What is Ohm's Law?

Ohm's Law identifies the proportional relationship between voltage, current and resistance in electricity:

It takes one volt to push one amp through one ohm.

Because of this relationship, mathematical formulas can be used to calculate a missing quantity. Below are definitions of the basic quantities of electricity (voltage, current and resisitance) and a table of Ohm's Law formulas.

Voltage (V): Measured in Volts, also known as Electromotive Force (EMF). Voltage is the force (provided by an external source such as batteries) that creates the negative to positive attraction that drives electrons through a circuit.

Current (I): Measured in Amps (amperes). Current is the rate at which electrons are flowing in the circuit.

Resistance (R): Measured in Ohms. Resistance is the holding back of electrons, making it difficult for current to flow. Resistance is created by loads such as lights, motors (and of course resistors).