# What is Ohm's law?

- Author:
- Allen Olson

In physics, one area of study is electric circuits, and Ohm's law relates three key concepts of electric circuits: voltage, current, and resistance. These quantities have standard units of measurement and standard abbreviations when used in formulas:

- Voltage (
*V*) is measured in volts (V). - Current (
*I*) is measured in amps (A). - Resistance (R) is measured in ohms (
).

*V*=*IR*. In words, the voltage is quantitatively equal to the product of the current times the resistance. This relationship holds true for fairly large ranges of voltage, current, and resistance.