD) is a polycarbonate disc measuring 120 mm in diameter...