## Glossary

The glossary of terms is based on terms used in the background pages and easy-reading background pages.

Accelerated = speeded up
Aeration = adding air to a liquid
Aggregate = the stones and gravel used to make concrete
Alternating Current = an electric current that regularly reverses its direction
Amp = abbreviation of ampere, A
Ampere = 1 coulomb of charge per second = 6.24×1018 electrons per second, A.
Bar = unit used to measure pressure, 1bar is 1 atmosphere is 1 000 hp
Bedrock = the hard rock underneath surface soil and gravels
Bus = Bus bar. An electrical connection with many attachment points
Circuit breaker = safety device that cuts the supply of electricity
Condenser = device for converting steam to water
Conduction = transfer of electrical energy from one atom to another.
Conduction = transfer of heat energy through a material, from one molecule to another
Conductor = something that will allow electricity to flow through it
Convection = Transfer of heat by circular mixing of liquids and gases
Conventional current = When electricity is described as flowing from positive to negative.
Corona = an area of flickering light around a high voltage, due to ions being formed
Cumecs = A measurement of water volume in 'cubic metres per second'
Current = Flow of electrons through a material. Shown as I (intensity) in equations
Direct Current = an electric current that flows in one direction only.
Dry steam = Steam that contains no water droplets
Electricity = A form of energy and a flow of electrons from one atom to another
Electro-magnetism = Magnetism produced by an electric current.
Electromagnets = Magnets produced by electricity
Electrons = Negative charge in an atom, that orbits the nucleus.
Energy = the ability to do work and measured in Joules
Faraday = Michael Faraday, one of the greatest electrical experimenters in Science
Faraday's law = A wire in a changing magnetic field will have a current induced in it.
Feedback = When part of the output is returned to the input, to limit it
Flashed Steam = steam made by lowering the pressure
Flashovers = Electricity jumping between surfaces
Flux = the flow of energy, usually measured in Watts per square meter
Frequency = How often something happens each second e.g. 50 Hz
Generator = A machine that converts kinetic energy into electrical energy.
Governor = A control that maintains a steady speed of a machine
Harmonics = Objects vibrate at one frequency but often have multiples of it
Heat = A form of energy caused by the movement/vibration of molecules
Hertz, Hz = Unit used to measure the frequency
Hydro power = Electricity generated using moving water
Hydro-electric = Electricity generated using moving water
Impedance = How hard it is for AC electricity to flow through something.
Induction = Generating electricity in a wire, by a changing magnetic field
Industrial revolution = A period when new machines replaced manual work.
Insulator = Material that does not allow electricity to pass through it
Ionised = Atoms that have electrons added or removed to create Ions
Joule = One watt-second = the energy released in one second by a current of 1 A
Laminations = made up of many thin strips
Latent heat = heat absorbed or given off during a change in state
Lenz = Heinrich Lenz, Estonian scientist who discovered Lenz's Law
Lenz's Law = an induced current will try to minimise the effect that caused it.
Magnetic field = the pattern of magnetism in the space around a magnet
Magnetic flux = the flow of energy, usually measured in Weber per square meter
Magnetic poles = the ends of a magnet where the magnetic force is greatest
Megawatt = 1 million Watts
National Grid = network of wires used to distribute electricity throughout NZ
Ohms = unit used to measure resistance. Larger number means greater difficulty.
Ozone = Molecule made up of three Oxygen atoms.
Physics = The science of light, heat, radiation, electricity, magnetism, atomic structure
Poles = The ends of a magnet where the magnetic force is greatest
Power = A unit of power; power being the rate at which energy is used to do work = rate at which work is done, 1 W =1 J per second
Pressure = force in Newton’s on an area
Radiation = energy that is transmitted in the form of waves
Resistance = how hard it is for electricity to flow through something. Unit is Ohms.
Rpm = Abbreviation for revolutions per minute
Sediment = Small rocks and particles carried and deposited by rivers
Sine wave = A perfectly smooth and uniform wave
Specific heat = Specific heat capacity
Stator = part of a generator, made of electrical windings that do not move
Steam = water in its gaseous state
Switch-yard = A space where high voltage switching of electricity occurs.
Tailings = Piles of river gravels and left after gold dredging and mining
Temperature = How heat is measured
Thermal plants = Power Stations using heat to generate electricity
Turbine = Machine that is made to spin by moving water or gases
Volt = international unit for measuring voltage, V
Voltage = amount of energy per unit charge
Watt = The unit of power = to 1 joule per second, W
Weber = A unit that describes a number of magnetic lines of force and the strength of magnetism
Windings = repeated coils or turns of wire.