P3.2 Simple circuits

potential difference

the difference in electrical charge between two points in a circuit expressed in volts

Volts

unit for voltage

Voltmeter

A device used to measure voltage, or potential difference

Electrical working

Energy transfer by an electric current

Energy transferred (J) =

potential difference (V) x charge (C)

series circuit

An electric circuit with only one path through which charge can flow

Ammeter

a device used to measure current

parallel circuit

A circuit that contains more than one path for current flow.

Resistance

A material's opposition to the flow of electric current.

Ohms

unit for resistance

potential difference =

current x resistance

Variable resistor

A resistor whose resistance can be changed.

Characteristic graph

A graph of current against potential difference.

Linear circuit unit

The resistance does not change as the potential difference changes

Non-linear circuit element

a circuit component which has a resistance that does change

Ohm's Law

the current in a circuit equals the voltage difference divided by the resistance