6.1.1 Common Electrical Terms

Ampere (A)

A unit of current or rate of flow of electricity equal to volts/ohms (Ohm's law).

Coulomb (C)

Unit of electricity equal to the quantity that passes a cross section of a conductor in one second when the current is one ampere.

Dielectric constant of an insulating material

Ratio of capacitance of a condenser having the material as the dielectric to the capacitance of the same condenser with vacuum as dielectric.

Dielectric strength of an insulating material

Maximum voltage or potential gradient that the material can withstand without rupture.

Farad (F)

Unit of electric capacitance = that capacity whose potential will be raised one volt by the addition of the charge of one coulomb. The practical unit is the microfarad ( F).

Henry (H)

Unit of inductance = inductance of a closed circuit in which an electromotive force of one volt is produced when the electric current traversing the circuit varies uniformly at the rate of one ampere per second.

Hertz (Hz)

The frequency of an alternating current in cycles per second.

Kilowatt (kW)

1000 watts (W).

Kilowatthour (kWh)

1000 watthours (Wh).

Kilovolt-ampere (kVA)

1000 volt-amperes (VA).

Mho

Unit of electric conductance = 1/ohm (reciprocal ohm). Also called siemen (S).

Ohm ( ?)

Unit of electric resistance.

Power factor

The ratio of active power to apparent power.

Specific inductive capacity (SIC)

Dielectric constant = permitivity.

Volt (V)

Unit of electromotive force.

Watt (W)

Volts amperes (dc);