Glossary of Electrical Terms

GLOSSARY OF TERMS

The following is a small extract from the new Glossary of Electrical Terms to be introduced in the 2023 edition of the SPARKS Handbook.

A D F

A.C. (ALTERNATING CURRENT)

The flow of an electric current, first in one direction and then in the reverse direction for the type of crimp. Incorrect use can lead to overheating and melting of the crimp

AMMETER

An instrument used for the measurement of electric current

AMPERE

A unit of electrical current

ANODE

A positive electrode

B

BATTERY

A number of electrical storage cells arranged in series or parallel

C

CELL

A device for producing electric current by chemical action

D.C. (DIRECT CURRENT)

The flow of an electric current in one direction only

DELTA

A method of electrical circuit connection used in three – phase supply systems where the load is balanced and does not require a neutral connection

DIAC

A solid-state device that is designed, together with other types of solid state devices to produce a pulsed waveform

E

ELECTRICITY

The general term used to describe the effect of electric charge whether static or in motion

ELECTRIC POWER

The rate of doing work, measured in Watts. Power in watts is the product of potential difference in volts and the current in amperes, so in formula:

P = V x I or P = U x I

ELECTRODE

A) A conductor that can allow electric current to enter or leave a medium such as an electrolyte

B) An element that collects or emits electrons as in a semiconductor device

FLEMING’S LEFT AND RIGHT HAND RULES

Two rules developed by Sir John Fleming. The rules are designed to assist in the understanding of the relationship between motion, e.m.f. and magnetic flux in electric machines

The Hand rules use the first and second fingers and thumb of each hand to represent magnetic flux, electric current and the resulting movement

The Left Hand Rule relates to electric motors and the Right hand Rule to electric generators

FLUX

A) A substance that can be added in order to assist fusion as in gas welding

B) A generic term used to express the ‘rate of flow’ or ‘movement’ of a property such as ‘magnetic flux’, ‘luminous flux’ or ‘electric flux’

FUSE

An overcurrent protective device designed to open circuit in the event of an abnormally large current flowing in an electrical circuit or apparatus. The abnormally large current can be as a result of an electrical fault or overload.