Electric current

THE GENERALIZATION OF THE LAWS

The potential difference can be understood as the energy which can be extracted from each unit of charge which passes through a circuit. Therefore the power output is P= V·I where V is the potential difference and I is the current (I is typically used as a symbol for the current, from the German word Intensität, which means 'intensity').

At the same time we call the energy consumed for each unit of charge which passes through the circuit the the electromotive force of a generator. So the power supplied by a generator or battery will be:

Pg= EMF ·I

where we have called the electromotive force EMF.

Are EMF and V equal? Is the power consumed in the circuit equal to that supplied by the generator? The two answers are linked.

Click on next to find out the answer

	The hydraulic simile
	Elements in the circuit
	Characteristic magnitudes
	Conclusions

	Ohm's law
	Power and energy in the circuit
	The generalization of the laws
	Conclusions

	The arrangement of resistances
	The arrangement of generators
	A combined circuit
	Conclusions