Physics
Basic

Ohm's Law

Voltage equals current times resistance.

Formula

V=IRV = IR

Variables

VVoltage (V)
ICurrent (A)
RResistance (Ω)

Example

A 12 V battery across a 4 Ω resistor drives I = 12/4 = 3 A.

Did You Know?

Georg Ohm was initially ridiculed for his law; today it's the first equation every electronics student learns.