Summary
Electric current: continuos flow of electric charges (need an electric current source: battery or generator)
two types of currents direct (DC) and alternative (AC)
electric charges can flow continuously only when there is a complete circuit
electric current: amount of charge flowing through the wire per unit time
the voltage between two points is the electric potential difference
the resistance of the circuit determines the electric current (units: ?)
Ohm’s law: V=IR; R characterizes the wires and useful elements.
Most charges flow through the path with the least resistance
Charge conservation implies current conservation in electric circuits
the resistance of wires increases with increasing length, decreases with increasing cross-section and depends on the material type and temperature
basic circuits: serial and parallel or combined ones
power is the rate of using energy, Energy=Power x time
power can be measured in Watts, household energy is measured in kWh
Part I:514/2-5,7-10,14-16; 515/17-32; 517/1,2,5-12
Part II: 515/33-40; 516/41-50; 517/53-60; 517/13-17; 518/18-26