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key terms and formulae for the electricity topic


Positively charged particle, found inside the nucleus of an atom


Negatively charged particle; located outside the atomic nucleus


Neutral particle, found in the nucleus of an atom


a charged atom, either positive or negative

staticly charged object

when an object has gained/lost electrons and has an overall unbalance of charge

static discharge

when charge flows to Earth, often as a spark

Earthed object

An object in contact with the ground via a conductor so no charge build up is possible


The rate of flow of electrons


The unit of current

Voltage or potential difference

The energy given to the current


The unit of voltage/potential difference


The opposition to the flow of current


The unit of resistance

Resistance formula (Ohm's Law)

Resistance = Voltage / Current


An material with 'free' electrons that charge can flow through easily


A material that charge cannot easily flow through

Current formula

Current = charge / time

Voltage formula

Voltage = Energy transferred / charge


the unit of charge

The current in a series circuit

the same at all points

the voltage in a series circuit

shared between the components

total resistance in a series circuit

the sum of the individual resistances

the current in a parallel circuit

splits at a junction but the total current is constant

the current at a junction

takes the path of least resistance

the voltage in a parallel circuit

each branch gets the full voltage from the cell

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