potential difference
a measure of the electrical potential energy transferred to or from an electron when it is moving between two points in a circuit
effects of electric current
heating effect → energy transferred to a resistor as internal energy
magnetic effect
chemical effect
ohm’s law
the potential difference across a metallic conductor is directly proportional to the current in the conductor, providing that the physical conditions of the conductor don't change
the resistance of a conductor is
proportional to its length
inversely proportional to its cross-sectional area
thermistor
resistance varies with temperature; temp increases, resistance falls
LDR
resistance varies with light intesnsity; light intensity increases, resistance falls
emf
the terminal potential difference when no current is supplied