1.Electricity

Electric current

Electric current

The rate of net flow of any electrically charged particles

Coulomb

Charge that passes when 1 ampere of current flows for 1 second

Potential difference

Energy transfered per unit charge transfered from electrical to other forms

Resistance

Ratio of the p.d. across the component to the current through it

Ohms law

For a metallic conductor the p.d across it is proportional to the current through it, when other physical conditions such as temperature are constant

Superconductor

Material that when below a critical temperature resistance is 0

Critical temperature (Tc)

Temperature where if below a material becomes superconducting

Resistivity

1. The extent to which a material opposes the flow of electric current through it.

2. The resistance(R) multiplied by cross sectional area (A) over the length of the wire (l)

Power

Rate of work done

Watt

Power when one joule is transferred in one second

Kirchhoffs first law

The sum of the currents entering a junction equals the sum of the currents leaving that junction

Kirchhoffs second law

In any closed loop the sum of the emf’s is equal to the sum of the potential difference drops in that loop

emf

Chemical energy converted to electrical energy per coulomb of charge when passing through a power supply

Internal resistance

Resistance of materials within battery

Terminal p.d

The electrical energy per unit charge delivered by the source to the external circuit

Volt

1 joule per coloumb

Ohm

1 volt per ampere