Conduction is due to the movement of the free electrons (transferring charge around a circuit);
metals are a good electrical conductor with large numbers of free electrons;
insulators are bad conductors with few/no free electrons;
Define electromotive force (emf)
The work done per unit charge in moving a quantity of charge completely around a circuit / the power delivered per unit current / work done per unit charge made available by the source;
Describe how the resistance of a wire leads to a greater dissipation of power.
The resistance of a conductor increases with increasing temperature;
increased power (dissipation) leads to a higher temperature in the resistor / resistor heating up;
Define ideal ammeter and ideal voltmeter
Ideal ammeter has zero resistance;
ideal voltmeter has infinite resistance;
Define electronvolt
The energy gained by an electron when accelerated through an electric field with a potential difference of 1V;
1.6x10^-19J;
The definition of the ampere refers to
The force between parallel current-carrying conductors;
State Ohm's Law
The voltage is (directly) proportional to current / the ratio of potential difference to current is a constant called resistance / the resistance of a conductor is constant provided its temperature is
constant;
Describe a potential divider.
Consists of two resistors in series or a potentiometer;