Electricity Terms

Ohm's Law

It states that voltage is equal to the current multiplied by the resistance. This is known as Ohm's Law. V = IR. In an electrical system, power (P) is equal to the voltage multiplied by the current. P = VI

Current (I)

Measure of amount of electrons going through a circuit. Current is measured in amperes, or amps (A). Computer power supplies deliver different amperages for each output voltage.

Voltage (V)

Measure of force required to push electrons through circuit. Computer supply usually produces several different voltages.

Resistance (R)

Opposition to the flow of current in a circuit. Resistance is measured in ohms. Lower resistance allows more current, therefore more power, to flow through a circuit. A good fuse will have low resistance or a measurement of almost 0 ohms.

Power (P)

Voltage x Current. Power is a measure of the force required to push electrons through a circuit, called voltage, multiplied by the number of electrons going through that circuit, called current. The measurement is called watts (W). Computer power supplies are rated in watts.