A unit of measure of reactive power. Vars may be considered as either the imaginary part of apparent power, or the power flowing into a reactive load, where voltage and current are specified in volts and amperes.


the internal resistance of a fluid caused by molecular attraction which makes it resist a tendency to flow.


a unit of electrical pressure (or electromotive force) which causes current to flow in a circuit. one volt is the amount of pressure required to cause one ampere of current to flow against one ohm of resistance.


that force which is generated to cause current to flow in an electrical circuit. it is also referred to as electromotive force or electrical potential. voltage is measured in volts.

Voltage (E)

An electromotive force or “pressure” that causes electrons to flow and can be compared to water pressure which causes water to flow in a pipe. Measured in volts.


an instrument for measuring the force in volts of an electrical current. this is the difference of potential (voltage) between different points in an electrical circuit. voltmeters are connected across (parallel to) the points where voltage is to be measured.


a unit of measure for indicating the electrical power applied in a circuit. it is obtained by multiplying the current (in amperes) by the electrical pressure (in volts) which cause it to flow. that is: watts = amperes x volts.