Ohm's Law Definition

In physics, Ohm's law is defined as the electric current passing between the two points of a conductor directly proportional to the Voltage between them. In other words, it is a relation among Voltage (V), Resistance (R), and current (I). Whereas, Voltage is defined as the potential difference between two points. Current is an electrical charge passing through a conductor, and Resistance is the force that opposes the flow of an electric current. Ohm's law is named after the German physicist Georg Simon Ohm, the first to verify Ohm's law experimentally.


Table of Contents

Formula of Ohm's Law

To instantly determine Ohm's law, you can use the formula listed below:

V = I * R


V = Voltage of a circuit (represented as volts "v")

I = Current of a circuit (represented as ampere "A")

R = Resistance in a circuit (represented as ohm "Ω")


If you want to calculate Ohm's law, you can use our Ohm's Law Calculator.


For a more precise and clear understanding of the concept, let us solve an example below:

Suppose a resistor of 4 Ω is connected in your circuit with a current of 30 amperes across its terminals. Then find out the voltage passing through the circuit.

Given data

Current = I = 30 amperes
Resistance = R = 4 Ω

To Find

Voltage = ?


To find out the voltage passing through the circuit, we will use the formula listed below:

Resistance = R = 4 Ω

Putting values in the formula:

V = 30 * 4 = 120 volts